Alcheringa
For Peer Review OnlyA plesiosaurian assemblage from the Upper Jurassic
(Oxfordian) of southwestern Gondwana, Tarapacá Basin,
northern Chile
Journal: Alcheringa
Manuscript ID TALC-2017-0022
Manuscript Type: Standard Research Article
Date Submitted by the Author: 12-Apr-2017
Complete List of Authors: OTERO, RODRIGO; Universidad de Chile, Laboratorio de Ontogenia y
Filogenia, Departamento de Biología, Facultad de Ciencias; Museo de
Historia Natural y Cultural del Desierto de Atacama
Soto-Acuña, Sergio; Universidad de Chile, Biology; Museo de Historia
Natural y Cultural del Desierto de Atacama
Rojas M., Osvaldo; Museo de Historia Natural y Cultural del Desierto de
Atacama
Keywords: Marine reptiles, Gondwana, Upper Jurassic, Biogeography, Diversity
URL: http://mc.manuscriptcentral.com/talc E-mail: [email protected]
Page 1 of 57 Alcheringa
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3 A plesiosaurian assemblage from the Upper Jurassic (Oxfordian) of
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6 southwestern Gondwana, Tarapacá Basin, northern Chile
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15 RODRIGO A. OTERO, SERGIO SOTO-ACUÑA and OSVALDO ROJAS M.
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20 OTERO, R. A., SOTO ACUÑA, S. & ROJAS M., O. 201x. A plesiosaurian assemblage from the
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22 Upper Jurassic (Oxfordian) of southwestern Gondwana, Tarapacá Basin, northern Chile.
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24 Alcheringa xx.
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29 This paper describes four different plesiosaurian morphotypes recovered from marine
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32 strata of Oxfordian age in northern Chile. A partial articulated postcranial skeleton shows
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34 derived traits found among elasmosaurids, but retaining few characters shared with
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36 cryptoclidids but not present in leptocleidians. Due to this, it is identified as a xenopsarian.
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39 A second specimen comprising a cervical-dorsal articulated series is identified as an
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41 elasmosaurid. Both records support the divergence of the main xenopsarian lineages
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43 (Elasmosauridae and Leptocleidia) at least during the Oxfordian or even before. This
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46 means 18 Ma before the previously documented occurrence of any elasmosaurid or
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48 leptocleidid. A third specimen from the same unit and age comprises a mandible fragment
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51 referable to a pliosaurid, being the oldest record of this clade in Gondwana. Finally, a
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53 fourth morphotype is recognized through few fragmentary specimens. Among them, the
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55 presence of teeth with soft enamel (without labial striations), and ventrally-acute dorsal
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58 vertebrae with broad neural pedicels and dorsomedially expanded transverse processes are
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Alcheringa Page 2 of 57
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3 features commonly found among cryptoclidids. The plesiosaurian assemblage from the
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6 Oxfordian of northern Chile shows biogeographic affinities with coeval records from Cuba
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8 and northern Tethys, supporting the full establishment of the Caribbean Seaway during
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10 the Oxfordian and allowing the interchange of marine vertebrate fauna between both
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13 hemispheres.
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15 Rodrigo A. Otero [[email protected]], Red Paleontológica U-Chile. Laboratorio de
16 Ontogenia y Filogenia, Departamento de Biología, Facultad de Ciencias, Universidad de
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18 Chile, Av. Las Palmeras 3425, Santiago, Chile; Museo de Historia Natural y Cultural del
19 Desierto de Atacama. Interior Parque El Loa S/n, Calama, Chile. Sergio Soto Acuña
20 [[email protected]], Red Paleontológica U-Chile. Laboratorio de Ontogenia y
21 Filogenia, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Av. Las
22 Palmeras 3425, Santiago, Chile; Museo de Historia Natural y Cultural del Desierto de
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24 Atacama. Interior Parque El Loa S/n, Calama, Chile. Osvaldo Rojas M.
25 [[email protected]], Museo de Historia Natural y Cultural del Desierto de Atacama.
26 Interior Parque El Loa S/n, Calama, Chile; accepted XX.XX.XX
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28 Key words: Marine reptiles, Gondwana, Upper Jurassic, Biogeography, Diversity.
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33 CRETACEOUS diversity of plesiosaurians is restricted to three clades which were originated
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35 during the Jurassic (Benson and Druckenmiller, 2014). During the Early Cretaceous, two of
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37 them, the Brachaucheninae as well as the Cryptoclididae, were reduced in diversity and finally
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40 became extinct. A third clade, the Xenopsaria, became diversified in some moment prior to the
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42 Jurassic-Cretaceous boundary. Xenopsarians include the two most diverse and abundant
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45 Cretaceous plesiosaurian clades, the Leptocleidia (Leptocleididae + Polycotylidae) and the
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47 Elasmosauridae, which spanned until the K/Pg boundary and included the last plesiosaurians that
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49 ever existed. Despite the great abundance of informative xenopsarian specimens during the
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52 Cretaceous (and especially during the Late Cretaceous), the origin of the Xenopsaria is still
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54 obscure. The same occurs with the point of divergence between their internal clades, the
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56 Elasmosauridae and the Leptocleidia. Furthermore, the fossil record of elasmosaurids is
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Page 3 of 57 Alcheringa
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3 especially sparse during the Lower Cretaceous, being restricted only to fragmentary specimens,
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6 while putative Jurassic occurrences are represented by isolated vertebrae. This much incomplete
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8 record makes difficult the proposal of any hypothesis regarding the early evolution of the
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10 Elasmosauridae.
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13 This paper describes a new plesiosaurian assemblage from the Upper Jurassic of northern
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15 Chile. The recovered specimens include: i) the first known Oxfordian record of a cryptoclidian
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17 with intermediate features between cryptoclidids and xenopsarians; ii) The first Gondwanic
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20 record of an elasmosaurid of Oxfordian age, which allows us to link it with previous Bajocian
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22 and Callovian records in the Southern Hemisphere; iii) the oldest occurrence of a pliosaurid in
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24 Gondwana; iv) and, the first occurrence of Oxfordian cryptoclidids in the Tarapacá Basin. These
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27 records provide the first insights about the early evolution of the Xenopsaria, showing that
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29 cryptoclidid-xenopsarian intermediates, basal elasmosaurids as well as proper cryptoclidids,
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32 cohabited during the Oxfordian in the Tarapacá Basin. The new evidence strongly supports a
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34 divergence of the Elasmosauridae (and in consequence, of the Xenopsaria) prior to the
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36 Oxfordian. Such hypothesis is reinforced by previous Gondwanic records of putative
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39 elasmosaurids represented by isolated axial elements. The new articulated elasmosaurid material
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41 from northern Chile can be compared with previous records from the Southern Hemisphere,
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43 recognizing very similar morphologies between them. This also suggests that the elasmosaurid
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46 vertebral morphotype was already acquired among some cryptoclidians much before the
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48 Jurassic-Cretaceous boundary. In addition, this new material gives additional support to the
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50 existence of a faunal interchange between the north-Tethyan basins and southwestern Gondwana
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53 through the Caribbean Seaway.
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3 Locality and geological setting
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9 Five localities in the area of Cerritos Bayos, west Calama, have yielded vertebrate remains
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11 including the material here studied: i) Cerro Campamento; ii) Quebrada Campamento; iii) Cerro
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13 Amarillo; iv) a fourth previously unnamed locality assigned here with the field name of Biese 3;
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16 v) Loma Larga. These are placed near 30 km west from Calama, in the Antofagasta Region,
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18 northern Chile (Fig. 1).
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23 Cerro Campamento. Two fragmentary specimens, MUHNCAL.20146 and MUHNCAL.20172,
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25 were recovered from this locality. They are included in a grey to yellowish calcareous sandstone,
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28 in association to frequent fragmocones of the ammonoid 'Perisphinctes' andium Steinmann, 1881
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30 (=Vinialesphinctinae gen. et sp. indet. in Meléndez and Myczynski, 1987). This ammonoid was
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32 later reassigned to Perisphinctes prophetae by Gygi and Hillebrandt (1991), and more recently,
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35 to Subvinialesphinctes prophetae by Parent et al. (2006). This study follows the later
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37 identification for subsequent mentions. Biese (1957; 1961) provided a geologic map for the area
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39 of Cerritos Bayos. Particularly, for Cerro Campamento, this author described from base to roof:
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42 sandy limestones, red to yellowish, with levels of conglomerate limestones and septarian
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44 concretions. This level includes a bank of Gryphaea. This section is overlaid by light limestones
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47 with banks of dark-grey limestones. From base to roof, the faunal succession includes 'Piso de
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49 Cosmoceras' (='Cosmoceras' bed; the genus should be Kosmoceras), a' belemnite' limestone
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51 (likely Belemnopsis), a bank of Echinozoa, and a bank of Modiola. According to Biese (1957;
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54 1961) the upper levels of Cerro Campamento are comprised by compact, dark-grey oolitic
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56 limestones, which include a limestone with Spongiae.
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Page 5 of 57 Alcheringa
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3 Field information collected during this research slightly differs in age from the geologic
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6 description of Cerro Campamento provided by Biese (1957; 1961). On basal levels of the
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8 section, we found a bank of non-Gryphaea ostreids. The mid-section indeed has septarian
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10 concretions and limestones (regarded by Biese as containing 'Cosmoceras', 'belemnites',
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13 Echinozoa and Modiola); however, the latter section was found to include sparse indeterminate
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15 belemnoids, abundant fragmocones of Subvinialesphinctes prophetae and less frequent remains
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17 of Euaspidoceras. No ammonoid specimens similar to Kosmoceras have been found. Together
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20 with these cephalopods, frequent bone remains occur, including MUHNCAL.20146 and
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22 MUHNCAL.20172. The roof of the section has few incomplete beds of dark shales with gypsum
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24 dikes and stocks. The latter are consistent with the upsection of the Oxfordian stage described by
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27 Biese (1961: p. 25). This author indicates an upper Callovian age for the levels cropping out in
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29 Cerro Campamento. However, the presence of S. prophetae and Euaspidoceras is consistent with
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32 higher levels of the succession, and indicates a middle Oxfordian age. Associated vertebrates
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34 include remains of large filter-feeder osteichthyans (Ossa-Fuentes et al., 2015), metriorhynchid
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36 crocodiles (Soto-Acuña et al., 2015), pterosaur remains (Alarcón et al., 2015) and sparse
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39 ichthyosaur vertebrae.
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43 Quebrada Campamento. MUHNCAL.20175 was collected from this locality. It comprises
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46 scattered fragments of a single individual including dorsal vertebrae, ribs and gastralia embedded
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48 in a single concretion. The block has a matrix of red, very hard, fine, calcareous and partially
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50 laminated limestone. Associated fauna includes abundant fragmocones of S. prophetae, most of
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53 them in isolated and transported concretions; however, the latter are abundant in the fossil-
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55 bearing level. The placement of the fossil find, the recognized lithology as well as the presence
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58 of concretions are consistent with the level of red limestones with limestone banks and
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3 calcareous concretions described as overlying the "Aspidoceras-Kalk" (=Aspidoceras limestone).
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6 This research agrees with Biese (1961), recognizing a middle-to-upper Oxfordian age for this
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8 fossil-bearing level.
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13 Cerro Amarillo. MUHNCAL.20174 was collected from yellowish to red calcareous siltstones,
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15 filled with gypsum veins, limonite and other iron oxides. Taphonomic conditions differ from all
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17 other studied localities, occurring mostly articulated vertebrate remains. A second specimen
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20 found few meters south in the same level, is represented by a partial thalattosuchian skull with
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22 associated vertebrae (under study by the authors). Scattered ichthyosaur vertebrae were also
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24 found. Associated ammonoids are mostly represented by S. prophetae and Euaspidoceras sp.
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27 The previous description by Biese (1961) for this section indicates an equivalence with the
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29 putative 'Callovian' section of Cerro Campamento. We recognize similar fauna of ammonoids (S.
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32 prophetae and Euaspidoceras sp.); however, the lithology is more similar to that described for
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34 the Oxfordian upper levels of Biese's section. This, plus the presence of gypsum veins, suggests
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36 a regressive event consistent with that recorded in the upper black shales of the Cerro
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39 Campamento section, characterized by abundant gypsum. Therefore, an upper Oxfordian age is
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41 assigned to this vertebrate-bearing level. Its lithology is also correlated with that associated to
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43 MUHNCAL.20175 from Quebrada Campamento.
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48 Biese 3. MUHNCAL.20176 was collected from this locality. The specimen was contained in a
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50 large concretion of limestone. In addition, concretions are very abundant in the hosting level.
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53 Associated fauna includes fragmentary vertebrate remains referable to indeterminate
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55 ichthyosaurians. Invertebrates include S. prophetae and Euaspidoceras. Following the geologic
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58 map and section described by Biese (1961), this locality has the same lithology described for
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Page 7 of 57 Alcheringa
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3 Quebrada Campamento. Such observation is here verified and in consequence, the fossil-bearing
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6 level including MUHNCAL.20176 is assigned to the middle-to-upper Oxfordian.
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10 Loma Larga. MUHNCAL.20181 was found in this locality. The material was found in a
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13 fragment of a large concretion broken by effect of erosive processes. This has a matrix of dark-
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15 grey calcareous limestone. Following Biese (1961), the fossil-bearing level is part of the oolitic
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17 limestones with Spongiae. However, the material occurs in concretions and associated to S.
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20 prophetae. Therefore, we reassign the age to the lower Oxfordian, while the occurrence of the
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22 material likely belongs to the 'Perisphinctes-Kalk' of Biese (1961). Associated vertebrates
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24 comprise gill-rakers of large filter-feeding osteichthyans (Ossa-Fuentes et al., 2015). All these
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27 finds plus the ammonoid-bearing levels were integrated in a general stratigraphic section (Fig.
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29 2A), with estimated thicknesses based in Biese (1961). Also, representative ammonoids found in
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32 association with the vertebrate remains, are presented on Fig. 2B-E.
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36 Institutional Abbreviations. AMNH, American Museum of Natural History, New York, USA;
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39 GWWU, Geomuseum der Westfaelischen Wilhems-Universitaet, Münster, Germany; HMG V,
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41 Hunterian Museum, University of Glasgow, Scotland; MOZ, Museo Olsacher, Zapala,
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43 Argentina; MUHNCAL, Museo de Historia Natural y Cultural del Desierto de Atacama, Calama,
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46 Chile; NHMUK, National History Museum, London, UK; NMV, Melbourne Museum,
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48 Melbourne, Australia; QM, Queensland Museum, Brisbane, Australia; SGO.PV, Área de
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50 Paleontología, Museo Nacional de Historia Natural, Santiago, Chile; SGU, Saratov State
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53 University, Russia; UCMP, University of California, Museum of Paleontology, USA; WAM,
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55 Western Australia Museum, Department of Geology, University of Western Australia.
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6 Systematic Paleontology
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11 DIAPSIDA Osborn, 1903
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13 SAUROPTERYGIA Owen, 1860
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16 PLESIOSAURIA de Blainville, 1835
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18 PLIOSAURIDAE Seeley, 1874
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23 Pliosauridae indet.
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25 (Fig. 3)
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30 Material. MUHNCAL.20181. A fragment of a left dentary.
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35 Locality, horizon and age. Loma Larga, 30 km southwest Calama, northern Chile. Cerritos
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37 Bayos Formation, levels with S. prophetae and Euaspidoceras. Middle-to-upper Oxfordian.
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42 PLESIOSAUROIDEA Welles, 1943
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44 CRYPTOCLIDIA Ketchum and Benson, 2010
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47 CRYPTOCLIDIDAE Williston, 1925
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51 Cryptoclididae indet.
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54 (Fig. 4)
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3 Material. MUHNCAL.20146. Fragmentary left dentary preserving four teeth;
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6 MUHNCAL.20172. One isolated dorsal centrum; MUHNCAL.20175, associated remains of a
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8 single individual including dorsal and pectoral vertebrae, ribs and gastralia embedded in a single
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10 block.
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15 Locality, horizon and age. MUHNCAL.20146 and MUHNCAL 20172 were recovered from
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17 Cerro Campamento, Cerritos Bayos. Middle-to upper Oxfordian. MUHNCAL.20175, was
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20 recovered from Quebrada Campamento (Campamento Ravine), Cerritos Bayos. Both specimens
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22 recovered from middle levels of the Cerritos Bayos Formation. Middle-to-upper Oxfordian.
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27 XENOPSARIA Benson and Druckenmiller, 2014
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32 Xenopsaria indet.
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34 (Figs. 5-7)
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39 Material. MUHNCAL.20176. Partial articulated postcranial skeleton.
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43 Locality, horizon and age. Field denomination as "Biese 3", in the area of Cerritos Bayos, 30 km
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46 southwest Calama, northern Chile. Cerritos Bayos Formation, upper levels with S. prophetae.
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48 Upper Oxfordian.
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53 ELASMOSAURIDAE Cope, 1869
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58 Elasmosauridae indet.
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3 (Figs. 8-9)
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8 Material. MUHNCAL.20174. Eleven articulated vertebrae from the posterior part of the neck
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10 and the anterior part of the trunk.
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15 Locality, horizon and age. Cerro Amarillo, Cerritos Bayos locality, 30 km southwest Calama,
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17 northern Chile. Cerritos Bayos Formation, levels with S. prophetae and Euaspidoceras. Middle-
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20 to-upper Oxfordian.
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25 Description of the studied specimens
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30 Pliosauridae indet. (MUHNCAL.20181)
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32 This comprises a fragment of the left dentary. The ontogenetic age of the specimen is difficult to
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35 assess due to preservation. It is exposed in an oblique, dorsolingual view, which causes the view
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37 of the alveoli in oblique cross-section. Five alveoli are visible in dorsal view, with a sixth
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39 alveolus only visible in anterior view. One partial tooth is preserved, showing a sub-circular
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42 cross-section and enamel with parallel ridges. The alveoli are surrounded by porous tissue
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44 interpreted as part of the paradental plate. The anterior part of the preserved portion has a marked
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47 rostral inflection over its labial surface. Over its ventrolingual margin, a lingual process is clearly
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49 visible (Fig. 3). This is consistent with the anterior articular margin of a laminar element
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51 (coronoid or splenial). The presence of this articular contact shows that the participation of the
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54 coronoid or the splenial is precluded from the symphysis, the latter being formed exclusively by
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56 the dentaries.
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6 Cryptoclididae indet. (MUHNCAL.20175)
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8 This material is preserved in a single block. A complete dorsal vertebra is naturally exposed in
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10 anterior view (Figs. 4A, B). The latter has a subcircular articular outline. As in the case of
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13 MUHNCAL.20172, the centrum has a shallow ventral keel, while the neural pedicels are well-
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15 separated. These are as broad as the centrum. The transverse processes are massive and strongly
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17 fused to the centrum, indicating an adult stage for this individual, following the criteria of Brown
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20 (1981). The neural canal is broad, suboval, with its larger axis being the vertical. The neural
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22 spine appears as a subtriangular outline in anterior view. This is massive and low, with a groove
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24 over its dorsal end. The vertebra visible in the opposite side of the block shows thick neural
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27 pedicels and absence of transverse processes or ventrolateral rib facets, suggesting that this
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29 belongs to a pectoral centrum (Figs. 4C, D).
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34 Cryptoclididae indet. (MUHNCAL.20172)
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36 This isolated centrum (Fig. 4B) preserves part of their neural pedicels, which are as broad as the
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39 centrum. These are well-separated and placed over the laterodorsal edges of the centrum, leaving
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41 a large space for the neural canal. The centrum is subcircular in articular view, with a low ventral
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43 keel. Articular facets are platycoelous. The incompleteness of the transverse processes makes
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46 difficult assessing the ontogenetic age of the specimen.
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50 Cryptoclididae indet. (MUHNCAL.20146)
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53 This is a small fragment of a dentary preserving four teeth in anatomical position, exposed on
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55 labial view (Fig. 4C). The teeth show partial erosion over its labial surface, however, two of
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58 them have well-preserved enamel showing a smooth labial surface. The tooth crown tips are all
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3 consistently recurved. Based on this, we interpret the curving orientation as the caudal direction,
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6 as is seen in almost all plesiosaurians. Subsequently, we assign a left laterality to the material.
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8 The anteriormost preserved tooth lacks its tip, allowing observing the presence of fine, parallel
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10 grooves over the limestone cast, thus, indicating that the lingual tip bears fine striations. The
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13 alveolar tissue surrounding every tooth has a different compactness with respect to the rest of the
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15 preserved bone, indicating the presence of a paradental plate.
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20 Xenopsaria indet. (MUHNCAL 20176)
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22 Ontogenetic stage. This specimen (Figs. 5-7) has their neurocentral sutures lost at least in the
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24 cervical and dorsal vertebrae, on the basis of their respective preserved moulds. On the other
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27 hand, the humeri have poorly defined distal articulated facets, while their humeral proximal
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29 articulations are well-defined, with a tuberosity separated from the humeral head.
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32 These characters are contradictory in terms of an ontogenetic inference. The craniocaudal pattern
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34 of neurocentral fusion typical of sauropterygians can be only verified in the neck and the anterior
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36 trunk, indicating at least a young, nearly adult condition. On the other hand, the immature
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39 humerus could reflect a paedomorphic condition.
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43 Axial skeleton. Measurements of the preserved axial elements are not informative because the
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46 centrum breadth cannot be assessed, precluding any interpretation of the centrum proportions.
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48 The cervical vertebrae are mostly preserved as moulds. These are longer than high. Neural spines
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50 are higher than their respective centra, however, none of them is complete, making difficult to
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53 evaluate the proportion between neural spines and the height of the centra. The neural pedicels
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55 are anteriorly displaced and also recurved rostrally. The base of the cervical neural spines are
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58 axially narrow, reaching near the half of the centrum length. The prezygapophyses are very sharp
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3 and they extend anteriorly, overlapping near the half of the next anterior centrum. The
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6 postzygapophyses are also expanded posteriorly, but their extension is comparatively shorter
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8 than that of the prezygapophyses. The neural spines of the last cervical vertebrae are strongly
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10 recurved rostrally. They have an almost squared contour with a small bulk in their anteroventral
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13 margin. At least three pectoral vertebrae are recognized, based on the intermediate neurocentral
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15 position of their transverse processes. The transverse processes become thicker on each
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17 successive posterior pectoral vertebra. The outline of one dorsal vertebra is also preserved,
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20 showing a neural spine dorsoventrally straight instead being recurved cranially as it occurs in
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22 cervical vertebrae. A fragment of a second dorsal centrum is also preserved.
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27 Ribs. Four dorsal ribs are preserved in a following block. The cast of the ribs indicate the
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29 presence of a proximal portion nearly straight, from which a dorsal keel rises, while the rest of
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32 each rib becomes ventrally curved.
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36 Propodials. Two propodials have been interpreted as both humeri based on the articulated
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39 occurrence of the specimen. They are preserved as moulds with part of few bony portions
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41 attached. One of them interpreted as a left humerus is preserved on ventral view. Its articular
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43 head is broader than the mid part of the shaft. The distal part is near 1.5 times broader than the
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46 rest of the shaft. It has poorly defined articular facets, being consistent with a juvenile or a
47
48 paedomorphic condition. The second propodial, here interpreted as the right humerus, is
49
50 preserved as a partial mould in oblique position. This includes only its proximal end and part of
51
52
53 the shaft. The proximal end allows us to observe the tuberosity, which is slightly higher than the
54
55 humeral head. The latter has a flat articular surface.
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3 Elasmosauridae indet. (MUHNCAL 20174)
4
5
6 Ontogenetic stage. All the preserved vertebrae of this specimen (Figs. 8, 9) has strong
7
8 neurocentral fusion without visible sutures. Following the osteological criteria of Brown (1981),
9
10 this specimen can be referred as an adult.
11
12
13
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15 Cervical vertebrae. Measurements of the preserved axial elements are summarized in Table 1.
16
17 Five unambiguous cervical vertebrae are preserved. The anteriormost element is represented by a
18
19
20 fragmentary centrum, slightly deformed laterally. This has a subtriangular articular contour, with
21
22 a neural arch breadth less than one third of the centrum breadth. The ventral surface of the neural
23
24 canal is preserved, being subcircular in contour. The posterior articular facet of this centrum is
25
26
27 missing due to erosion, however, the preserved part allow recognizing a length greater than the
28
29 height. Part of the respective cervical rib is preserved, being strongly fused and without any
30
31
32 visible suture. Four additional cervicals are fairly complete. Three of them preserve their neural
33
34 spines as well as the pre- and postzygapophyses. The prezygapophyses are cranially extended
35
36 and overlaps ca. one third of the immediately anterior centrum. The neural pedicels are cranially
37
38
39 displaced, leaving a short gap in the posterodorsal surface of the centrum. Based on the available
40
41 neural spines, one of them shows that these are dorsoventrally higher than the centra. Each
42
43 centrum is longer than high and broader than long than high, with an average VLI index (sensu
44
45
46 Welles, 1952) of 98.8 (based on the four complete centra preserved). The ventral surface of the
47
48 cervical centra is slightly convex, with a pair of oval foramina separated by a bony bridge instead
49
50 of a ventral keel. The neural arches are less than the half of the centrum breadth. These have
51
52
53 prezygapophyses laterally narrower than the neural pedicels. The prezygapophyses are recurved
54
55 dorsally and have a medial septum that separate them. The neural canal is subtriangular with
56
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58
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3 rounded edges. The neural pedicels are very thin, near one fourth the ventral breadth of the
4
5
6 neural canal.
7
8
9
10 Pectoral vertebrae. Four pectoral vertebrae are preserved. The anteriormost pectoral centrum is
11
12
13 fragmentary, but this is still attached to the last cervical centrum. From the latter, the rib facet
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15 joins to the transverse process, forming a facet between the neural spine and the centrum. This
16
17 facet is dorsally circular and becomes sharp and ventroposteriorly recurved. The dorsal margin
18
19
20 of the pectoral facets has an anterodorsal ridge that rises from the anterior margin of the facet
21
22 into the dorsal part of the neural spine. The pectoral centra are comparatively shorter than the
23
24 cervicals. They also acquire a more oval articular contour. The neural canal is narrower than in
25
26
27 the cervical vertebrae, while the neural pedicels are as thin as those of the cervicals.
28
29
30
31
32 Dorsal vertebrae. Two unambiguous dorsal vertebrae are preserved. Thes have nearly circular
33
34 articular facets. Their transverse processes are oriented almost horizontally, being gracile and not
35
36 expanded distally. These centra are as high as broad and longer than broad than high. In their
37
38
39 anterior articular facets, both dorsal vertebrae have a central scar.
40
41
42
43 Discussion
44
45
46
47
48
49 Taxonomic assignation of MUHNCAL.20176 to Xenopsaria indet. MUHNCAL.20176 has
50
51 interesting morphologic traits. First, their cervical vertebrae have neural spines rostrally
52
53
54 recurved. So far, such trait was only observed among Late Cretaceous elasmosaurids such
55
56 Aristonectes quiriquinensis and Kaiwhekea katiki (Cruickshank and Fordyce, 2002; Otero et al.,
57
58
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2
3 2014). Also, MUHNCAL.20176 has cervical vertebrae with anteriorly sharp prezygapophyses,
4
5
6 which overlap the immediately anterior centrum. Their postzygapophyses do not extend beyond
7
8 their respective centrum length. Comparison of MUHNCAL.20176 prezygapophyses with those
9
10 of cryptoclidids such Cryptoclidus eurymerus (Fig. 6C) and Muraenosaurus leedsi (Fig. 6D)
11
12
13 shows evident differences. In both cryptoclidids, the prezygapophyses are comparatively rounder
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15 and scarcely overlapping over the immediately anterior centrum. On the other hand, comparison
16
17 with leptocleidids such Brancasaurus brancai (Fig. 6E) and Nichollsaura borealis (Fig. 6F)
18
19
20 shows that both leptocleidids also have anteriorly shorter and rounded prezygapophyses, while
21
22 the postzygapophyses indeed overlap the immediately posterior centrum, and their neural spines
23
24 are markedly recurved caudally.
25
26
27 The propodials of MUHNCAL.20176 are also informative. While the cervical neurocentral
28
29 fusion suggests an adult or near adult stage for this specimen, the left humerus (Fig. 7A) shows a
30
31
32 paedomorphic condition. This has a prominent proximal articular head that suggest an adult
33
34 condition; however, its distal end has undifferentiated facets, while the diaphysis is thick with a
35
36 poorly expanded distal end. The articular head of the right humerus (Fig. 7B) has a flattened
37
38
39 articular head with a differentiated trochanter, thus, supporting an adult or nearly adult
40
41 ontogenetic stage due to the acquisition of well-defined articular features. The humeral distal
42
43 outline without differentiated facets is similar to that observed in early ontogenetic stages of
44
45
46 Cryptoclidus eurymerus (Fig. 7C). In addition, the articular head as well as the trochanter of
47
48 MUHNCAL.20176 are very similar to those observed on several cryptoclidids such Cryptoclidus
49
50 eurymerus, Cryptoclidus richardsoni, Muraenosaurus leedsi, Microcleidus beloclis, Tricleidus
51
52
53 seeleyi, Colymbosaurus trochanterius, Spitrasaurus wensaasi, ventral view (Fig 7D-J). On the
54
55 other hand, comparison of the MUHNCAL.20176 humeri with few Cretaceous elasmosaurids
56
57
58 shows differences in the proximal articular heads as well as in the trochanter shapes (Fig. 7K-N).
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3 Thus, MUHNCAL.20176 has an unusual combination of characters: it has cervical vertebrae
4
5
6 clearly different from cryptoclidids and leptocleidids but ressemblant of elasmosaurids; also, it
7
8 has paedomorphic propodials with proximal articular heads very similar to cryptoclidids. Such
9
10 combination of characters suggest MUHNCAL.20176 as an ancestor of both cryptoclidids and
11
12
13 elasmosaurids, therefore, it can be included in the clade Cryptoclidia (sensu Benson and
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15 Druckenmiller, 2014). In addition, the much derived features observed on the cervical vertebrae,
16
17 particularly the sharp and anteriorly projected prezygapophyses and the rostrally recurved neural
18
19
20 spines, are traits commonly found among elasmosaurids. The specimen is too fragmentary for
21
22 confidently referring it to the clade Elasmosauridae, however, the presence of these derived
23
24 characters suggest that this specimen belongs to a more derived cryptoclidian related to
25
26
27 Cretaceous taxa but excluded from Leptocleidia. Therefore, here it is identified as an
28
29 indeterminate xenopsarian plesiosaurian.
30
31
32
33
34 Taxonomic assignation of MUHNCAL.20174 to Elasmosauridae indet. The dorsal vertebrae of
35
36 MUHNCAL.20174 cannot be considered as diagnostic beyond family-level; however, they share
37
38
39 morphologic characters with most elasmosaurids. The neural canal becomes very narrow (less
40
41 than one third the centrum breadth). The transition from cervical to dorsal vertebrae (Fig. 8A-D)
42
43 shows rib facets that are oval and axially expanded, passing then to a more dorsoventrally
44
45
46 elongated facet and acquiring an 'eight-shaped' facet outline in the pectoral vertebrae, prior to
47
48 fully migrate into the neural arch in the dorsal vertebrae. Such morphologies have been described
49
50 among elasmosaurids (Welles, 1943; 1952; 1962). However, such change in the rib facet outline
51
52
53 is also present on Muraenosaurus (Andrews, 1910: text-fig. 52), while in Cryptoclidus, this
54
55 transition shows 'eight-shaped' rib facets but comparatively more compressed extended
56
57
58 dorsoventrally (Brown, 1981: fig. 9).
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60 17
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2
3 The vertebrae of MUHNCAL.20174 possess cervical centra which are broader than high and
4
5
6 similarly high than long. Their articular facets become progressively oval in successive posterior
7
8 cervical centra (Fig. 9A-E). These do not acquire a bilobed outline as it happens on derived Late
9
10 Cretaceous elasmosaurids (Gasparini et al., 2003). However, the oval outline of posterior
11
12
13 cervicals indeed occur in more basal Cretaceous elasmosaurids such Callawayasaurus
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15 colombiensis from the Aptian of Colombia (Welles, 1962) and the elasmosaurid which is the
16
17 type specimen of 'Cimoliasaurus maccoyi' (nomen dubium), from the Aptian of Australia
18
19
20 (Etheridge, 1904; Kear, 2002). In addition, the pedicels of the neural canal are gracile, contrary
21
22 to the thick pedicels present in cryptoclidids (Andrews, 1910: text-fig. 50; Brown, 1981: fig. 8)
23
24 and leptocleidids (Wegner, 1914: tafel VII, figs. 2A and 2B; Hampe, 2013: fig. 5B). Additional
25
26
27 interesting features are present in the prezegapophyses in anterior view. In cryptoclidids and
28
29 leptocleidids, the combined prezygapophyseal breadth (CPB) reaches between half and two
30
31
32 thirds of the centrum breadth (Andrews, 1910: text-fig. 50; Brown, 1981: fig. 8; Wegner, 1914:
33
34 tafel VII, figs. 2A and 2B). On contrary, among Lower and mid Cretaceous elasmosaurids the
35
36 CPB reaches near the half of the centrum breadth (O'Gorman et al., 2015: fig. 4A; Welles, 1962:
37
38
39 plate 3c).
40
41 Within the Elasmosauridae, there is an evolutionary trend of the CPB to become even more
42
43 reduced. Late Cretaceous elasmosaurids from the Western Interior Sea of Kansas shows extreme
44
45
46 CPB values of near one third the centrum breadth (Welles, 1943: plate 27). Austral Late
47
48 Cretaceous elasmosaurids also have values close to a third the centrum breadth. Interestingly,
49
50 MUHNCAL.20174 shows a CPB very similar to that observed among derived elasmosaurids
51
52
53 (Fig. 9F, G). Quantification of these values was addressed through an index calculated by
54
55 dividing the CPB and the maximum centrum breadth. This was applied to those taxa of interest
56
57
58 for this discussion, which also preserves some entire cervical centra (Table 2). The
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3 incompleteness of few specimens, as well as the unavailable measurements of cervical centra
4
5
6 from the same anatomical position but from different taxa, makes difficult a more accurate
7
8 comparison. The assessed measurements show that cryptoclidids as well as leptocleidids possess
9
10 similar CPB/CB (combined prezygapophyseal breadth / centrum breadth) proportions (Table 2).
11
12
13 On contrary, lower values seem to be restricted to the Elasmosauridae, suggesting the existence
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15 of a trend in this clade for a progressive narrowing of the neural arch as well as the CPB with
16
17 respect to the centrum breadth. In this sense, MUHNCAL.20174 has proportions typical of
18
19
20 elasmosaurids. The summary of features here described support MUHNCAL.20174 as an
21
22 indeterminate elasmosaurid.
23
24
25
26
27 Taxonomical assignation of MUHNCAL.20181 to Pliosauridae indet. MUHNCAL.20181 has a
28
29 labial inflection of the dentary at the level of the posterior end of the symphysis, and the
30
31
32 presence of larger alveoli in this portion. The presence of a marked inflection over the labial
33
34 surface at the level of the posterior end of the symphysis, associated to the presence of laterally
35
36 expanded dentaries with larger alveoli, are only found among Middle-to-Upper Jurassic
37
38
39 pliosaurids (Fig. 10) and Lower Jurassic-Upper Jurassic rhomaleosaurids. The rostral
40
41 inflection is observed in few Kimmeridgian pliosaurid specimens from England BRSMG Cc332
42
43 referred to the genus Pliosaurus (Knutsen, 2012), and CAMSM J.35991 suggested as a
44
45
46 replacement type of Pliosaurus brachyspondylus (Tarlo, 1959; Knutsen, 2012). In addition, two
47
48 species within the genus, P. kevani and P. brachydeirus, both have a rostral inflection over their
49
50 labial surface marking the beginning of the symphysis (Benson et al., 2013; Owen, 1841).
51
52
53 However, in the latter taxa, this part lacks the lateral expansion and the larger symphyseal
54
55 alveoli. The only previously known Oxfordian pliosaurid skull pertains to Gallardosaurus
56
57
58 iturraldei from Cuba (Gasparini, 2009). Regretfully, this specimen does not preserve the rostrum
59
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3 neither the symphyseal part of the mandibles, making impossible any comparison with
4
5
6 MUHNCAL.20181. Among Callovian pliosaurids there are few representatives possessing
7
8 rostral inflection of the ramus and a lateral symphyseal expansion for larger alveoli. This trait is
9
10 present at least in Simolestes vorax (Andrews, 1909), and Liopleurodon ferox (Sauvage, 1879;
11
12
13 Tarlo, 1959), both from the Oxford Clay of England.
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15 In the case of Rhomaleosauridae, the mandibular rami have a very long splenial that
16
17 commonly reaches the symphysis or else, the anterior extension of the splenial barely reaches the
18
19
20 symphysis (as first coded by O'Keefe, 2001 for the clade 'Pliosauroidea'). Posteriorly, the
21
22 splenial ventrally overlaps the angular. This condition is indeed present among the Hettangian
23
24 rhomaleosaurid Anningasaura lymense (Vincent and Benson, 2012: fig. 2) with the splenial
25
26
27 extending posteriorly near the half of the rosette length, contacting posteriorly with the angular
28
29 along the labial ramus surface. A similar condition occurs in the Hettangian rhomaleosaurids
30
31
32 Atychodracon megacephalus (Smith, 2015: fig. 3) and Eurycleidus arcuatus (Cruickshank, 1994:
33
34 fig. 8), and in the lower Toarcian rhomaleosaurids Rhomaleosaurus cramptoni (Smith, 2007: fig.
35
36 4.2) and Meyerasaurus victor (Smith and Vincent, 2010: fig. 2). The condition persists in
37
38
39 derived rhomaleosaurids such as the Bajocian Maresaurus coccai (Gasparini, 1997: fig. 1) and
40
41 the Callovian Borealonectes ruselli (Sato and Wu, 2008: fig. 3).
42
43 On the other hand, basal Pliosauridae shows a different array of the mandibular ramus
44
45
46 elements. In the Rhaetian-Hettangian Thalassiodracon hawkinsi the splenial precludes the
47
48 symphysis. Also, the coronoid extends anterodorsally, reaching close to the symphysis (Benson
49
50 et al., 2011: fig. 2). In addition, the Toarcian Hauffiosaurus zanoni has a splenial that reaches the
51
52
53 symphysis, but their contacts are obscured (O'Keefe, 2001, Vincent, 2011: fig. 3). Among more
54
55 derived pliosaurids, the lower Callovian Marmonectes has a splenial that precludes the
56
57
58 symphysis, while the coronoid extends anterodorsally reaching close to the symphysis (Ketchum
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3 and Benson, 2011: fig. 3) in a similar way as it occurs in Thalassiodracon. Also, in the upper
4
5
6 Kimmeridgian Pliosaurus kevani, both the coronoid and the splenial extends anteriorly and
7
8 reaches close to the symphysis (Benson et al., 2013: fig. 16).
9
10 Based on these considerations, MUHNCAL.20181 can be segregated from Rhomaleosauridae
11
12
13 by lacking a splenial extended into the symphysis. On the other hand, the presence of a clear
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15 dentary process in the lingual surface of its left ramus is consistent with the articulation with
16
17 another laminar element (likely the coronoid or the splenial) in the dorsolingual part of the
18
19
20 ramus; however, the latter element is precluded from the symphysis in MUHNCAL.20181.
21
22 Based on the mandibular ramus anatomy of Pliosaurus kevani (Benson et al., 2015: fig. 16), this
23
24 missing element of MUHNCAL.20181 should be the coronoid. Moreover, the coronoid of few
25
26
27 derived pliosaurids indeed can reach the symphysis. This is the case of the lower Turonian
28
29 brachaucheniine Brachauchenius lucasi (Albright et al., 2007: fig. 4). Considering the topology
30
31
32 observed in the specimens commented above, the evolutionary trend suggest that the splenial
33
34 progressively reduced its anterior extension; also, this element progressively migrated to the
35
36 ventral part of the rami, and finally, its occlusal (dorsal) exposure in the symphysis became
37
38
39 precluded by the anterior extension of the coronoids that articulates directly with the dentary, as
40
41 shown by Albright et al. (2007: fig. 4) in derived pliosaurids. Therefore, the mandibular ramus of
42
43 MUHNCAL.20181 having a laminar dorsolingual element (likely the coronoid) articulating with
44
45
46 the dentary before reaching the symphysis, can be considered a pliosaurid intermediate between
47
48 basal pliosaurids (i.e., Thalassiodracon, Hauffiosaurus) and derived pliosaurids represented by
49
50 Brachaucheniinae (i.e., Brachauchenius lucasi).
51
52
53
54
55 Taxonomic assignation of MUHNCAL.20175, MUHNCAL.20172 and MUHNCAL.20146 to
56
57
58 Cryptoclididae indet. The pectoral vertebrae of MUHNCAL.20175 are clearly different from
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2
3 those of MUHNCAL.20174 (referred to Elasmosauridae indet.). The first possesses thick neural
4
5
6 pedicels, a neural arch as broad as the centrum, an oval neural canal dorsoventrally larger than
7
8 laterally broad, and prezygapophyses broadly separated, with an internal facet lacking any
9
10 septum. Auspiciously, MUHNCAL.20174 (Elasmosauridae indet.) also preserves pectoral
11
12
13 vertebrae; these have thin neural pedicels, a neural arch narrower than the centrum, laterally
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15 compressed prezygapophyses with a median septum, and a neural canal with a subtriangular
16
17 outline. Dorsal vertebrae of MUHNCAL.20175 and MUHNCAL.20172 also show in articular
18
19
20 view, neural arches as broad as the centrum. The same elements are much narrower than the
21
22 centrum breadth in MUHNCAL.20174. These differences allow a first segregation of
23
24 MUHNCAL.20172 and 20175 as a different morphotype than MUHNCAL.20174
25
26
27 (Elasmosauridae indet.). The presence of pectoral and dorsal vertebrae having neural arches as
28
29 broad as the centrum, is a feature commonly observed among cryptoclidids (Brown, 1981: figs.
30
31
32 9.1 and 9.4). The shape of the prezygapophysis and its width similar to the neural pedicel as
33
34 observed in MUHNCAL.20175, it is also coincident with the features described in Cryptoclidus
35
36 eurymerus (Brown, 1981: fig. 9.1). On the other hand, teeth preserved in MUHNCAL.20146 do
37
38
39 not show any lingual ornamentation or striations, as those described for C. eurymerus (Brown,
40
41 1981: fig. 5). Based on these features, MUHNCAL.20172, MUHNCAL.20172 and
42
43 MUHNCAL.20146 are here referred to Cryptoclididae indet.
44
45
46
47
48 Remarks about records of Elasmosauridae before the Late Cretaceous. A postcranial specimen
49
50 from the upper Triassic Wilczek Formation of Russia was referred by Sennikov and
51
52
53 Arkhangelsky (2010) to an elasmosaurid, Alexeyisaurus karnoushenkoi. This specimen possesses
54
55 amphycelous cervical centra with subcircular articular faces and slender propodials with their
56
57
58 distal ends not extended as it occurs in all cryptoclidians (Xenopsaria + Cryptoclididae). The
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3 coracoid, even when it shows a median posterior embayment, it is much different to any known
4
5
6 elasmosaurid or xenopsarian coracoid due of the complete absence of the anteromedial process
7
8 and the conical ventral process, as well as the presence of a much unusual dorsal process similar
9
10 to an articular facet (Sennikov and Arkhangelsky, 2010: fig. 3) Such structure is absent in all
11
12
13 known elasmosaurids. Thus, this specimen does not preserve unambiguous elasmosaurid traits,
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15 being difficult to assure its adscription to Elasmosauridae.
16
17 An isolated pectoral vertebra (WAM.86.10.707) from the Colalura Sandstone (Bajocian)
18
19
20 exposed on Geraldton, Australia, was tentatively referred to Elasmosauridae indet. (Long and
21
22 Cruickshank, 1998). Indeed, this vertebra has a remarkable similarity with pectoral centra found
23
24 among elasmosaurids throughout the Cretaceous. However, its isolated occurrence makes
25
26
27 difficult assuring its taxonomical assignation because similar pectoral vertebrae may be present
28
29 among other xenopsarians. Gasparini and Spalletti (1993) described few cervical vertebrae
30
31
32 (MOZ.6003, 6004 and 6006) from the Callovian of Chacaico, Argentina, referring them to cf.
33
34 Muraenosaurus and cf. Cryptoclidus, respectively. By then, the genus Muraenosaurus was
35
36 considered as within the Elasmosauridae. Muraenosaurus is currently obtained within the clade
37
38
39 Cryptoclididae, based on phylogenetic analyses (Ketchum and Benson, 2010; Benson and
40
41 Druckenmiller, 2014). Despite of the current taxonomical status of Muraenosaurus, the
42
43 determination of Gasparini and Spalletti (1993) of an elasmosaurid in the Callovian of Argentina
44
45
46 it is here addressed.
47
48 Wegner (1914) described a new genus and species, Brancasaurus brancai, from the
49
50 Berriasian of Gronau, Germany, based on a fairly complete skeleton. This was originally referred
51
52
53 to the Elasmosauridae. Currently, this taxon is considered as a leptocleidid based on
54
55 phylogenetic analyses (Ketchum and Benson, 2010; Benson and Druckenmiller, 2014; Sachs et
56
57
58 al., 2016). GWWU-A3 B2 is a fragmentary skeleton from the Berriasian of Germany. This was
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2
3 obtined within the Elasmosauridae by Benson and Druckenmiller (2014). Osteological
4
5
6 description of the same specimen revealed it as a new leptocleidid, Gronausaurus wegneri
7
8 Hampe, 2013; however, the latter has been referred to a second specimen of B. brancai by Sachs
9
10 et al. (2016). From Argentina, few upper Valanginian-lower Hauterivian axial sections referred
11
12
13 to indeterminate elasmosaurids have been recorded (Lazo and Chichowolski, 2003; O'Gorman et
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15 al., 2015). A partial skeleton including skull portions, recovered from lower Hauterivian-lower
16
17 Barremian beds of Germany, has been referred to an elasmosaurid (Sachs et al., 2015). However,
18
19
20 this shows a remarkable convergence of the palatal elements with the leptocleidid Nichollsaura
21
22 borealis Druckenmiller and Russell (2008). There is a gap of the elasmosaurid record during the
23
24 Barremian. Woolungasaurus glendowerensis Persson, 1960 is an incomplete postcranial skeleton
25
26
27 from the late Aptian of Australia. It was considered as an indeterminate elasmosaurid by Welles
28
29 (1962) and was later referred to the genus Styxosaurus (Sachs, 2004). We follow the criteria of
30
31
32 Welles (1962) due to the lack of genus-level diagnostic features. Callawayasaurus colombiensis
33
34 (Welles, 1962) is a fairly complete elasmosaurid from the Aptian of Colombia. This specimen
35
36 has unequivocal elasmosaurid traits in the skull and postcranial skeleton. Additional Albian
37
38
39 records are known from Australia (Kear, 2002), including cervical vertebrae with bilobed
40
41 articular faces typical of derived elasmosaurids. Albian indeterminate elasmosaurids are known
42
43 from Queensland, Australia (Kear, 2003). During the Upper Cretaceous, elasmosaurids became
44
45
46 cosmopolitan and have been found in all continents (Benson and Druckenmiller, 2014). All the
47
48 records commented above are summarized on Table 3.
49
50
51
52
53 Middle-to-Upper Jurassic records of Cryptoclididae. The presence of Cryptoclidids
54
55 plesiosaurians in the Oxfordian of Chile add new information to the known stratigraphic range of
56
57
58 the clade. Records of Laurasian cryptoclidids are well-documented from Middle-to-Upper
59
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2
3 Jurassic beds of England, particularly in Callovian units of Peterborough (Brown, 1981; Brown
4
5
6 and Cruickshank, 1994) and in Kimmeridgian beds of Dorset (Brown et al., 1986). Upper
7
8 Jurassic representatives have been found also in United States, from Oxfordian beds of the
9
10 Sundance Formation in Wyoming (O'Keefe and Wahl, 2003; O'Keefe and Street, 2009). A
11
12
13 remarkable diversity of highly derived cryptoclidids with very long necks was described from
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15 the Tithonian Agardhfjellet Formation in Svalbard, Norway (Knutsen et al., 2012a; b). A likely
16
17 cryptoclidid was also collected from Hauterivian beds of Chuvashia, Russia (Berezin, 2011:
18
19
20 originally regarded as an 'aristonectid'), representing the youngest known occurrence of
21
22 cryptoclidids (Benson and Druckenmiller, 2014).
23
24 This clade has been also recognized in the middle-to-late Oxfordian of Cuba, represented by
25
26
27 the species Vinialesaurus caroli (De la Torre and Rojas, 1949; Gasparini et al., 2001). Along the
28
29 Southern Hemisphere, the presence of cryptoclidids was reported from lower Callovian beds of
30
31
32 the Lajas Formation in Chacaico, Argentina. These strata are part of the Neuquén Basin
33
34 (Gasparini and Spalletti, 1993). Material referred to cryptoclidids comprise two isolated
35
36 vertebrae and an isolated radius assigned to cf. Muraenosaurus, genus then considered as an
37
38
39 elasmosaurid but currently included within the Cryptoclididae (Benson and Druckenmiller,
40
41 2014). As was mentioned before, the vertebrae could be referred to an elasmosaurid. Adding to
42
43 this, Gasparini and Spalletti (1993) also conferred a cervical vertebra and a radius to the genus
44
45
46 Cryptoclidus. The new record from Chile, although indeterminate to genus or species level, it
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48 complements the known distribution of the clade.
49
50
51
52
53 Middle-to-Upper Jurassic records of Pliosauridae. On the other hand, pliosaurids are well-
54
55 known in the Callovian, the Kimmeridgian and even in the Tithonian of England (Benson et al.,
56
57
58 2013) Other Kimmeridgian specimens are known in Norway (Knutsen et al., 2012b). There are
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3 few records of pliosaurids from the Oxfordian of Europe (Lomax, 2015; Maryanska, 1972; von
4
5
6 Huene, 1937); however, in a recent review of the specimens referred to the genus Peloneustes,
7
8 some of these records have been discarded (Ketchum, 2011) leaving the mention of a single
9
10 tooth from Poland as the only referable to a thalassophonean pliosaurid (Lomax, 2015). Thus, the
11
12
13 unique Oxfordian pliosaurid records known worldwide are represented by Thalassophonea indet.
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15 from Poland, Gallardosaurus iturraldei Gasparini, 2009, from Cuba, and MUHNCAL.20181
16
17 here studied.
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20 Younger pliosaurid records are known in South America during the Tithonian (Gasparini et
21
22 al., 1997; Gasparini and O'Gorman, 2014). Despite being scarce, the presence of pliosaurids in
23
24 the Oxfordian of Chile adds support for a full opening of the Caribbean Corridor during this
25
26
27 lapse.
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29
30
31
32 Paleobiogeography. Following Iturralde-Vinent (2005), the available stratigraphic information
33
34 from sedimentary rocks from the Caribbean area allows demonstrating that the Caribbean
35
36 Seaway (a marine corridor between the Thethys and Pacific) was completely functional at least
37
38
39 since the Oxfordian. Even more, the beginning of the opening occurred even before the
40
41 Oxfordian. The narrow phylogenetic relationships between the ammonoid assemblages from the
42
43 Tethys and those from the Neuquén Basin during the Bajocian suggest the existence of this
44
45
46 eventual connection ca. 7 Ma before the Oxfordian (Westermann and Riccardi, 1979). The
47
48 presence of S. prophetae (a Vinialesphinctinae) as well as cryptoclidid and pliosaurid
49
50 plesiosaurians now in the Tarapacá Basin, reinforces the presence of a common marine diversity
51
52
53 between northern Tethys, the Caribbean and the South American basins (at least Neuquén and
54
55 Tarapacá basins) during the Upper Jurassic. Paleogeographic occurrences of cryptoclidids during
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58 the Upper Jurassic-Lower Cretaceous have a mostly subtropical distribution along both
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3 hemispheres. The Oxfordian records from Wyoming (O'Keefe and Wahl, 2003a; O'Keefe and
4
5
6 Street, 2009; O'Keefe et al., 2011) could be the result of a marine corridor from the Caribbean
7
8 Seaway into the north. The unusual diversity of long-necked cryptoclidids from the Tithonian of
9
10 Norway (Knutsen et al., 2012a; b) includes the genera Djupedalia and Spitrasaurus, which bear
11
12
13 substantial anatomical differences compared to North American, Oxfordian forms, so far
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15 represented by the genera Pantosaurus and Tatenectes. Coeval records from Cuba includes a
16
17 single genus and species, Vinialesaurus caroli (De La Torre and Rojas, 1949; emend. Gasparini
18
19
20 et al., 2002). Regretfully, the Tithonian specimens from Norway lack their respective skulls,
21
22 while Oxfordian Cuban specimen lacks its postcranial skeleton, making impossible any
23
24 comparison. On the other hand, among Oxfordian North American specimens there are scarce
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26
27 cranial material of the species Tatenectes laramiensis, represented by a single tooth crown and a
28
29 fragmentary skull (O’Keefe and Wahl, 2003b). Again, no direct comparisons can be made
30
31
32 neither with the Norwegian, Tithonian specimens, nor with the holotype of V. caroli from the
33
34 Oxfordian of Cuba, since the latter does not preserves its posterior part of the skull. On the other
35
36 hand, V. caroli shows similarities with the skull of Cryptoclidus eurymerus from the Oxfordian
37
38
39 of England (Brown, 1981). Narrow morphological features of these skulls, as well as their coeval
40
41 occurrence, suggest a first stage of distribution between England, North America and the
42
43 Caribbean. The current record here studied complements the global picture of Middle and Upper
44
45
46 Jurassic plesiosaurian distribution, providing evidence of a widespread distribution of the three
47
48 clades, Cryptoclididae, Pliosauridae and Xenopsaria (including Elasmosauridae), with a common
49
50 presence in the European basins, the Caribbean, and those basins from southeastern Gondwana
51
52
53 (Fig. 11).
54
55
56
57
58 Evolutionary relevance of the Oxfordian plesiosaurian record from the Tarapacá Basin.
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2
3 Vertebral features of the Calama specimens, particularly those of MUHNCAL.20174, can be
4
5
6 compared with the genus Muraenosaurus Seeley, 1874, from the Callovian of England. Even in
7
8 its current taxonomic position within the Cryptoclididae as supported by recent phylogenetic
9
10 analyses (Benson and Druckenmiller, 2014), Muraenosaurus shows a remarkable convergence
11
12
13 with elasmosaurids. This genus possesses a skull with a more marked dorsoventral compression
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15 than that of Cryptoclidus; it also has an increased cervical count of 44 centra, contra ca. 30 in
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17 Cryptoclidus. Cervical vertebrae also show morphologies such neural arches higher than the
18
19
20 centrum, pre- and postzygapophyses extended beyond each articular facet, thin neural pedicels
21
22 and neural canali reduced compared to those of cryptoclidids. The "pectoral" vertebrae (meaning
23
24 cervical-dorsal transitional vertebrae) of Muraenosaurus do not differ from those of typical
25
26
27 elasmosaurids. Even more, remarkably similar vertebrae (however, isolated from other
28
29 postcranial remains) have been found in the Bajocian of Australia (Long and Cruickshank,
30
31
32 1998), the Callovian of Chacaico, Argentina (Gasparini and Spalletti, 1993) and now in the
33
34 Oxfordian of Chile. Such record suggests that similar animals could be present as early as during
35
36 the Middle Jurassic, but the absence of articulated remains precludes assessing if these
37
38
39 specimens are related or not to elasmosaurids. An exception is MUHNCAL.20174 which
40
41 preserves the cervical, transitional and dorsal vertebrae, plus all the morphological traits already
42
43 described, which allows us to refer it to the Elasmosauridae.
44
45
46 On the other hand, the presence of both elasmosaurids and cryptoclidids (at least based on the
47
48 studied vertebral morphotypes) was previously documented by Gasparini and Spalletti (1993) in
49
50 the Callovian of Chacaico, Argentina, being part of the Neuquén Basin. The presence of a
51
52
53 similar diversity in the Oxfordian of the Tarapacá Basin is plausible since both basins were open
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55 to the ancient Pacific and those conditions prevailed after the Callovian and at least until the
56
57
58 Kimmeridgian (Charrier et al., 2007). Even more, MUHNCAL.20176, here identified as an
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3 indeterminate xenopsarian, represents a specimen with features intermediate between
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6 cryptoclidids and elasmosaurids. It possesses humeri with articular heads remarkably similar to
7
8 those found among cryptoclidids, while the cervical vertebrae possess features such as the neural
9
10 spines rostrally recurved and the axially elongated pre- and postzygapophyses, both so far
11
12
13 observed in derived Late Cretaceous elasmosaurids. It must be stated that the elasmosaurid
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15 record during the Lower Cretaceous is still fragmentary and restricted to few localities
16
17 worldwide (Lazo and Chichowolski, 2003; O'Gorman et al., 2015; Sachs et al., 2015; Welles,
18
19
20 1962; Kear, 2002; 2003). This makes difficult to assess if such traits observed so far in
21
22 Oxfordian xenopsarians and in Late Cretaceous elasmosaurids, indeed occur among most
23
24 Cretaceous elasmosaurids. In any case, such recognized features suggest that MUHNCAL.
25
26
27 20176 could represent a very basal xenopsarian that still retains features present in its sister
28
29 taxon, the Cryptoclididae. Thus, the plesiosaurian assemblage in the Oxfordian of the Tarapacá
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31
32 Basin seems to include basal xenopsarians, derived xenopsarians (represented by elasmosaurids),
33
34 as well as their sister taxon, the Cryptoclidae. Such fauna suggests a closer temporal point of
35
36 divergence between the two main clades within Cryptoclidia (Xenopsaria and Cryptoclididae).
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38
39
40
41 Remarks on the previous vertebrate records from Cerritos Bayos.
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43 Biese (1957; 1961) mentioned the presence of vertebrates in Cerritos Bayos. In its general
44
45
46 stratigraphic profile of the locality, this author mentioned the presence of ichthyosaur vertebrae
47
48 in Loma Larga Norte and Sur, assigning it an Aalenian age based on invertebrates. In upper
49
50 levels assigned to the Bajocian, Biese (1961) indicated the presence of 'saurians' (Teleosaurus?)
51
52
53 and ichthyosaur remains in at least two different levels. In upper levels assigned by Biese to the
54
55 Callovian, this author recognized 1-10 m of concretionary limestones with a vertebrate
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57
58 assemblage, mentioning the presence of 'Ichthyosaurus quenstedti' (nomen dubium),
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3 'Plesiosaurus' (sensu lato), Megalosauridae, 'Pachycornius' (it should be Pachycormus), and
4
5
6 Lepidotus. Additionally, ichthyosaur remains were recognized in two upper levels of the
7
8 Callovian section. Finally, the upper levels assigned to the Oxfordian include 10-15 m of
9
10 'Aspidoceras limestones' (Calizas de Aspidoceras) with vertebrates referred to 'Ichthyosaurus ',
11
12
13 'Plesiosaurus', Pachycormus and Lepidotus. One of the levels here studied is recognized as
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15 equivalent to these Oxfordian limestones. They also include frequent fragmocones of
16
17 Euaspidoceras, as well as abundant vertebrate remains.
18
19
20 The vertebrate specimens mentioned by Biese (1957; 1961) were never figured and their
21
22 repository is currently unknown, making impossible their re-study. However, this research
23
24 confirms the presence of frequent bony elements referable to ichthyosaurs and plesiosaurians.
25
26
27 Also, we confirm the frequent presence of metriorhynchids (Soto-Acuña et al., 2015), which
28
29 could be confused by Biese (1961) with 'Teleosaurus'. So far, teleosaurids remain are until now
30
31
32 unknown in the Upper Jurassic of the Tarapacá Basin, and only indeterminate early
33
34 thalattosuchians are recorded in Sinemurian levels of Profeta Formation in Alto de Varas,
35
36 northern Chile (Chong and Gasparini, 1972; Gasparini, 1985). Biese (1957; 1961) also
37
38
39 mentioned remains referable to Megalosauridae. Regretfully, the material is currently lost, being
40
41 impossible to assess this record. Arratia (1996) and Ossa-Fuentes et al. (2015) confirmed the
42
43 presence of Pachycormiformes, as well as the genus Lepidotes in the Oxfordian of Cerritos
44
45
46 Bayos. More recently, Alarcón et al. (2015) added the presence of indeterminate pterosaurians in
47
48 Oxfordian levels of the same locality. Soto-Acuña et al. (2015) also described coeval, new
49
50 material of indeterminate metriorhynchids, while Otero et al. (2015) made the first preliminary
51
52
53 mention of elasmosaurids from the Oxfordian of Cerritos Bayos.
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3 Conclusions
4
5
6 The first plesiosaurian assemblage of Oxfordian age from South America is here described. Four
7
8
9 different morphotypes are recognized, being these referred to pliosaurids, cryptoclidids, as well
10
11 as xenopsarians. Among the latter, we recognize a basal, still indeterminate xenopsarian and an
12
13 indeterminate elasmosaurid. The articulated axial section referred to Elasmosauridae indet.
14
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15
16 includes pectoral and cervical centra remarkably similar to previous isolated records from the
17
18 Bajocian of Australia and the Callovian of Argentina, reinforcing their respective identifications
19
20
21 as elasmosaurids. This suggests that the clade Elasmosauridae could evolved from early
22
23 xenopsarians even before the Oxfordian, at some point during the Middle Jurassic. It also
24
25 supports a widespread presence of elasmosaurids along the Southern Hemisphere already during
26
27
28 the Middle and Upper Jurassic. This is consistent with phylogenetic analyses (Benson and
29
30 Druckenmiller, 2014) that suggest xenopsarians were separated from other cryptoclidians during
31
32 the same lapse.
33
34
35 The new record of pliosaurids in the Tarapacá Basin represents the first of Oxfordian age in
36
37 South America. Also, it is one of the fewest occurrences of pliosaurids in the Jurassic of South
38
39 America besides fragmentary postcranial material from the lower Callovian of Argentina and
40
41
42 several cranial specimens, including the Tithonian Pliosaurus patagonicus from Argentina.
43
44 Finally, this new pliosaurid record from Chile is the third Oxfordian pliosaurid known
45
46
47 worldwide, apart from Gallardosaurus iturraldei from Cuba and Thalassophonea indet. from
48
49 Poland.
50
51 The regional presence of cryptoclidids was previously reported from Callovian units of
52
53
54 Argentina. This new Oxfordian record verifies the continuity of the clade during the Upper
55
56 Jurassic, prior to the regression and end of the large Jurassic-Cretaceous basins that entered
57
58
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3 ancient South America from the Pacific side. Also, the common presence of cryptoclidids and
4
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6 pliosaurids in Oxfordian units of Cuba supports the fully establishment of the Caribbean
7
8 Corridor during this timespan, allowing the interchange of marine reptiles between the European
9
10 basins and the ancient southeastern Pacific and associated basins of South America.
11
12
13
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15 References
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17
18 ALARCÓN, J., SOTO-ACUÑA, S., OTERO, R.A., OSSA-FUENTES, L., & ROJAS, O., 2015. Primer
19
20
21 registro de pterosaurios en el Jurásico Superior (Oxfordiano) de la Formación Cerritos
22
23 Bayos, Calama, Región de Antofagasta. XIV Congreso Geológico de Chile, Actas
24
25 Volumen III, Área Temática 5, Bioestratigrafía y Paleontología Andina, pp. 698-701.
26
27
28 ALBRIGHT, L.B., GILLETTE, D.D., & TITUS, A.L., 2007. Plesiosaurs from the Upper Cretaceous
29
30 (Cenomanian–Turonian) Tropic Shale of Southern Utah, Part 1: new records of the
31
32 pliosaur Brachauchenius Lucasi. Journal of Vertebrate Paleontology 27, 31–40.
33
34
35 ANDREWS, C.W., 1909. On some new Plesiosauria from the Oxford Clay of Peterborough.
36
37 Annals And Magazine of Natural History 4, 418-429.
38
39 ANDREWS, C.W. 1910. A Descriptive Catalogue of the Marine Reptiles of the Oxford Clay, Part
40
41
42 I. British Museum (Natural History), London, 205 pp.
43
44 ARRATIA, G., 1996. The Jurassic and the early history of teleosts. In Mesozoic Fishes –
45
46
47 Systematic and Paleoecology, ARRATIA, G. & VIOHL, G., eds, Verlag, München, 243‒260.
48
49 BENSON, R.B.J., & DRUCKENMILLER, P.S., 2014. Faunal turnover of marine tetrapods during
50
51 the Jurassic–Cretaceous transition. Biological Reviews 89, 1–23.
52
53
54
55
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57
58
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60 32
URL: http://mc.manuscriptcentral.com/talc E-mail: [email protected]
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3 BENSON, R.B. J., BATES, K.T., JOHNSON, M.R., & WITHERS, P.J., 2011. Cranial anatomy of
4
5
6 Thalassiodracon hawkinsii (Reptilia, Plesiosauria) from the Early Jurassic of Somerset,
7
8 United Kingdom. Journal of Vertebrate Paleontology 31, 562‒574.
9
10 BENSON, R.B.J., EVANS, M., SMITH, A.S., SASSOON, J., MOORE-FAYE, S., KETCHUM, H.F., &
11
12
13 FORREST, R., 2013. A Giant Pliosaurid Skull from the Late Jurassic of England. PlosOne
14 For Peer Review Only
15 8, e65989. 34 p.
16
17 BEREZIN, A.Y., 2011. A New Plesiosaur of the Family Aristonectidae from the Early Cretaceous
18
19
20 of the Center of the Russian Platform. Paleontological Journal 45, 648–660.
21
22 BIESE, W., 1957. Der Jura von Cerritos Bayos-Calama, República de Chile, Provincia de
23
24 Antofagasta. Geologie Jahrbuch 72, 439‒494.
25
26
27 BIESE, W., 1961. El Jurásico de Cerritos Bayos. Instituto de Geología, Universidad de Chile,
28
29 Santiago, Publication 19. 61 pp.
30
31
32 BROWN, D.S., 1981. The English Upper Jurassic Plesiosauroidea (Reptilia) and review of the
33
34 phylogeny and classification of the Plesiosauria. Bulletin of the British Museum (Natural
35
36 History), Geology 4, 225–234.
37
38
39 BROWN, D., & CRUICKSHANK, A.R.I., 1994. The skull of the Callovian plesiosaur Cryptoclidus
40
41 eurymerus, and the sauropterygian cheek. Palaeontology 37, 941–953.
42
43 BROWN, D.S., MILNER, A.C., & TAYLOR, M.A., 1986. New material of the plesiosaur
44
45
46 Kimmerosaurus langhami from the Kimmeridge Clay of Dorset. Bulletin of the British
47
48 Museum Natural History, Geology Series 40, 225–234.
49
50
51 CHARRIER, R., PINTO, L., & RODRÍGUEZ, M.P., 2007. Tectonostratigraphic evolution of the
52
53 Andean Orogen in Chile. In The Geology of Chile. MORENO, T. & GIBBONS, W., eds, The
54
55 Geological Society, London, 21–114.
56
57
58
59
60 33
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Alcheringa Page 34 of 57
1
2
3 COPE, E.D., 1869. On the reptilian orders Pythonomorpha and Streptosauria. Proceedings of the
4
5
6 Boston Society of Natural History 12, 250‒266.
7
8 CRUICKSHANK, A.R.I.,1994. A juvenile plesiosaur (Plesiosauria: Reptilia) from the Lower Lias
9
10 (Hettangian: Lower Jurassic) of Lyme Regis, England: a pliosauroid-plesiosauroid
11
12
13 intermediate?. Zoological Journal of the Linnean Society 112, 151–178.
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15 CRUICKSHANK A.R.I., & FORDYCE R.E., 2002. A new marine reptile (Sauropterygia) from New
16
17 Zealand: further evidence for a Late Cretaceous austral radiation of cryptocleidid
18
19
20 plesiosaurs. Palaeontology 45, 557‒575.
21
22 DE BLAINVILLE, H.M.D., 1835. Description de quelques espèces de reptiles de la Californie
23
24 précédé de l’analyse d’un système général d’herpétologie et d’amphibiologie. Nouvelles
25
26
27 Annales du Muséum d’Histoire Naturelle de Paris, Série 3, 4, 233–296.
28
29 DE LA TORRE, R. & ROJAS, L.E., 1949. Una nueva especie y dos subespecies de ichthyosauria
30
31
32 del Jurásico de Viñales, Cuba. Memorias de la Sociedad Cubana de Historia Natural
33
34 ‘Felipe Poey’ 19, 197–202.
35
36 DRUCKENMILLER, P.A. & RUSSELL, A.P., 2008. Skeletal anatomy of an exceptionally complete
37
38
39 specimen of a new genus of plesiosaur from the Early Cretaceous (early Albian) of
40
41 northeastern Alberta, Canada. Palaeontographica Abteilung A 283,1‒33.
42
43 ETHERIDGE, R., 1904. A second sauropterygian converted into opal from the Upper Cretaceous
44
45
46 of White Cliffs, New South Wales, with indications of ichthyopterygians at the same
47
48 locality. Records of the Australian Museum 5, 306‒316.
49
50
51 GASPARINI, Z., & O'GORMAN, J.P., 2014. A new species of Pliosaurus (Sauropterygia,
52
53 Plesiosauria) from the Upper Jurassic of northwestern Patagonia, Argentina. Ameghiniana
54
55 51, 269–283.
56
57
58
59
60 34
URL: http://mc.manuscriptcentral.com/talc E-mail: [email protected]
Page 35 of 57 Alcheringa
1
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3 GASPARINI, Z., & SPALLETTI, L., 1993. First Callovian plesiosaurs from the Neuquen Basin,
4
5
6 Argentina. Ameghiniana 30, 245–254.
7
8 GASPARINI, Z., BARDET, N., & ITURRALDE-VINENT, M.A., 2001. A new cryptoclidid plesiosaur
9
10 from the Oxfordian (Late Jurassic) of Cuba. Geobios 35, 201–211.
11
12
13 GASPARINI, Z., BARDET, N., MARTIN, J.E., & FERNÁNDEZ, M., 2003. The elasmosaurid
14 For Peer Review Only
15 plesiosaur Aristonectes Cabrera from the latest Cretaceous of South America and
16
17 Antarctica. Journal of Vertebrate Paleontology 23, 104–115.
18
19
20 GASPARINI, Z., 2009. A new Oxfordian pliosaurid (Plesiosauria, Pliosauridae) in the Caribbean
21
22 Seaway. Palaeontology 52, 661‒669.
23
24 GYGI, R.A. & HILLEBRANDT, A. VON, 1991. Ammonites (mainly Gregoryceras) of the
25
26
27 Oxfordian (Late Jurassic) in northern Chile and time-correlation with Europe. Mémoires
28
29 Suisses de Paléontologie 113, 135‒185.
30
31
32 HAMPE, O. 2013. The forgotten remains of a leptocleidid plesiosaur (Sauropterygia,
33
34 Plesiosauroidea) from the Early Cretaceous of Gronau (Münsterland, Westphalia,
35
36 Germany). Palaontologische Zeitschrift 87, 473‒491.
37
38
39 HUENE, F. VON, 1937. Plesiosaurier im kurländischen Jura. Zentralblatt für Mineralogie
40
41 Abteilung B, 1, 50–52.
42
43 ITURRALDE-VINENT, M.A., 2005. La Paleogeografía del Caribe y sus implicaciones para la
44
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46 biogeografía histórica. Revista del Jardín Botánico Nacional 25–26, 49–78.
47
48 KEAR, B.P., 2002. Reassessment of the Early Cretaceous plesiosaur Cimoliasaurus maccoyi
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50 Etheridge, R. 1904 (Reptilia, Sauropterygia) from White Cliffs, New South Wales.
51
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53 Australian Journal of Zoology 50, 671–685.
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55 KEAR, B.P., 2003. Cretaceous marine reptiles of Australia: a review of taxonomy and
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58 distribution. Cretaceous Research 24, 277–303.
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3 KETCHUM, H.F. & BENSON, R.B., 2010. Global interrelationships of Plesiosauria (Reptilia,
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6 Sauropterygia) and the pivotal role of taxon sampling in determining the outcome of
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8 phylogenetic analyses. Biological Reviews 85, 361–392.
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10 KNUTSEN, E.M., DRUCKENMILLER, P.S. & HURUM, J.H., 2012a. Two new species of long-
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13 necked plesiosaurians (Reptilia: Sauropterygia) from the Upper Jurassic (Middle Volgian)
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15 Agardhfjellet Formation of central Spitsbergen. Norwegian Journal of Geology 92, 187–
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17 212.
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20 KNUTSEN, E.M., DRUCKENMILLER, P.S., & HURUM, J.H., 2012b. A new species of Pliosaurus
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22 (Sauropterygia: Plesiosauria) from the Middle Volgian of central Spitsbergen, Norway.
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24 Norwegian Journal of Geology 92, 235–258.
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27 LAZO, D. & CHICHOWOLSKI, M. 2003. First Plesiosaur Remains from the Lower Cretaceous of
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29 the Neuquén Basin, Argentina. Journal of Paleontology 77, 784‒789.
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32 LOMAX, D.R., 2015. The first plesiosaurian (Sauropterygia, Pliosauridae) remains described
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34 from the Jurassic of Poland. Palaeontologia Electronica 18.2.29A, 1-8
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36 LONG, D.J. & CRUICKSHANK, A.R.I., 1998. Further records of plesiosaurian reptiles of Jurassic
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39 and Cretaceous age from Western Australia. Records of the Western Australian Museum
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41 19, 47‒55.
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43 MARYANSKA, T., 1972. Aberrant pliosaurs from the Oxfordian of Poland. Prace Museum Ziemi
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46 20, 201–206.
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48 MELÉNDEZ, G., & MYCZYNSKI, R., 1987. Sobre la posición sistemática de los ammonites del
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50 Oxfordiense de los Andes Chilenos (Cordillera Domeyko, Chile, Provincia Andina).
51
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53 Geogaceta 2, 12–14.
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55 O'GORMAN, J.P., SALGADO, L., OLIVERO, E.B. & MARENSSI, S., 2015. Vegasaurus molyi gen.
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58 et sp. nov. (Plesiosauria, Elasmosauridae) from the Cape Lamb Member (lower
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3 Maastrichtian) of the Snow Hill Island Formation, Vega Island, Antarctica, and remarks on
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6 Weddellian Elasmosauridae. Journal of Vertebrate Paleontology e931285. 21 pp.
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8 O'GORMAN, J.P., LAZO, D.G., LUCI, L., CATALDO, C.S., SCHWARZ, E., LESCANO, M., &
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10 AGUIRRE-URRETA, M.B., 2015. New plesiosaur records from the Lower Cretaceous of the
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13 Neuquén Basin, west-central Argentina, with an updated picture of occurrences and facies
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15 relationships. Cretaceous Research 56, 372-387.
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17 O'KEEFE, F.R., 2001. A cladistic analysis and taxonomic revision of the Plesiosauria (Reptilia:
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20 Sauropterygia). Acta Zoologica Fennica 213, 1–63.
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22 O'KEEFE, F.R. & WAHL, W., 2003a. Current taxonomic status of the plesiosaur Pantosaurus
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24 striatus from the Upper Jurassic Sundance Formation, Wyoming. Paludicola 4, 37–46.
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27 O’KEEFE, F. R. & WAHL W., 2003b. Preliminary report on the osteology and relationships of a
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29 new aberrant cryptocleidoid plesiosaur from the Sundance Formation, Wyoming.
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32 Paludicola 4, 48–68.
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34 O'KEEFE, F.R., & STREET, H., 2009. Osteology of the cryptocleidoid plesiosaur Tatenectes
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36 laramiensis, with comments on the taxonomic status of the Cimoliasauridae. Journal of
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39 Vertebrate Paleontology 29, 48–57.
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41 O'KEEFE, F.R., STREET, H.P., WILHELM, B.C., RICHARDS, C.D. & ZHU, H., 2011. A new
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43 skeleton of the cryptoclidid plesiosaur Tatenectes laramiensis reveals a novel body shape
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46 among plesiosaurs. Journal of Vertebrate Paleontology 31, 330–339.
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48 OSBORN, H.F., 1903. The reptilian subclasses Diapsida and Synapsida and the early history of
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50 the Diaptosauria. Memoirs of the American Museum of Natural History 1, 451–507.
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53 OSSA-FUENTES, L., SOTO-ACUÑA, S., OTERO, R.A., ALARCÓN, J. & ROJAS, O., 2015. Nuevos
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55 ejemplares de peces óseos (Osteichthyes: Actinopterygii) del Jurásico Superior de Cerritos
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3 Bayos, Calama, norte de Chile. XIV Congreso Geológico de Chile, Actas Volumen III,
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6 Área Temática 5, Bioestratigrafía y Paleontología Andina, pp. 694-697.
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8 OTERO, R.A., 2016. Taxonomic reassessment of Hydralmosaurus as Styxosaurus: new insights
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10 on the elasmosaurid neck evolution throughout the Cretaceous. PeerJ 4:e1777. 60 pp.
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13 OTERO, R.A., SOTO-ACUÑA, S. & RUBILAR-ROGERS, D., 2012. A postcranial skeleton of an
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15 elasmosaurid plesiosaur from the Maastrichtian of central Chile, with comments on the
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17 affinities of Late Cretaceous plesiosauroids from the Weddellian Biogeographic Province.
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20 Cretaceous Research 37, 89‒99.
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22 OTERO, R.A., SOTO-ACUÑA, S., O’KEEFE, F.R., O’GORMAN, J.P., STINNESBECK, W., SUÁREZ,
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24 M.E., RUBILAR-ROGERS, D., SALAZAR, C. & QUINZIO, L.A., 2014. Aristonectes
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27 quiriquinensis sp. nov.; a new highly derived elasmosaurid from the upper Maastrichtian of
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29 central Chile. Journal of Vertebrate Paleontology 34, 100-125.
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32 OTERO, R.A., SOTO-ACUÑA, S., ALARCÓN, J., OSSA-FUENTES, L. & ROJAS, O., 2015. Los
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34 elasmosáuridos más antiguos hasta ahora conocidos: primer registro en el Oxfordiano de
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36 Gondwana. XIV Congreso Geológico de Chile, Actas Volumen III, Área Temática 5,
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39 Bioestratigrafía y Paleontología Andina, pp. 683-685.
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41 OWEN, R., 1841. Odontography, Part II. Hippolyte Baillière. 655 pp.
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43 OWEN, R., 1860. On the orders of fossil and recent Reptilia and their distribution in time. Report
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46 of the British Association for the Advancement of Science 29, 153–166.
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48 PARENT, H., SCHWEIGERT, G. & MELÉNDEZ, G., 2006. Oxfordian perisphinctid ammonites
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50 from Chacay Melehue, Argentina. Paläontologische Zeitschrift 80, 307‒324.
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53 PERSSON, O., 1960. Lower Cretaceous plesiosaurians (Reptilia) from Australia. Lunds
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55 Universitets Årsskrift 56, 1‒23.
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3 SACHS, S., 2004. Redescription of Woolungasaurus glendowerensis (Plesiosauria:
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6 Elasmosauridae) from the Lower Cretaceous of Northeast Queensland. Memoirs of the
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8 Queensland Museum 49, 713‒731.
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10 SACHS, S., HORNUNG J. J., WOHLSEIN, P. & KEAR, B.P., 2015. A new basal elasmosaurid
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13 skeleton with joint pathologies from the Lower Cretaceous of Germany. European
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15 Association of Vertebrate Paleontologists, XIII Annual Meeting, Opole, Poland. p. 131.
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17 SACHS, S., HORNUNG, J.J. AND KEAR, B., 2016. Reappraisal of Europe's most complete Early
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20 Cretaceous plesiosaurian: Brancasaurus brancai Wegner, 1914 from the "Wealden facies"
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22 of Germany. PeerJ 4, e2813. 79 p.
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24 SATO, T. & WU, X-.C., 2008. A new Jurassic pliosaur from Melville Island, Canadian Arctic
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27 Archipelago. Canadian Journal of Earth Sciences 45, 303–320.
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29 SAUVAGE, H.E., 1879. Prodrome des Plésiosauriens et des Elasmosauriens dew formations
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32 Jurassique supérieures de Bologne-sur-Mer. Annales des Sciences Naturelles du París 8,
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34 1‒38.
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36 SEELEY, H.G., 1874. Note on some of the generid modifications of the plesiosaurian pectoral
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39 arch. Quarterly Journal of the Geological Society (London) 30, 436‒449.
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41 SENNIKOV, A.G. & ARKHANGELSKY, M.S., 2010. On a Typical Jurassic Sauropterygian from
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43 the Upper Triassic of Wilczek Land (Franz Josef Land, Arctic Russia). Paleontological
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46 Journal 44, 567–572.
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48 SMITH, A.S., 2007. Anatomy and systematics of the Rhomaleosauridae (Sauropterygia,
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50 Plesiosauria). Ph.D. thesis, University College Dublin. 165 p.
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53 SMITH, A.S., 2015. Reassessment of ‘Plesiosaurus’ megacephalus (Sauropterygia: Plesiosauria)
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55 from the Triassic-Jurassic boundary, UK. Palaeontologia Electronica 18.1.20A, 1–19.
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3 SMITH, A.S. & VINCENT, P., 2010. A new genus of pliosaur (Reptilia: Sauropterygia) from the
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6 Lower Jurassic of Holzmaden, Germany. Palaeontology 53, 1049–1063.
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8 SOTO-ACUÑA, S., OTERO, R.A., ALARCÓN, J., OSSA-FUENTES, L. & ROJAS, O., 2015.
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10 Presencia de cocodrilos marinos (Thalattosuchia: Metriorhynchidae) en la Formación
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13 Cerritos Bayos (Oxfordiano), Cuenca de Tarapacá, Región de Antofagasta. XIV Congreso
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15 Geológico de Chile, Actas Volumen III, Área Temática 5, Bioestratigrafía y Paleontología
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17 Andina, pp. 690-693.
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20 STEINMANN, G., 1881. Zur kenntnis der Jura- und Kreideformation von Caracoles (Bolivia).
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22 Neues Jahrbuch für Mineralogie Geologie und Paleontologie 1, 239‒302.
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24 TARLO, L.B., 1959. Pliosaurus brachyspodylus (Owen) from the Kimmeridge Clay.
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27 Palaeontology 1, 283‒291.
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29 VINCENT, P., 2011. A re-examination of Hauffiosaurus zanoni, a pliosauroid from the Toarcian
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32 (Early Jurassic) of Germany. Journal of Vertebrate Paleontology 31, 340‒351.
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34 VINCENT, P. & BENSON, R.B.J., 2012. Anningasaura, a basal plesiosaurian (Reptilia,
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36 Plesiosauria) from the Lower Jurassic of Lyme Regis, United Kingdom. Journal of
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39 Vertebrate Paleontology 32, 1049–1063.
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41 WEGNER, T., 1914. Brancasaurus brancai n. g., n. sp., ein Elasmosauride aus dem Wealden
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43 Westfalens. In Branca Festschrift. SCHOENDORF, F., ed, Stuttgart: Gebrüder Borntraeger,
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46 234‒305.
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48 WELLES, S.P., 1943. Elasmosaurid plesiosaurs with description of new material from California
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50 and Colorado. Memoirs of the University of California 13, 125–254.
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53 WELLES, S.P., 1952. A review of the North American Cretaceous elasmosaurs. University of
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55 California Publications in Geological Sciences 29, 47–144.
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3 WELLES, S.P., 1962. A new species of elasmosaur from the Aptian of Colombia and a review of
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6 the Cretaceous plesiosaurs. University of California, Publications in Geological Sciences
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8 44, 1–96.
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10 WESTERMANN, G.E.G. & RICCARDI, R., 1979. Middle Jurassic ammonoid fauna and
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13 biochronology of the Argentinean-Chilean Andes. Part II: Bajocian Stephanocerataceae.
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15 Paleontographica Abteilung A 164, 85–188.
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17 WILLISTON, S.W., 1925. The osteology of the reptiles. Harvard University Press. 300 p.
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3 FIGURE CAPTIONS
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7 Fig. 1. Map of west Calama, northern Chile, indicating the localities of the Cerritos Bayos
8 Formation where the studied plesiosaurian specimens were collected. [planned for page
9 width]
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11 Fig. 2. A, General stratigraphic section of the Cerritos Bayos Formation, indicating the
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13 approximate stratigraphic provenance of the studied specimens, as well as other
14 associated vertebrates; B-D, Assorted ammonoid specimens from the studied localities; B,
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15 Subvinialesphinctes prophetae (Gygi and Hillebrandt, 1991). Fragmocone. Biese 3
16 locality; C, S. prophetae. Cerro Campamento; D, S. prophetae. Quebrada Campamento;
17
18 E, Euaspidoceras sp. Cerro Campamento. Scale bar equals = 10 mm. [planned for page
19 width]
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21 Fig. 3. Pliosauridae indet. MUHNCAL.20181. A, Left dentary in labio-occlusal section; B,
22 Scheme of the same. Anatomical abbreviations: aft, alveoli of functional teeth; cf,
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24 coronoid facet; d, dentary; lin, labial inflection; lpd, lingual process of the dentary; tcr,
25 tooth crown. Scale bar equals 50 mm.
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27 Fig. 4. Cryptoclididae indet. A, MUHNCAL.20175. Dorsal vertebra in articular view, with
28 sandstone matrix digitally faded; B, Scheme of the same; C, Pectoral vertebra in articular
29 view (opposite side of the same block), with sandstone matrix digitally faded; D, Scheme
30
31 of the same; E, MUHNCAL.20172. Isolated dorsal centrum; F. MUHNCAL.20146.
32 Fragment of dentary. Anatomical abbreviations: if, internal facet of the
33 prezygapophyses; nc, neural canal; np, neural pedicels; ns, neural spine; pg, posterior
34 groove; pf, posterior facet; pdp, paradental plate; prz, prezygapophysis; tp, transverse
35 process. Scale bar equals 50 mm. except C, equals 10 mm. [planned to page width]
36
37 Fig. 5. A. Xenopsaria indet. MUHNCAL.20176. Schematics of the bone remains in
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39 anatomical position. Scale bar equals 50 cm. B-D. Detail of each block preserving axial
40 elements. Scale bar equals 10 cm. Anatomical abbreviations: cr, cervical ribs; cv,
41 cervical vertebrae; dr, dorsal ribs; dv, dorsal vertebrae; pv, pectoral vertebrae; trr,
42 transitional ribs. [planned for page width]
43
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45 Fig. 6. Xenopsaria indet. MUHNCAL.20176. A. anteriormost preserved block (mirrored for
46 better view), and following block with neck elements. B. anatomical interpretation of the
47 preserved elements. Posterior cervical vertebrae of cryptoclidids and leptocleidids, for
48 comparison. C. Cryptoclidus eurymerus (Phillips, 1871), left view. Modified from Brown
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50 (1981:fig. 8b). D. Muraenosaurus leedsi Seeley, 1874 (=Muraenosaurus 'durobrivensis'),
51 left view. Modified from Andrews (1910:fig. 51). E. Brancasaurus brancai Wegner,
52 1914, right view (mirrored for comparison). Modified from Wegner (1914:plateVII, 2a).
53 F. Nichollsaura borealis Druckenmiller and Russell, 2008, right view (mirrored for
54 comparison). Modified from Druckenmiller and Russell (2008:fig. 11). Anatomical
55 abbreviations: ns, neural spines; cc, cervical centra; d1, first dorsal centrum; dv, dorsal
56
57 vertebra; pv; pectoral vertebrae; poz, postzygapophyses; prz, prezygapophyses; trp,
58 transverse processes. Scale bar equals 100 mm. [planned for page width]
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4 Fig. 7. Xenopsaria indet. MUHNCAL.20176. A. Cast of the left humerus in ventral view.
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6 B. Cast of the right humerus in oblique view. C. Humeral ontogenetic series of
7 Cryptoclidus eurymerus. From Caldwell (1997:fig. 5A-E). Dorsal views of several
8 cryptoclidids. D. Cryptoclidus eurymerus. E. Cryptoclidus richardsoni. F.
9 Muraenosaurus leedsi. G. Microcleidus beloclis. H. Tricleidus seeleyi. I. Colymbosaurus
10
11 trochanterius. C-H, from Brown (1981: fig. 44). J. Spitrasaurus wensaasi, ventral view.
12 Modified from Knutsen et al. (2012: fig. 11). Humeral morphologies among
13 elasmosaurids. K. Callawayasaurus colombiensis, left humerus in dorsal view. From
14 Welles (1962: fig .6). L. Thalassomedon haningtoni, right humerus in dorsal view
For Peer Review Only
15 (mirrored). From Welles (1952: fig. 17). M. Styxosaurus browni, left humerus in dorsal
16 view. From Welles (1952: fig. 7). N. Hydrotherosaurus alexandrae, right humerus in
17
18 dorsal view (mirrored). From Welles (1952: fig 20). Scale bar in A, B equals 100 mm; C,
19 50 mm; D-N, 100 mm. [planned for page width]
20
21 Fig. 8. Elasmosauridae indet. MUHNCAL.20174.Cervical-dorsal axial section. A. Left
22 lateral view. B. Schematics of the previous. C. Ventral view. D. Right lateral view.
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24 Anatomical abbreviations: lcv, last cervical vertebra; r-tp, rib-transverse process mixed
25 facet; d1, first dorsal vertebra; pv, pectoral vertebrae. Scale bar equals 100 mm. [planned
26 to page width]
27
28 Fig. 9. Elasmosauridae indet. MUHNCAL.20174. A-E. Five anteriormost cervical
29 vertebrae in anterior articular view. The sixth cervical vertebra remains articulated to the
30
31 fifth, making impossible its anterior view. F. Detail of the neural spine of the third
32 preserved cervical vertebra. G. Detail of the neural spine of the third preserved cervical
33 vertebra. H-M. Anterior view of the four pectoral vertebrae preserved. A12-A13. Anterior
34 view of the two dorsal vertebrae preserved. Anatomical abbreviations: nc, neural canal;
35 prz, prezygapophyses. A-E, H-M, scale bar = 100 mm; F, G, scale bar equals 10 mm.
36
37 [planned to page width]
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39 Fig. 10. Comparison of MUHNCAL.20181 (Pliosauridae indet). with other pliosaurid
40 genera and species. Schemes not to scale. [planned to page width]
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42 Fig. 11. Middle-to-Upper Jurassic tectonic plate map showing the known records of
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44 cyptoclidids, pliosaurids and elasmosaurids, including the new material here studied. Plate
45 tectonic map modified from ODSN Plate Tectonic Reconstruction Service, University of
46 Bremen, Germany (http://www.odsn.de/odsn/services/paleomap/paleomap.html).
47 [planned to page width]
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3 Table 1: Vertebral measurements of the plesiosaurian MUHNCAL.20174 from Cerritos
4
5 Bayos.
6
7 anatomical position length height breadth VLI HI BI
8 cervical 59,15 49,66 78 92,6680244 83,956044 131,868132
9
10 cervical 67,85 57,47 77,53 100,518519 84,7015475 114,266765
11 cervical 62,74 56,4 82,21 90,527379 89,894804 131,032834
12 cervical 62,76 54,76 74,28 97,2721637 87,2530274 118,355641
13 pectoral 64,03 58,25 72,51 97,9351484 90,9729814 113,243792
14 For Peer Review Only
15 cervical 65,66 56,04 73,98 100,999846 85,3487664 112,671337
16 cervical 68,01 55,84 75,74 103,374373 82,1055727 111,365976
17 pectoral 68,98 55,43 77,37 103,885542 80,3566251 112,162946
18
19 pectoral — 58,18 72 — — —
20 dorsal 66,31 60,13 70,28 101,694655 90,6801387 105,987031
21 dorsal 66,67 62,98 71,3 99,2999702 94,4652767 106,944653
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3 Table 2: Comparison of cervical centrum breadth with their respective combined
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5 prezygapophyseal breadth (CPB).
6 taxon collection number age and locality cervical centrum combined CPB/CB references
7 position breadth prezygapo-
8 (mm) physeal
breadth
9 (CPB)
Cryptoclidus
10 eurymerus HMG V 1104 Oxfordian, UK 25 52 34 0,65 Brown (1981)
11 Brancasaurus Hauterivian,
brancai Germany
12 GWWU A3.B4 19 38 24 0,63 Wegner (1914)
13
14 Callawayasaurus UCMP 38349 Aptian, Colombia 51 107 54 0,5 Welles (1962)
15 colombiensis NHMUK 2863 Callovian, UK 35 42* 21* 0,5 Andrews (1910)
16 Muraenosaurus For Peer Review Only
leedsi
17 ? (among
18
19 Elasmosauridae MUHNCAL.20174 middle to upper posterior 82 25 0,3 this study
indet. Oxfordian most
20 centra)
21 upper Campanian,
Western Interior 25
22 Styxosaurus sp. AMNH 1495 Seaway 60 20 0,33 Welles (1943);
23 Otero (2016)
24
25 lower
Maastrichtian,
26 Vegasaurus molyi MLP-93-1-5-1 Antarctica 10 38 14 0,38 O'Gorman et al.
27 (2015)
28
29 Aristonectes SGO.PV.260 upper 19? 88 24 0,27 Otero et al. (2012)
30 quiriquinensis Maastrichtian,
31 (referred) central Chile
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3 Table 3: Summary of the Jurassic-Lower Cretaceous occurrences of elasmosaurid
4
5 plesiosaurs, with comments on their previous taxonomic determinations.
6 former discussed
taxonomic taxonomical
7 Collection number determination determination preserved age litostratigraphic locality references
8 elements unit
9 WAM.86.10.707 Elasmosauridae — isolated pectoral Bajocian Colalura Geraldton, Long and Cruickshank,
10 indet. part of the vertebra Sandstone Australia 1998
11 MOZ.6003, 6004 cf. material likely cervical Callovian Lajas Formation Chacaico, Gasparini and Spalletti,
12 and 6006 Muraenosaurus: belongs to an vertebrae Argentina 1993
cf. Cryptoclidus indeterminate
13 Elasmosauridae
14 MUHNCAL.20174 Elasmosauridae — cervical-dorsal Oxfordian Cerritos Bayos Calama, Otero et al., 2015
indet. axial section Formation Chile
15 previously For Peer Review Only
16 GWWU-A3.B4 Brancasaurus referred referred fairly complete Berriasian Osterwald- Gronau, Wegner, 1914, Hampe,
17 brancai to the skeleton Schichten Germany 2013;
18 (Plesiosauria: leptocleidid Formation
Elasmosauridae) Gronausaurus
19 wegneri
previously
20 GWWU-A3 B2 Brancasaurus referred to the incomplete Berriasian Osterwald- Gronau, Benson and
21 brancai Elasmosauridae; postcranial Schichten Germany Druckenmiller, 2014;
22 currently skeleton Formation Hampe, 2013; Sachs et
considered a al., 2016
23 leptocleidid upper
Valanginian
24 MOZ-PV 6890, Elasmosauridae — several axial -lower Agrio Formation Neuquén, Lazo and Chichowolski,
25 6892, 6893, 6894, indet. sections Hauterivian not detailed Argentina 2003; O'Gorman et al.,
26 6991 and 6992 2015
27 Elasmosauridae Leptocledidae? skull parts and lower Lower
28 housed at incomplete Hauterivian- Saxony, Sachs et al., 2015
Niedersächsisches indet. indet. postcranial lower Germany
Landesmuseum, skeleton Barremian
29 Hannover
30
31 QM F3567 Woolungasaurus Elasmosauridae incomplete upper Wallumbilla Queensland, Persson, 1960; Kear,
glendowerensis; indet. postcranial Aptian Formation Australia 2003; Sachs, 2004
Styxosaurus skeleton
glendowerensis
32 NMV2572, NMV Elasmosauridae — cervical centra Albian uncertain Queensland, Kear, 2003
33 P22548 indet. Australia
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28 Fig. 1. Map of west Calama, northern Chile, indicating the localities of the Cerritos Bayos Formation where
29 the studied plesiosaurian specimens were collected. [planned for page width]
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38 Fig. 2. A, General stratigraphic section of the Cerritos Bayos Formation, indicating the approximate
stratigraphic provenance of the studied specimens, as well as other associated vertebrates; B-D, Assorted
39 ammonoid specimens from the studied localities; B, Subvinialesphinctes prophetae (Gygi and Hillebrandt,
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41 1991). Fragmocone. Biese 3 locality; C, S. prophetae. Cerro Campamento; D, S. prophetae. Quebrada
42 Campamento; E, Euaspidoceras sp. Cerro Campamento. Scale bar equals = 10 mm. [planned for page
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36 Fig. 3. Pliosauridae indet. MUHNCAL.20181. A, Left dentary in labio-occlusal section; B, Scheme of the
37 same. Anatomical abbreviations: aft, alveoli of functional teeth; cf, coronoid facet; d, dentary; lin, labial
38 inflection; lpd, lingual process of the dentary; tcr, tooth crown. Scale bar equals 50 mm.
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Plesiosaurios North of Chile
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