Comparative Anatomy - public.wsu.edu

Comparative Anatomy Comparative Anatomy

Changes in vertebrate body with the passage of time Changes in vertebrate body with the passage of time
SIGNIFICANCE OF THOSE CHANGES
SIGNIFICANCE OF THOSE CHANGES
a) Functional Significance
a) Functional Significance Biomechanics
Cursorial
Water Î Land

Comparative Anatomy Skeletal System

Changes in vertebrate body with the passage of time

SIGNIFICANCE OF THOSE CHANGES

b) Evolutionary significance Cranial Post-cranial

Remodel Preadaptation

Splanchnocranium, Axial Appendicular
Dermatocranium,
Sarcopterygians Chondrocranium

Notochord, limbs, girdles

Vertebral column

Early tetrapods

Chondrocranium Remodeling

Splanchnocranium Triple
evolutionary
sources

Dermatocranium

1

Getting a Head

Goethe

Oken/Owen

Richard Owen

Chondrocranium

trabeculae parachordals occipitals sensory capsules

CHONDROCRANIUM

sphenoids ethmoids occipitals otic, optic, nasal

CENTERS OF OSSIFICATION

CHONDROCRANIUM SPLANCHNOCRANIUM

General Functions (=Visceral Skeleton)

1)Adult braincase
(chondrichthyes)

2) Scaffold

Neurocranium

2

Agnathans Gnathostomes

SPLANCHNOCRANIUM Ostracoderms Bony fish

(=Visceral Skeleton)

1) support respiration
2) support feeding apparatus
3) later, jaws

SPLANCHNOCRANIUM
Î JAWS

General Functions

1) Prey Traps
2) Crushing

Romer Jarvik Jaw
Suspension
Articular
Amphistyly

Autostyly
Hyostyly

3

Figure 7.56

Synapsids

Quadrate Î Incus
Articular Î Malleus
(Hyomandibula) Î (stapes)

Cuvier

Sauropsids

Synapsids

Quadrate Î Incus
Articular Î Malleus
(Hyomandibula) Î (stapes)

4

(Diarthrognathus) Probainognathus

Quadrate

Articular
Lower jaw

(Diarthrognathus) Probainognathus

Dermatocranium

Derived from dermal Armour
Function

protect the brain

Amniotes

5

FUNCTION

1) Secondary

Water vs. Land FUNCTION

1) Secondary
2) Primary

respiration
feeding

prey traps
swallowing

FUNCTION

(feeding)

Aquatic

6

Agnathans

Suspension
feeders

(cilia-mucus)

Suction Feeders

(gape ‘n suck; inertial)
aquatic

Bass Hog sucker

7

FUNCTION Tongue

(feeding)

Air

8

Salamander Salamander
Salamander Lizard

Tongue Projectile Tongue

Gary Larsen Î

9

Prehension

Jaws

FUNCTION Swallowing

Swallowing Mastication

suspension
whole (gizzard)
mastication

10

Swallowing CRANIAL
KINESIS
Mastication
Relative motion of two or more
precise occlusion parts of the skull room.
specialized teeth
diphyodont (joint through skull roof)

(polyphyodont) CRANIAL
KINESIS
akinetic
Rapid change in size and
Cranial configuration of buccal
kinesis cavity.
Kinetic Tooth position

Akinetic

Kinetic Kinetic

11

Strike Kinematics

MODEL (minus mandible)

quadrate supratemproal braincase prefrontal

pterygoid ectopterygoid

maxilla

fang

mandible

Strike Kinematics

12

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