Dinosaurs

DINOSAURS

COMPILED BY HOWIE BAUM



THIS IS THE FIRST OF 3 PAGES THAT HELP TO PUT THE 165 MILLION YEAR REIGN OF
THE DINOSAURS, IN PERSPECTIVE.

IT IS A CALENDAR THAT IS DESIGNED SO THAT ALL OF THE TIME, SINCE THE BIG
BANG HAPPENED – 13.8 BILLION YEAR AGO, UP TO THE
PRESENT TIME, IS COMPRESSED INTO 1 YEAR.

period

First
Dinosaurs

Dinosaurs lived for 165 million years !!

Humans have only existed for 0.004% of
the age of the Earth !



The rocks of the Cincinnatian series
were deposited between
approximately 451 and 443 million
years ago, during the Ordovician
period, when all the land was
underwater !

BASIC DINOSAUR FACTS

•Dinosaurs are a group of reptiles that have lived

on Earth for about 165 million years.

About 60% of dinosaurs ate plants (herbivores)
and 40% ate meat (carnivores)

•In 1842, the English naturalist Sir Richard Owen coined
the term Dinosauria, derived from the Greek deinos,
meaning “fearfully great,” and sauros, meaning “lizard.”

•Dinosaur fossils have been found on all 7 continents.

•All non-avian (non-bird) dinosaurs went extinct
about 66 million years ago (MYA).

•There are roughly 700 known species of extinct
dinosaurs.

•Modern birds are a kind of dinosaur because they share
a common ancestor with non-avian dinosaurs.

The Archosaurs
consist of
a diverse group of
Triassic living and
extinct reptiles
that are
subdivided into
crocodiles, the
2 main types of
dinosaurs, and
pterosaurs.

ORNITHISCHIAN AND As shown above, the pubis bone in the
SAURISCHIAN DINOSAURS Saurischian dinosaurs points forward.

As shown on the previous diagram, there
are 2 types of Dinosaurs.

Dinosaurs and reptiles have hip girdles,
or pelvises, and all of them are composed
of three bones: the ilium, ischium, and
pubis.

All ornithischians are united by a
pubis pointing backward, running
parallel with the ischium.

The name "Ornithischia" means "bird-
hipped," and birds also have pelvises in
which the pubis points backwards.

However, birds are more closely
related to the Saurischia, or "lizard-
hipped" dinosaurs, than to the
ornithischian dinosaurs.

necks

DINOSAURS

Dinosaurs first appeared during the Triassic
period, between 243 and 233.23 million
years ago.

They became the dominant terrestrial
reptiles throughout the Jurassic and
Cretaceous periods.

The fossil record demonstrates that
birds are modern feathered dinosaurs
because they evolved from ones that
lived during the Late Jurassic period.

So birds were the only dinosaur
lineage to survive the Cretaceous–
Paleogene extinction event,
approximately 66 million years ago.

Dinosaurs lived Time of the Dinosaurs
during the Mesozoic
time period, for 165
million years.

This was during the
Triassic, Jurassic,
and Cretaceous time
periods.

The Mesozoic was
described as the
“Age of the Reptiles”

THE AGE OF REPTILES

The Mesozoic is an era that started at 252.2 million years ago to 65.5 million years ago,
and is composed of the Triassic Period, the Jurassic Period, and the Cretaceous
Period.

The Mesozoic was a place of giants, with dinosaurs ruling the world.

They first evolved from Archosaurs into dinosaurs during the Triassic Period, turned larger
and more diverse in the Jurassic and Cretaceous periods, but got wiped out by the
Cretaceous–Paleogene (K–Pg) extinction event, at the end of the Cretaceous period.



THE 2 MAIN PHYSICAL CHARACTERISTICS

OF DINOSAURS Archosaur ankles: The two major groups of

archosaurs are distinguished by differences in the

joint of their ankle.

The crocodiles and their relatives have an ankle
joint (at left), while dinosaurs and pterosaurs
(flying reptiles) have an ankle joint (at right).

The red line in each image shows the plane of the
ankle hinge.

THE CINCINNATIAN TIME PERIOD

The Cincinnati area was under an inland sea for millions
of years, during the Ordovician period (485 – 443 MYA)
and there was all kinds of underwater life at that time
but it was before there were any fish here.

The Cincinnatian layer is in the Ordovician period range
and was here 451 to 443 MYA. This is why it is such a
good fossil hunting area.



People who study the history of animals and fossils are called Paleontologists. As part of their
training, they are asked to remember all of the names of the different time periods .

A mnemonic is a shortcut way to remember things like this and one of those used for this set,
starting with the Cambrian period is:

“Cows Often Sit Down Carefully. Perhaps, Their Joints Creak? Please, No Questions”

This graph shows
the changes in the
Carbon Dioxide in
the air, during the
various time
periods.

Notice that it
peaked during the
Cambrian period
and was still
somewhat high
during the Triassic,
Jurassic, and
Cretaceous
periods, when the
Dinosaurs lived.

EARTH'S MAGNETOSPHERE ALLOWS
US TO HAVE AN ATMOSPHERE

Life on Earth initially developed and
continues to be sustained under the
protection of this magnetic environment.

The magnetosphere shields our home
planet from solar and cosmic particle
radiation, as well as erosion of
the atmosphere by the solar wind - the
constant flow of charged particles
streaming off the sun.

Early Earth had a low-oxygen
atmosphere created by volcanic
gases.

The Great Oxygenation Event
(GOE) responsible for rise in
Oxygen levels, which occurred
nearly 2.3 billion years ago, is
essential for all of the Life on
Earth today.

It was the result of the growth of
plants that took in Carbon Dioxide
and released Oxygen.

Algae and microbial mats of plant material
produce Oxygen and take in Carbon
Dioxide for their growth process.

STROMATOLITES UNDER THE
OCEAN

Stromatolites and microbial mats
are diverse and complex ecosystems
where different species of bacteria
and other microbes work
together to produce oxygen.

They have been around and
growing for 3 billion years ago.

They are only found to a depth of 4
meters because some of the microbes
forming them, cyanobacteria, require
sunlight.





252.2 – 199.6 MILLION YEARS AGO
(MYA)

THE TRIASSIC PERIOD

200 million years ago, dinosaurs roamed the
supercontinent Pangea which extended from pole
to pole, surrounded by the Pantha-lassic Ocean,
the oceanic ancestor of the Pacific Ocean.

❖ At the end of the Triassic era, 80% of species
died.

❖ Pangea supercontinent combines all major
landmasses

❖ Panthalassa combines all oceans except Tethys

❖ The climate was very hot and dry with huge
deserts at the center of the land mass.

❖ Archosaurs wildly diversify, becoming the
crocodilians, the flying Pterosaurs, and
Dinosaurs.

It is
interesting
to note that
before
Pangea
started to
break apart,
the lower
part of
North
America
was at the
Equator !!

Ancient fossils of the same Wegener used fossil evidence to support his
species of extinct plants and continental drift hypothesis. The fossils of these
animals are found in rocks of organisms are found on lands that are now far
the same age but are on apart.
continents that are now widely
separated .

Alfred Wegener proposed that
the organisms had lived side
by side, but that the lands had
moved apart after they were
dead and fossilized.

He suggested that the
organisms would not have
been able to travel across the
oceans.



THE MESOZOIC ERA

The Mesozoic era includes the 3 main time
periods when the Dinosaurs lived:

1) Triassic

2) Jurassic

3) Cretaceous.

As the Mesozoic era begins, we see the rise
of the dinosaurs, during the later part of the
Triassic Era which is 252-201 Million Years
Ago so it lasted for 51 million years.

Pterosaurs (flying reptiles) also made their first
appearance here as well as frogs, turtles, and
crocodiles.

During the Late Triassic period, many small
mammals also arose.

THE TRIASSIC PERIOD

As mentioned, the Triassic period -
spans almost 151 million years.

It began in the wake of the
Permian–Triassic extinction event,
which left the Earth's biosphere in
bad shape.

It was well into the middle of
the Triassic before life
recovered its former diversity.

A specialized subgroup of
archosaurs, called dinosaurs,
first appeared in the Late
Triassic but did not become
dominant until the succeeding
Jurassic Period.

PLEUROMEIA TREES

After the big Permian-Triassic
extinction when most plants
died out, these trees grew
everywhere around the world
during the Triassic period.

It was a smaller tree with a
single, unbranched trunk
topped by a tuft of grass-like
leaves, with one or 2 side
cones and a main one at the
top.

It reproduced from spores in
the cone at the top of the tree.

PLANTS THAT
LIVED DURING
THE TRIASSIC

PERIOD

The environment
was dominated
by conifers
(evergreen
trees), ferns and
a now-extinct
group of plants
known as the
seed ferns.

Most ferns did
and still
reproduce with
small packets of
spores on the
under side of
their leaves.

Nyasasaurus
parringtoni

This dinosaur is believed
to be the one of the first
ones that walked the
Earth about 243 million
years ago, during the
Triassic period.

There were probably
others similar to it that
lived before then, but
their fossils haven’t been
found yet.

The video of the dinosaur
Troodon is shown, which
is very close in size to
Nyasasauruas.

COELOPHYSIS

One of the first true dinosaurs in
the Triassic period was Coelophysis
("hollow form"), a carnivorous,
bipedal predator that emerged in
the late Triassic, between 225
and 220 Million years ago
(MYA).

With Hollow bones, it grew up to
10 feet in length, weighed around
60 pounds and probably fed on
smaller reptiles and amphibians.

It had curved claws on its hands
and a slim head crammed full of
very sharp teeth.

HERRERASAURUS

Found in the late Triassic
period in northwestern
Argentina, Herrerasaurus
is an early archosaur
which is the main
classification for
dinosaurs.

The first specimen was
found in 1958 by
Victorino Herrera, for
whom the fossil was
named.

It was a large carnivore
about 20 feet long and
they weighed up to 770
pounds.

OTHER CHINDESAURUS
TRIASSIC
DINOSAURS

As mentioned,
dinosaurs
didn’t start to
appear until
the end of the
Triassic period.

These are
some others
that lived at
that time.

STAURIKOSAURUS

EORAPTOR COLORADISAURUS
LILLIENSTERNUS LYCORNIS

MELANOROSAURUS

MUSSAURUS



The Jurassic period began the Age of the
Ruling Reptiles, 208-144 Million Years Ago.

During this period, vegetation was greener
and more abundant.

By the Late Jurassic, huge dinosaurs such
as Stegosaurus, Ceratosaurus,
Brachiosaurus, and Allosaurus walked the
lands.

Flying reptiles ruled the skies.

The earliest known birds also appeared.

WILLIAMSONIA PLANTS

Williamsonia was a significant
plant during the Jurrasic time
period.

It possessed a sturdy stem and
had multiple fern-like leaves.
The plant did not live in groups.

They produced flowers up to 4
inches in length.

Its stalked seeds would have
grown from a central
receptacle, and the entire
flowers would each have been
surrounded by protective
coverings.

By the beginning of the
Jurassic, the
supercontinent Pangaea
had begun dividing into 2
landmasses: Laurasia to
the north, and Gondwana
to the south.

This created more
coastlines and shifted the
continental climate from
dry to humid, and many of
the arid deserts of the
Triassic were replaced by
lush rainforests.

COMPSOGINATHUS

It was one of the smallest
carnivore (meat-eating)
dinosaurs. It caught and
ate small animals,
including insects and
lizards.

It was 4.6 feet long, 10
inches tall, and weighed
6.5 pounds

It lived during the Jurassic
period, about 155 to 145
years ago.

DILOPHOSAURUS

It lived in Arizona during the
Early Jurassic, about 193
million years ago.

It’s name means "two-crested
lizard as it had a frill collar it
could expand to scare a
potential enemy. It also had
small feathers around its
body.

It was 23 feet long and
weighed about 880 pounds.
The one in the video is a
smaller size.

It was one of the earliest large
predatory dinosaurs and the
largest known land-animal in
North America at the time.

DRYOSAURUS

Dryosaurus
which means
tree lizard, lived
in forests in the
Western United
States in the
late Jurassic
period.

They were 8 to
14 feet long and
weighed up to
170 to 200
pounds.

HUAYANGOSAURUS

It lived around 165 million
years ago, some 20 million
years before its famous
relative, Stegosaurus
appeared in North America.

It grew up to 15 feet long
and weighed 1,000 pounds.

On its neck, back, and tail
were two rows of paired
small vertical plates and
spikes. On the rear of the
tail, pairs of spikes were
present forming the so-
called "thagomizer", a
defensive weapon which
was on all of the dinosaurs
in the Stegosaur family.

GIGANTSPINOSAURUS

Gigantspinosaurus meaning
"giant-spined lizard" is a
herbivorous dinosaur from
the Late Jurassic period.

It is another member of the
Stegosaur family that was
found in China.

KENTROSAURUS

They lived in the
Late Jurassic
period, in
Tanzania, about
152 million years
ago.

They grew to
15 feet long and
weighed about 1.1
tons.

CHUNGKINGOSAURUS

Chungkingosaurus,
meaning "Chongqing
Lizard", is a herbivorous
dinosaur from the Late
Jurassic period, in
China.

It is a member of the
Stegosaurus family of
dinosaurs.

STEGOSAURUS

They lived in the late
Jurassic period,
between 155 and 150
million years ago, in
the western United
States and Portugal.

They grew up to 29.5
feet long and weighed
up to 7.7 tons.

It and the 4 dinosaurs
shown previously are
all in the Stegosauridie
family, shown on the
next slide.