Prehistoric Creatures of the Past

Prehistoric
creatures
By VISHAL KANHAIYA 1
By VISHAL KANHAIYA 12/7/2012

Life
Life on Earth started around 3.8
billion years ago and has since
evolved and diversified through
the process of natural selection
to be adapted to almost every
environment possible. There
are currently an estimated 1.9
million animals, plants, and
other forms of life on Earth.
Life can be found in every nook
and cranny/niche of the globe,
from the extreme
environments of deep sea
hydrothermal vents and the
freezing conditions of the polar
regions to the lush habitats
found at the equator.
Looking back through time, by
means of the fossil and
phylogenetic record, we can
see that the Earth has been
home to many more species
than are alive today. Taking a
historical perspective shows
that life is constantly evolving,
with the success and
dominance of different groups
waxing and waning over time. By VISHAL KANHAIYA 12/7/2012 2

History of life on Earth
The history of life on Earth began about 3.8 billion years ago, during the Archean era, initially with
single-celled prokaryotic cells, such as bacteria. Multicellular life evolved over a billion years later and
it's only in the last 570 million years that the kind of life forms we are familiar with began to evolve,
starting with arthropods, followed by fish 530 million years ago (Ma), land plants 475Ma and forests
385Ma. Mammals didn't evolve until 200Ma and our own species, Homo sapiens, only 200,000 years
ago. So humans have been around for a mere 0.004% of the Earth's history.

Tree of life
With the publication of 'On the Origin of Species by means
of Natural Selection' on the 24th November 1859, Charles The centre represents the last universal ancestor of
Darwin not only explained how and why we have the all life on earth, the outer branches the major
diversity of life we see all around us, but also showed how biological groups.
all life is connected. The tree is based on research carried out by: David
Since then we have continued to gather evidence from a Hillis, Derrick Zwickl and Robin Gutell from the
range of different disciplines including physiology, University of Texas. It is based on analysis of small
biochemistry and DNA analysis. The evidence indicates thatsub-unit RNA sequences sampled from about 3,000
all organisms on Earth are genetically related, a species from throughout the Tree of Life.
genealogical relationship that can be represented as an
evolutionary tree known as the Tree of Life.
The Tree of Life illustrates how different species arise from
previous species via descent with modification, and that all
of life is connected. The diagram above shows the
relationship between the major biological groups. By VISHAL KANHAIYA 12/7/2012 3

Archelon
(ARK-eh-lon)

This giant turtle could live to
100 years old, possibly thanks
to taking long sleeps on the
seabed

Type: Reptile
Size: 4.6m
Diet: Omnivorous
Predators: Mosasaurs and sharks
Lived: Late Cretaceous, 75-65
million years ago
Archelon was a slow mover and found most of its food drifting near the sea surface. It had little
need to dive deep except when hibernating on the seabed. It was an omnivorous grazer,
sweeping up drifting fish, jellyfish and dead carrion as well as plants. Its sharp, powerful beak
could break open shelled animals such as ammonites.
It's huge flippers suggest it was a long distance swimmer happiest in the open ocean. It would
never be alone, as its huge size attracted a squadron of hangers-on such as juvenile fish as well
as barnacles and parasites. It couldn't withdraw its head or flippers inside its bony shell for
protection so, despite its size, it was an easy target for large predators.
Like modern turtles, it laid eggs by burying them in sandy beaches under cover of darkness. Its
4
nearest living relative is the world's largest turtle, the By VISHAL KANHAIYA 12/7/2012
leatherback.

Arsinoitheriu
m
(aars-in-oh-ith-EAR-ee-um)

Non-stop eating for this gentle
giant of Eocene mangrove
swamps.
Type: Mammal
Size: 1.8m high at the shoulder
Diet: Herbivore
Predators: Creodonts
Lived: Late Eocene and early
Oligocene, from 36 to 30 million
years ago.

It's most distinctive feature was the two large horns on their snouts. The horns were hollow and
possibly used to produce loud mating calls as well as to compete with rival males. It was a hefty
creature with thick, hairless skin resembling elephant hide.
It was very selective in the types of fruit and leaves it ate. Its size meant it had to eat a lot of
food - it probably spent much of its day chewing on something.
It lived in small groups and would have been in the water most of the time. It couldn't
straighten its legs, suggesting they were better for wading and swimming than for walking. Its
large size kept it safe from most predators, although creodonts might tackle a young
By VISHAL KANHAIYA 12/7/2012 5
Arsinoitherium.

Coelursaur
(See-LUR-oh-sawr)
Coelurosaurs are some of the most
primitive of all the dinosaurs. It is
from them that we get
Tyrannosaurus and other giant meat-
eaters.
Type: Primitive theropod
Size: 2-3m long
Diet: Carnivore
Predators: Large land reptiles like Postoschus
Lived: Mid Triassic to Early Jurassic, 230-200 million
years ago.

Around 230 million years ago the first dinosaur fossils started to be found in places such as South America,
Madagascar and Europe. These dinosaurs were much smaller than their later descendents and can be divided into
two groups: The prosauropod dinosaurs, which are the primitive vegetarian forerunners of sauropods such as
Diplodocus, and the more common coelurosaurs which were two-legged meat-eaters that would later evolve into
giants such as Tyrannosaurus and Allosaurus.The Triassic coelurosaur dinosaurs were small, nimble and built to
survive in the harsh Triassic landscape. Unlike many of the four-legged lumbering reptiles around them, the
coelurosaurs could use their two legs to travel at speed and to manoeuvre themselves out of dangerous situations.
Their light skulls, long snout and flexible necks were ideal for hunting small animals such as insects, amphibians
and other reptiles but the They could also live by scavenging when times were hard.The arrival of these dinosaurs
was a landmark in evolution. They quickly evolved into newer and larger species and spread themselves around
the globe until, by the start of the Jurassic period, the dinosaurs dominated the land. These helped found a
dynasty that produced the largest and most feared land predators of all time. After the giant extinction event of 65
million years ago the only Earthly legacy of the dinosaurs are the birds which split from the coelurosaur dinosaurs
sometime during the Late Jurassic period. By VISHAL KANHAIYA 12/7/2012 6

Basilosaurus

Scientific name:
Basilosaurus
Rank: Genus
Common names:king lizard
A pair of the early whales known as Basilosaurus

Basilosaurus ("King Lizard") is a genus of cetacean that lived from 40 to 34 million years ago in the Late Eocene. Its
fossilized remains were first discovered in the southern United States (Louisiana), and were initially believed to be
some sort of reptile, hence the suffix -"saurus", but later found to be a marine mammal. Richard Owen wished to
rename the creature Zeuglodon ("Yoked Tooth"), but, per taxonomic rules, the creature's first name remained
permanent. Fossils from at least two other species of this taxon have been found in Egypt and Pakistan.
Basilosaurus averaged about 18 meters (60 ft) in length, and is believed to have been the largest animal to have
lived in its time. It displayed an unparalleled degree of elongation compared with modern whales. Their very small
vestigial hind limbs have also been a matter of interest for paleontologists. The species is the state fossil of
Mississippi and Alabama in the United States. They lived in the Eocene epoch.
Basilosaurus fossils were first discovered in Louisiana, USA in the 1830s. Believed to be giant reptilian sea
monsters, they were named Basilosaurus, or 'king lizards'. Later, they were shown not to be reptilian but gigantic,
ancient whales. They were more elongated than modern whales and had a pair of small legs, that could have been
a hangover from their terrestrial ancestry. A large number of fossils of these marine predators has been found to
date, leading to the conclusion that Basilosaurus were common By VISHAL KANHAIYA 12/7/2012of the time.
in the warm shallow seas 7

Cymbospondylus
(sim-bow-spon-DEE-lus) Type: Marine reptile
Size: 10m long
Diet: Carnivore
Predators: Few, if any, predators once fully grown
Lived: Late Triassic, 240-210 million years ago.
A powerful dolphin-like
swimmer whose sharp
teeth ruled the Triassic
seas.
It was an early member of the Icthyosaur group, which looked slightly like modern dolphins.
It had no dorsal fin and its tail was long like an eel's.
Its long tail made it a powerful swimmer, it patrolled in deep offshore waters looking for prey.
It had a skull 1m long with short, sharp teeth good for grabbing quite large reptiles but it favored fish
and cephalopods such as ammonites. These appears to have given birth to live young as it had no way
to
lay eggs.


Dunkleosteus
(dunk-lee-OWE-stee-us)
Speedy, powerful and happy to
eat most things - this was the
creature to avoid, 360 million
Type: Placoderm fish
years ago.
Size: 8 to 10m
Diet: Carnivore
Predators: Probably none
Lived: Late Devonian, 370-360 million years
ago.
It looked like the violent brute it was: powerfully built and armour-plated round its head. It was streamlined and
shark-like. It lacked true teeth, instead it had two long bony blades that could snap and crush almost anything.
Pigment cells suggest Dunkleosteus had dark colors on its back and was silvery on its belly.
This fish was anything but picky with its food. It ate fish, sharks and even its own kind. And it seems that It suffered
from indigestion as a result: its fossils are often associated with regurgitated, semi-digested remains of fish. It may
have been one of the earliest animals to exist as male or female, meaning that pairs of fish had to mate physically.


Elasmosaurus
(eh-LAZZ-mo-SAW-rus)

A dinosaur of the seas which swam thousands
of miles and could surprise its prey thanks to an
incredibly long neck.
Type: Plesiosaur
Size: 15m long
Diet: Carnivore
Lived: Late Cretaceous, 85-65 million years ago.

A bizarre creature whose body was dwarfed by its long, thin neck and tail, Elasmosaurus swam using four
flippers.It was a carnivorous hunter which used its long neck to get close to prey without them noticing. A
swift flick of the neck could catch them unawares. Its small head limited the size of what it could eat.
Elasmosaurus spent all its time in the water, often cruising coastal waters for shoals of fish. It would
occasionally dive down to the seabed in shallow areas to find rounded pebbles. In its stomach, these aided
digestion and provided ballast.Elasmosaurus travelled long distances to find mating and breeding grounds.
There is evidence it may have given birth to live young which it reared until they were old enough to look
after themselves.


Giant Mosasaur
(JY-ant MOES-ah-SAWR)
A group of supreme killers that had few
enemies, except for each other.
Type: Marine reptile
Size: Up to 17m in length
Weight: maximum 20 tonnes
Diet: Carnivore
The mosasaurs were one of the success stories of the late Cretaceous period. The largest known mosasaur
is Hainosaurus, which could reach 17 metres in length. Giant mosasaurs were the top predator in the sea
and were widespread across the world.Much of their day would have been spent swimming slowly near the
seabed looking for suitable prey to attack. Their diet consisted of slow moving animals like ammonites,
birds and turtles but they would also tackle larger and swifter prey, such as sharks and plesiosaurs, when
the opportunity arose. As the mosasaurs were not fast swimmers they would have stalked their prey using
natural cover provided by seaweed and rocks. Only when the prey was within striking range would the
mosasaur propel itself forward. Being caught in a mosasaur’s jaws meant almost certain death.
Although giant mosasaurs were the top predators in the sea, they were still vulnerable to attack. One
mosasaur fossil bears the marks of a shark bite in its spine.


Giant orthocone
(OR-thoe-cone)

Type: Cephalopod mollusc
Size: Up to 11m long
Diet: Carnivore
Predators: Giant orthocone was the top predator of
its time
Lived: Late Ordovician and early Silurian, 470-440
million years ago.
460 million years ago, the biggest animal on Earth
was a jet-propelled cone with tentacles.

The giant orthocone's living tissue was at one end of a very long conical shell. It had no fins and no tail.
Along the underside of the cone ran a flexible, fleshy tube. The orthocone moved along by forcing water
out in the opposite direction to where it wanted to go. It controlled its vertical position by adjusting the
amount of seawater in the chambers of its shell. Its mouth and metre-long tentacles emerged from one
end of the shell.It ate fish as well as arthropods, eg sea scorpions. It seized its prey using its tentacles and
beak-like mouth to rip apart.


Halisaurus
(HAL-i-SAWR-uss)

Size: 3-4 metres in length
Diet: Carnivore
Predators: Other mosasaurs
Lived: Late Cretaceous, 85-65 million
The first mosasaur fossils were discovered around
years ago. 1780, almost 50 years before the first dinosaur fossil.

Halisaurus was a mosasaur. But it was much smaller than its giant relatives like Hainosaurus. It
loitered in submarine caves and and cracks. It may have waited around ledges above the water
where hesperornis gathered.When the hesperornis leave their rocky ledges to dive for fish, the
halisaurus are down below, waiting for an opportunity to ambush them.
Mosasaur teeth are good at piercing the skin of their prey but bad at slicing flesh. So once
halisaurus has caught its prey, it swallows it. Its jaw has flexible joints within it and can open
incredibly wide.Like other mosasaurs, Halisaurus has extra teeth called pterygoid teeth, that it
uses to hold on to its prey while its jaw moves forward to swallow the hapless victim whole.


This giant
Hesperornis bird made
(HES-per-OR-nis) more use
Type: Flightless bird of its teeth
Size: 2m high than its
Diet: Carnivore wings.
Predators: Sharks, plesiosaurs, dinosaurs
It had a sleek, feathered body and long legs with webbed feet. Its wings were small, used for steering
when diving underwater. Its long jaws had many small sharp teeth. It was a marine predator, eating
fish, ammonites and belemnites.
It lived in warm seas, coming ashore only to breed. Ungainly and vulnerable on land - Hesperornis
couldn't walk - they crowded together in colonies for safety and chose inaccessible rocky outcrops.
It spent most of its time floating on the sea surface. It travelled long distances by a combination of
swimming and drifting. It was a speedy swimmer, taking short dives to feed on shoals of fish or other
passing food. Its legs could not support its weight so on land it had to push itself along on its belly.
Unable to fly or walk, It needed to be wary of predators: sharks and plesiosaurs at sea, dinosaurs and
pterosaurs on land.


It had over
Leedsichthys 40,000 teeth
(Leeds-ICK-thees) which were used
Type: Ray-finned fish to sieve small
Size: Up to 27m animals from the
Diet: Filter feeder water. It is
probably the
Predators: Liopleurodon,
largest fish ever
Metriorhynchus, Hybodus sharks to have lived.
Lived: Late Jurassic, 165-155 million years
It was
ago a giant fish that would have dwarfed every other animal in the sea, but it was a gentle giant that lived on the
tiny shrimps, jellyfish and small fish that make up plankton. It would have swum slowly through the upper waters
of the ocean, taking mouthfuls of plankton-rich water and sieving them through the giant mesh-plates at the back
of its mouth. Its feeding habits were similar to the modern blue whale, which also survives on nothing but
plankton.
They probably travelled large distances to find parts of the world where seasonal conditions caused plankton to
form itself into a dense concentrated organic soup. Once a year, and probably after plankton feasts, Leedsichthys
would have shed the giant filter plates from the back of its mouth, meaning it was unable to feed itself for several
weeks, whilst the new ones grew back. Towards the end of this time it would have become weakened through
hunger and vulnerable to attack.
The Jurassic seas in which these lived were a dangerous place and despite its size, it had no formal means of
defending itself against predators such as Liopleurodon and Metriorhynchus. One attack would be unlikely to kill a
full-grown Leedsichthys, but several predators could have inflicted fatal damage, leaving this defenseless giant to
die slowly from its wounds.


This giant
Liopleurodon predator
(LI-PLOO-ro-don) would
dwarf a
Type: Marine reptile living sperm
Size: 25m long whale
Diet: Omnivore
Lived: Mid to Late Jurassic, 160-155 million years
It was the mightiest aquatic predator of all time. Its 25 meter long
body would have cruised silently through the shallow seas of the late
Jurassic, propelled by its flapping flippers.
It was a hunter. Its long jaws and rows of needle-sharp teeth would
have made marine crocodiles, the giant fish Leedsichthys,
ichthyosaurs and even other pliosaurs vulnerable to attack. Its nose allowed it to smell underwater. This
allowed it to smell its prey from some distance
away. Despite needing to breath air, It spent its
entire life at sea and was unable to leave the
water. Consequently, it would have given birth
to its young alive and may have visited
shallower water to breed.
Until recently the longest confirmed adult
specimen was 18 meters. But in 2003 a fossil
pliosaur (possibly a Liopleurodon) was
discovered in Mexico which was 18 meters long
and still a juvenile - suggesting that they grew
considerably larger than this.

Twice the size
Megalodon of a great white
(MEG-a-la-don) shark, and with
teeth 21cm
Type: Cartilaginous fish long, this was
Size: Up to 16m in length the top
Diet: Carnivore predator of its
Predators: No known predators time.
Lived: The Miocene and Pliocene epochs, 16-1.6 million
years ago.

Streamlined and muscular, It had jaws over 2m wide. While it could eat whatever it chose, its favourite food
was whale. Other kinds of marine mammals such as seals and Odobenocetops were also on its menu.
Most of this shark's hunting was in the open sea (juveniles lived closer to shore). It attacked its prey near
the surface, when it came up for air.It could swim at high speed in short bursts so tended to rush its prey
from beneath. Especially when tackling large species, it would first aim to disable its prey by injuring a
flipper or the tail. Once unable to swim properly, the victim would be easy to finish off.


This
Metriorhynchus snappy
(MET-ri-oh-RINK-us) hunter
Type: Marine Crocodile could grab
pterosaurs
Size: 3m long
in mid-
Diet: Carnivore
flight.
Predators: Liopleurodon
Lived: Mid Jurassic, 160-150 million years
At 3
ago.meters long it was shorter than many living crocodiles but it would have been far more deadly. Its body
was streamlined and its tail was long and powerful, and would have propelled it gracefully through the
water by using a strong sideways sweeping motion.
It was a versatile hunter, eating everything from the slow moving ammonites and belemnites to faster prey
such as the giant fish Leedsichthys and even pterosaurs. It probably did this by resting with its head just
under the surface so that only its nostrils remained above the surface. Then when a pterosaur strayed too
close, it would give a powerful stroke with its tail and lunge out of the water, clasping the unfortunate flying
reptile in its jaws. Despite its powerful hunting ability, it was relatively defenseless against other larger
hunting reptiles like the liopleurodon. Unlike modern crocodiles, It lost most of its armor in order to be able
to swim faster. It was so adapted to life at sea that it probably only returned to land to mate and to lay its
eggs. It was not very graceful when out of the water and would have returned to the sea immediately after
laying its eggs. The young would have hatched on their own, making a hazardous journey down the beach
to the sea.


Nothosaur
(NOTH-oh-sawr)

Size: Up to 4m long A predatory reptile ahead of its time, happiest in
Diet: Carnivore the water but also able to haul out onto dry land.
Predators: Dinosaurs
Lived: Triassic, 240-210 million years ago.
A little bit like a crocodile, Nothosaurs had a long flat tail and short
stumpy legs. Plus it had a mouth full of needle-sharp teeth. Speed and
agility helped it ambush fish as well as cephalopods and small reptiles.
Although the water was its natural habitat, it came ashore to
sunbathe. And like turtles nowadays, female Nothosaurs hauled
themselves well above the high water mark to bury their clutch of
eggs.


This strange
Odobenocetops creature had
(oh-doh-ben-OH-set-ops) lopsided tusks,
Type: Marine mammal no teeth and
sucked its food
Size: 2.1m long
out of hiding
Diet: Carnivore
places.
Predators: Megalodon sharks
Lived: Pliocene, 3-5 million years ago.
Its two 25cm tusks made It look like a cross between a walrus and a manatee. In males only, the right hand
tusk grew much larger - up to 1.35m long. It didn't have any teeth.
It cruised in shallow water staying close to the seabed where it was safest. One species had an echolocation
organ, similar to that of modern dolphins.
By grubbing around in the mud, It found worms and shellfish to eat. Muscular lips allowed it to suck clams
out of their shells. It was an air-breathing mammal so had to rise to the surface in between dives. It used its
powerful tail to swim around. It had good eyesight but despite its size, it had little defense against sharks.
The tusks were not strong enough to be much use in a fight.


A bizarre fin
Stethacanthus marked this
(STETH-ac-anth-us) early shark out
from the crowd
Type: Cartiliginous fish
in the Devonian
Size: 0.7-2m long
oceans.
Diet: Carnivore
Predators: Dunkleosteus
Lived: Lived 370-345 million years ago, in the late
Devonian and through the Carboniferous era.
It resembled modern sharks to an extent, except for its outrageous dorsal fin - the shape of an ironing
board - that it seems was part of courtship display as it is found in the males only. The top of this fin was
covered in rough, tooth-shaped scales that match a patch of skin on the snout of it. Was this supposed to
mimic a huge mouth and make the creature appear more frightening? It tended to patrol shallow coastal
waters on the lookout for food. It ate small fish, crustaceans and cephalopods (e.g. goniatites).There's
evidence that It may have been migratory, returning to particular places to mate and give birth. It could
certainly swim quite fast, although not quickly enough to evade a hungry Dunkleosteus.


Tanystropheus
(TAN-ee-STRO-fee-us)

Tanystropheus had a snap-off tail and the longest
Type: Reptile neck possible within the laws of physics.
Size: 6m long
Diet: Carnivore
Lived: Late Triassic, 235-210 million years ago.

Three quarters of Its body length was its neck and tail. If its neck had been any longer its head
might have snapped off. It lived in shallow waters but came ashore too. On land, It ate insects
and small reptiles. In the water, it would gobble up fish and ammonites. It was not a fast
swimmer so often walked along the seabed and used its long neck to get within range of prey
without being noticed. Like some lizards alive today, its tail could detach if seized by a
predator, to allow an escape. It would then regrow.


With a top speed
Xiphactinus around 60km/h, this
(zie-FAK-tin-us) immense fish was
Type: Bony fish always likely to be
Size: Up to 6m long "the one that got
Predators: Sharks such as Cretoxyrhina away".
It had a dark blue back and light silver belly to camouflage it from above and below. Sharp teeth at
one end and a powerful tail at the other combined to make it a formidable pursuit hunter. It cruised
in surface waters of the oceans. It caught other large fish (swallowing creatures up to 2m long whole)
and was prepared to have a go at seabirds on the surface, like a floating Hesperornis. Above all else,
It was a great swimmer, able to speed towards or away from virtually anything else in the seas of the
time. It may have been able to leap above the waves at times to help dislodge parasites from its skin.
It was not however immune from attack. If injured, its large size meant it was easy to spot and could
become prey for sharks.


Scientific name: Eurypterida
Sea Rank: Order
Common names: broad
scorpions
Sea scorpions, or
eurypterids, were
wing
the largest
arthropods the
world has ever seen
and could grow to
2.5 metres long.
They had a pair of
pincers, and in
some species these
too could become
very large. Sea A eurypterid -
scorpions were also known as a
predators that were sea scorpion -
in their heyday in catching the
the Silurian and heavily armoured
Devonian, though fish, Pteraspis
they survived into
the Permian. The
name sea scorpion
is something of a Trace fossils
misnomer, as they Habitats
Sea beds It's not only the actual bodily
also inhabited
Shallow seas remains of dead animals and
freshwater and may
Rivers and Streams plants that can become fossils.
have ventured on to
Estuaries Things created or left behind
land now and then.
Wetlands by animals can also fossilise,
They are related to
Lakes and Ponds such as their footprints,
scorpions,
Intertidal zones burrows and dung.
horseshoe crabs By VISHAL KANHAIYA 12/7/2012 24

What killed them
Sea When they lived
Eurypterids (sea scorpions) are an extinct group of
scorpionsto arachnids which include the largest
arthropods related
Ordovician period
Silurian period
known arthropods that ever lived. They are members of Devonian period
the extinct order Eurypterida (Chelicerata); which is the Carboniferous period
most diverse Paleozoic chelicerate order in terms of Permian period
species. The name Eurypterida comes from the Greek
word eury- meaning "broad" or "wide" and the Greek word
The Permian mass extinction
pteron meaning "wing", for the pair of wide swimming
has been nicknamed The
appendages on the first fossil eurypterids discovered.
Great Dying, since a
Eurypterids predate the earliest fishes. The largest, such as
staggering 96% of species
Jaekelopterus, reached 2.5 metres (8 ft 2 in) or more in
died out. All life on Earth
length, but most species were less than 20 centimetres
today is descended from the
(8 in). They were formidable predators that thrived in
4% of species that survived.
warm shallow water, in both seas and lakes, in the
Ordovician to Permian from 460 to 248 million years ago.
Although informally called 'sea scorpions', only the earliest
ones were marine (later ones lived in brackish or
freshwater), and they were not true scorpions. According Behaviours
to theory, the move from the sea to fresh water probably Adapted to running
occurred by the Pennsylvanian subperiod. They went Adapted to swimming
extinct during the Permian–Triassic extinction event 251 Moulting
million years ago, and their fossils have a near global Predators
distribution.About two dozen families of eurypterids are Egg layer
known. Perhaps the best-known genus of eurypterid is
Eurypterus, of which around 16 fossil species are known.
The genus Eurypterus was created in 1825 by James
Ellsworth De Kay, a zoologist. He recognized the
arthropod nature of the first ever described eurypterid
specimen, found by Dr. S. L. Mitchill. In 1984, that species, By VISHAL KANHAIYA 12/7/2012 25
Eurypterus remipes was named the state fossil of New

Geological time
Origin of the Earth 4.6 billion years ago

Archean era
Cryogenian period
Ediacaran period
Cambrian period
Ordovician period
Silurian period
Devonian period
Carboniferous period
Permian period
Triassic period
Jurassic period
Cretaceous period
Palaeocene epoch
Eocene epoch
Oligocene epoch
Miocene epoch
Pliocene epoch
Pleistocene epoch
Holocene epoch


Began: 3.8 billion years
Archean era ago
It was during the Archean Ended: 2.5 billion years
era that life first arose on
Earth. At this time there
were no continents, just
small islands in a shallow
ocean. There was a vast
amount of carbon
dioxide in the
atmosphere, but since
the sun was much fainter
back then, the combined
effect did not raise
Earth's temperature to
an extreme. Such levels
of carbon dioxide would
be toxic to the majority
of animals alive today -
as would the low oxygen
levels.

The Archean is a geologic eon before the Paleoproterozoic Era of the Proterozoic Eon, before
2.5 Ga (billion years, or 2,500 Ma) ago. Instead of being based on stratigraphy, this date is
defined chronometrically. The lower boundary (starting point) has not been officially
recognized by the International Commission on Stratigraphy, but it is usually set to 3.8 Ga, at
the end of the Hadean Eon. In older literature, the Hadean is included as part of the Archean.
The name comes from the ancient Greek ,meaning "beginning, origin".

Began: 850 million years ago
Cryogenian period Ended: 635 million years ago
A succession of incredibly harsh ice ages
waxed and waned during the
Cryogenian. It is nicknamed Snowball
Earth as it's been suggested that the
glaciation was so severe it may even
have reached the equator. Life during
the Cryogenian consisted of tiny
organisms - the microscopic ancestors
of fungi, plants, animals and kelps all
evolved during this time.

The Cryogenian is a geologic period that lasted from 850 to 635 million years ago. It forms the What the Earth was like
second geologic period of the Neoproterozoic Era, preceded by the Tonian Period and
followed by the Ediacaran. The Sturtian and Marinoan glaciations, which are the greatest ice
ages known to have occurred on Earth and may have covered the entire planet, occurred Snowball
during this period. These so-called 'snowball earth' events are the subject of much scientific Earth
controversy. The main debate involves whether these glaciations were truly global or merely
localised events. The period has not received the international ratification that all geological
time periods undergo (the most recent being the Ediacaran Period, which was ratified in
Ice age
2004). The start of the period is defined only on the ages of the rocks and not on any
observable and documented global event. This is problematic as estimates of rock ages are
variable and are subject to laboratory error. For instance, the Cambrian Period is marked not
by rock younger than a given age (542 million years), but by the appearance of the worldwide
Treptichnus pedum diagnostic trace fossil assemblage. This means that rocks can be
recognised as Cambrian when examined in the field and do not require extensive testing to be

Ice age
The last ice age hasn't ended, the
climate has just warmed up a bit
causing the ice sheets to retreat. When
the ice was more extensive, our
climate was very different. Firstly, lots
of the world's water was turned to ice,
so precipitation was low: Europe
received roughly half the rainfall it gets
today, mostly in the summer months.
Globally, summer temperatures were
4-8 Celsius colder than today. In some
places, the winter temperatures were
15-20 Celsius cooler than today's,
making ice age Florida more like
modern Quebec. Wind speeds were
higher and dust storms were common
as the wind picked up material from
enlarged deserts and glacier margins.
The ice age was at its most extreme -
and the climate at its most severe -
18,000 years ago.

period when this happened

Cryogenian Carboniferous Permian Pleistocene
period period period epoch

12/7/2012 29
By VISHAL KANHAIYA

Began: Permian mass extinction248 million years ago
Triassic period Ended: Triassic-Jurassic mass extinction205 million years
The Triassic began after the worst ago
mass extinction ever, at the end of the
Permian. Life on Earth took a while to
recover and diversify. The Triassic was
characterised by heat, vast deserts and
warm seas. Even the polar regions
were warm, so lush forests grew there.
However, the lack of other life, coupled
with the period's particular
environmental conditions, opened up
some evolutionary opportunities. As a
result, the very first mammals and
dinosaurs evolved. During this time,
the giant supercontinent of Pangaea
began to break apart. The period
ended as it had begun, with an
extinction event that wiped out many
species.

Desert Earth What the Earth was like
A vast desert formed in Earth's
prehistoric past when the
supercontinent of Pangaea
straddled the equator and
stretched to the poles.
Pangaea's position influenced
ocean circulation patterns, and
its huge size meant that there
were vast areas where moist air
from the oceans never By VISHAL KANHAIYA 12/7/2012 30

Began: Triassic-Jurassic mass
Jurassic period extinction 205 million yrs.
The Jurassic began after ago
the mass extinction Ended: 142 million yrs. ago
event that ended the
Triassic. Life, however,
was quick to recover
from this blow and the
Jurassic eventually
became host to the most
diverse range of
organisms that Earth had
yet seen. Amongst them
were the first birds and
some of the dinosaurs.
Continental break-up
during this time gave rise
to the sea that would
eventually widen to
become the Atlantic
Ocean. The ocean floor
that formed at this time What the Earth was like
is the oldest surviving on What grew then
the planet - all older ones
having now been
'recycled' through plate
tectonics.
Types of fossils formed in this period


DINOSAU Scientific name: Dinosauria
RS Rank: Superorder
Common names:
terrible, powerful, wondrous
lizard

Dinosaurs were the dominant land animals for 160 million years, making them one of the most successful groups of
animals ever. The name dinosaur translates as 'terrible or wondrous lizards' and they certainly evolved in a diverse range of
sizes and shapes, from the gigantic plant-eating sauropods to the quick meat-eating tyrannosaurs. They also sported an
impressive array of body modifications including horns, scales and crests. So far, the remains of over 1,000 different
dinosaur species have been identified from fossils though technically, birds are feathered12/7/2012
By VISHAL KANHAIYA
dinosaurs, meaning dinosaurs 32
aren't really extinct at all.

When they lived

Triassic period

Jurassic period

Cretaceous
period


Scientific name: Allosaurus
Allosaurus Rank: Genus
They were big, mean killing machines that
reigned supreme during the late Jurassic period.
They were the most common huge predators in
North America 140 million years ago, reaching an
impressive 12 meters in length and weighing up to
four tonnes. These carnivorous dinosaurs could rip
and tear chunks out of the large plant-eating
sauropods and stegosaurs of the time. The
enormous jaw was filled with long, serrated, back-
curving teeth. Near perfect examples of this
classic shaped theropod dinosaur were discovered
in Wyoming and called Big Al and Big Al Two. Its
fossil remains are extremely rare outside America.
They lived in the JURRASIC PERIOD.

Allosaurus in a
dry and sandy
landscape
Allosaurus size


Allosaurus Behaviours
It is a genus of large theropod dinosaur that lived 155 to 150 million years ago
Carnivorous
during the late Jurassic perio). The name Allosaurus means "different lizard".
It is derived from the Greek allos ("different, other") and sauros ("lizard").
The first remains that can definitely be ascribed to this genus were described
in 1877 by paleontologist Othniel Charles Marsh. As one of the first well-
known theropod dinosaurs, it has long attracted attention outside of
paleontological circles. Indeed, it has been a top feature in several films and Egg layer
documentaries about prehistoric life. It was a large bipedal predator. Its skull
was large and equipped with dozens of large, sharp teeth. It averaged 8.5
meters (28 ft) in length, though fragmentary remains suggest it could have
reached over 12 meters (39 ft). Relative to the large and powerful hind limbs,
its three-fingered forelimbs were small, and the body was balanced by a
long, heavy tail. It is classified as an allosaurid, a type of carnosaurian Predator
theropod dinosaur. It has a complicated taxonomy, and includes an
uncertain number of valid species, the best known of which is A. fragilis. The
bulk of Allosaurus remains have come from North America's Morrison
Formation, with material also known from Portugal and possibly Tanzania. It
was known for over half of the 20th century as Antrodemus, but study of the
copious remains from the Cleveland Lloyd Dinosaur Quarry brought the Adapted to
name Allosaurus back to prominence, and established it as one of the best- running
known dinosaurs.As the most abundant large predator in the Morrison
Formation, Allosaurus was at the top of the food chain, probably preying on
contemporaneous large herbivorous dinosaurs and perhaps even other
predators (e.g. Ceratosaurus). Potential prey included ornithopods, Scavenger
stegosaurids, and sauropods. Some paleontologists interpret Allosaurus as
having had cooperative social behavior, and hunting in packs, while others
believe individuals may have been aggressive toward each other, and that
congregations of this genus are the result of lone individuals feeding on the
same carcasses. It may have attacked large prey by ambush, using its upper KANHAIYA
By VISHAL 12/7/2012 35
jaw like a hatchet.

Archaeopteryx

Scientific name: Archaeopteryx
Rank: Genus
Common names: ancient wing,
Urvogel

Archaeopteryx are the earliest known flying birds and only about the size of a modern day magpie. Living around 150
million years ago, Archaeopteryx had developed flying abilities that may have evolved from gliding out of trees or simply
running along the ground. The first complete skeleton was discovered in Jurassic limestone in Germany in 1861 and is a
very important fossil, almost certainly representing the transition between reptiles and birds. This missing link shares sharp
teeth and a long bony tail with small theropod dinosaurs, and a wishbone andKANHAIYA with the birds. Lived in Jurassic 36
By VISHAL
feathers 12/7/2012
period

Archaeopteryx Behaviours
Archaeopteryx , sometimes referred to by its German name Urvogel ("original
bird" or "first bird"), is the earliest and most primitive bird known. The name
derives from the Ancient Greek ἀρχαῖοσ (archaīos) meaning "ancient", and Carnivorous
πτέρυξ (ptéryx), meaning "feather" or "wing“. Archaeopteryx lived in the Late
Jurassic Period around 150 million years ago, in what is now southern Germany
during a time when Europe was an archipelago of islands in a shallow warm
tropical sea, much closer to the equator than it is now. Similar in shape to a
European Magpie, with the largest individuals possibly attaining the size of a
raven, Archaeopteryx could grow to about 0.5 meters (1.6 ft) in length. Despite Adapted to flying
its small size, broad wings, and inferred ability to fly or glide, Archaeopteryx
has more in common with small theropod dinosaurs than it does with modern
birds. In particular, it shares the following features with the deinonychosaurs
(dromaeosaurs and troodontids): jaws with sharp teeth, three fingers with
claws, a long bony tail, hyperextensible second toes ("killing claw"), feathers Adapted to gliding
(which also suggest homeothermy), and various skeletal features. The features
above make Archaeopteryx a clear candidate for a transitional fossil between
dinosaurs and birds. Thus, Archaeopteryx plays an important role not only in
the study of the origin of birds but in the study of dinosaurs. It was named
from a feather in 1861. That same year, the first complete specimen of
Archaeopteryx was announced; this was only two years after Charles Darwin Egg layer
published On the Origin of Species, and it became a key piece of evidence in
the debate over evolution. Over the years, nine more fossils of Archaeopteryx
have surfaced. Despite variation among these fossils, most experts regard all
the remains that have been discovered as belonging to a single species,
though this is still debated.
Most of these eleven fossils include impressions of feathers—among the oldest Predator
direct evidence of such structures. Moreover, because these feathers are of an
advanced form (flight feathers), these fossils are evidence that the evolution of
feathers began before the Late Jurassic By VISHAL KANHAIYA 12/7/2012 37

Began: 142 million years ago
Cretaceous period Ended: Cretaceous-Tertiary mass
The Cretaceous ended with the extinction
most famous mass extinction in 65 million years ago
history - the one that killed the
dinosaurs. Prior to that, it was a
warm period with no ice caps at
the poles. Much of what we now
know as dry land - such as
southern England and the
midwest of the USA - was
underwater, since sea levels
reached their highest ever
during this time. The Atlantic
Ocean grew much wider as
North and South America drew
apart from Europe and Africa.
The Indian Ocean was formed at
this time, and the island that
was India began its journey
north towards Asia.
What the Earth was like

Causes of extinctions
Flood basalt eruptions Impact events


Ankylosaurs Ankylosaurus armed with thick skin, bony
plates and a club like tail

Scientific name:
Ankylosauria
Rank: Infraorder
Common names:fused lizards

Looking like reptilian armadillos, or prehistoric tanks, Ankylosaurs were heavily armoured dinosaurs with
protective plates over their head and shoulders. Some species took their protection to extremes and even had
armoured eyelids. Spikes and protrusions were common in a bid to deter predators from taking a bite. Some
ankylosaurs had a large, heavy club at the end of the tail for wielding as a weapon or, as has also been suggested,
39
for sexual selection. To carry the weight of all this heavy armour, these plant-eating12/7/2012
By VISHAL KANHAIYA
dinosaurs had very short, stout

Ankylosaurs What killed them
Ankylosauria is a group of herbivorous The Cretaceous-Tertiary
dinosaurs of the order Ornithischia. It mass extinction - also
includes the great majority of dinosaurs known as the K/T extinction
with armor in the form of bony - is famed for the death of
osteoderms. Ankylosaurs were bulky the dinosaurs. However,
quadrupeds, with short, powerful limbs. many other organisms
They are first known to have appeared in perished at the end of the
the early Jurassic Period of China, and Cretaceous including the
persisted until the end of the Cretaceous ammonites, many flowering
Period. They have been found on every plants and the last of the
continent except Africa. The first dinosaur pterosaurs.
ever discovered in Antarctica was the
ankylosaurian Antarctopelta, fossils of Behaviours
which were recovered from Ross Island in
1986. It lived in both Jurassic and
Cretaceous periods. Predation Egg
Ankylosauria was first described by Henry defense layer
Fairfield Osborn in 1923. In the Linnaean
classification system, the group is usually
considered a suborder or an infraorder. It is
contained within the group Thyreophora,
which also includes the stegosaurs,
armored dinosaurs known for their Herbivore
combination of plates and spikes. s


A pair of Torosaurus dinosaurs, that are now thought to
Horned dinosaurs be a form of triceratops

Scientific name: Ceratopsia
Rank: Infraorder
Common names: horn face

Speculation continues over the function of the wicked looking horns and grand neck frill of the larger ceratopsians such as
Triceratops. Were they for protection, display or even to control body temperature? The earliest horned dinosaurs were
quite small and got about on two legs. The four legged giants that characterise the group came later. Fossil evidence
suggests horned dinosaurs originated in what's now Asia during the Cretaceous period, spreading out and thriving as
herbivores. Many of the species are recognised from their skulls, whichVISHAL to be the part of a ceratopsian skeleton most
By
seem KANHAIYA 12/7/2012 41
likely to be preserved. Lived in the Cretaceous period.

Horned dinosaurs Triceratops
Ceratopsia or Ceratopia is a group of
herbivorous, beaked dinosaurs which thrived in
what are now North America and Asia, during
the Cretaceous Period, although ancestral
forms lived earlier, in the Jurassic. Early Behaviours
members such as Psittacosaurus were small
and bipedal. Later members, including Predation defence
ceratopsids like Centrosaurus and Triceratops,
became very large quadrupeds and developed
elaborate facial horns and a neck frill. While the
frill might have served to protect the
vulnerable neck from predators, it may also Protoceratops Herbivorous
have been used for display, thermoregulation,
the attachment of large neck and chewing
muscles or some combination of the above.
Ceratopsians ranged in size from 1 meter (3 ft)
and 23 kilograms (50 lb) to over 9 meters (30 ft) Egg layer
and 5,400 kg (12,000 lb).
Triceratops is by far the best-known
ceratopsian to the general public. It is
traditional for ceratopsian genus names to end
in "-ceratops", although this is not always the
case. One of the first named genera was Adapted to running
Ceratops itself, which lent its name to the
group, although it is considered a nomen
dubium today as its fossil remains have no
distinguishing characteristics that are not also By VISHAL KANHAIYA 12/7/2012 42

Triceratops

Triceratops drinking at a
pond

Scientific name: Triceratops
Rank: Genus
Common names: three-horned
face

Together with the bony frill behind its extraordinarily large head, the three distinctive horns of the Triceratops were
traditionally viewed as defensive weapons for this mighty herbivore. However, it is likely that they were used in courtship
and dominance displays, much as modern deer use their antlers. One of the last groups of dinosaur to evolve, Triceratops
would have shared the landscape with, and been preyed upon by, the awesome Tyrannosaurus. There is little evidence that
they ever had the spectacular battles so often depicted, however. No complete Triceratops skeleton has yet been found
and what was thought to be another horned dinosaur, Torosaurus, has recently been identified as the fully mature form of
Triceratops.

Triceratops
Triceratops is a genus of herbivorous ceratopsid dinosaur which lived during the late Maastrichtian stage of the Late
Cretaceous Period, around 68 to 65 million years ago in what is now North America. It was one of the last dinosaur genera
to appear before the great Cretaceous–Tertiary extinction event.Bearing a large bony frill and three horns on its large four-
legged body, and conjuring similarities with the modern rhinoceros, Triceratops is one of the most recognizable of all
dinosaurs and the best known ceratopsid. It shared the landscape with and was preyed upon by the fearsome
Tyrannosaurus, though it is less certain that the two did battle in the manner often depicted in traditional museum displays
and popular images. The exact placement of the Triceratops genus within the ceratopsid group has been debated by
paleontologists. Two species, T. horridus and T. prorsus, are considered valid although many other species have been
named. Recent research suggests that the contemporaneous Torosaurus, a ceratopsid long regarded as a separate genus,
actually represents Triceratops in its mature form. Triceratops has been documented by numerous remains collected since
the genus was first described in 1889, including at least one complete individual skeleton. Paleontologist John Scannella
observed: "It is hard to walk out into the Hell Creek Formation and not stumble upon a triceratops weathering out of a
hillside." Forty-seven complete or partial skulls were discovered in just that area during the decade 2000–2010. Specimens
representing life stages from hatchling to adult have been found.The function of the frills and three distinctive facial horns
has long inspired debate. Traditionally these have been viewed as defensive weapons against predators. More recent
theories, noting the presence of blood vessels in the skull bones of ceratopsids, find it more probable that these features
were primarily used in identification, courtship and dominance displays, much like the antlers and horns of modern
reindeer, mountain goats, or rhinoceros beetles. The theory finds additional support if Torosaurus represents the mature
form of Triceratops, as this would mean the frill also developed holes (fenestrae) as individuals reached maturity, rendering
the structure more useful for display than defense.

Behaviours Triceratops size

Predation defense
Herbivorous
Egg layer
Courtship display


Protoceratops Two protoceratops from a group fighting in the
desert

Scientific name:
Protoceratops
Rank: Genus
Common names: first horn
face

Were the beak and clawed legs of Protoceratops fossil remains the origin of the lion bodied, eagle headed griffin of Greek
legend? We know now that Protoceratops was an early type of horned dinosaur related to Triceratops. These herbivores
would have been about the size of sheep and may have roamed in herds, devouring the vegetation of the time. Certainly,
the finding of fossilised remains of many individuals in one place suggested herd behaviour. One of the two recognised
finds of Protoceratops fossils was infamous for having a velociraptorBy VISHAL KANHAIYA around it as if locked in battle. 45
skeleton wrapped 12/7/2012

Protoceratops Fossil Folklore
Protoceratops , (derived from Greek proto
'first', cerat‘ horn' and ‘ops’ face )is a genus
of sheep-sized (1.5 to 2 m long) herbivorous
ceratopsian dinosaur, from the Upper
Behaviours
Cretaceous Period (Campanian stage) of
what is now Mongolia. It was a member of Predation defence
the Protoceratopsidae, a group of early
horned dinosaurs. Unlike later ceratopsians,
however, it lacked well-developed horns
Protoceratops have featured it our
and retained some primitive traits not seen folklore - learn more our ancestors
in later genera. beliefs before we understood Herbivorous
Protoceratops had a large neck frill, which fossilisation and evolution.
may have served to protect the neck, to
anchor jaw muscles, to impress other
members of the species, or combinations of
these functions. Described by Walter Velociraptors work together to hunt
down a bulky Proceratops. Egg layer
Granger and W.K. Gregory in 1923,
Protoceratops was initially believed to be an
ancestor of the North American
ceratopsians. Researchers currently
distinguish two species of Protoceratops (P.
andrewsi and P. hellenikorhinus), based in Adapted to running
part by their respective sizes.In the 1920s,
Roy Chapman Andrews discovered
fossilized eggs in Mongolia that were
interpreted as belonging to this dinosaur,
but which turned out to be those of

Ceropod dinosaurs
A group of
Scientific name: Cerapoda Corythosaurus
Rank: Suborder dinosaurs on a frozen
Common names: horn foot landscape

Ceropod dinosaurs were all plant-eaters and include the horned and duck-billed dinosaurs. The secret of their success was
in their teeth. These were much more efficient at grinding up plant food than your typical dinosaur's dentition, so cerapods
were able to extract more nutritional value from their food and tackle plants that others found too tough to digest. It
wasn't until big herbivorous mammals evolved that such efficient chewing teeth were seen again on Earth.

Ceropod dinosaurs
Neornithischia is a clade of the order
Ornithischia. They are the sister group
of the Thyreophora within the clade
Genasauria. Neornithischians are united
by having a thicker layer of
asymmetrical enamel on the inside of
their lower teeth. The teeth wore
unevenly with chewing and developed
sharp ridges that allowed What killed them
neornithischians to break down tougher
plant food than other dinosaurs

Behaviours
Cretaceous-Tertiary mass extinction
Herbivorous Egg layer


Ornithopod dinosaurs Scientific name:
Ornithopoda
Rank: Infraorder
Common names: bird feet

With some of the most advanced chewing apparatus ever developed by a reptile, ornithopod dinosaurs became a most successful
group of herbivorous dinosaurs. They rapidly became a prominent feature on North America's Cretaceous landscape, until they were
wiped out by the famous Cretaceous-Tertiary, or K-T, extinction event. Early ornithopods were only about a metre long and could
probably run very fast on their hind legs. They evolved to become as large as some of the mighty sauropods, walking and grazing on
all four legs, but still using the hind legs for running and reaching up into trees. Notable ornithopods include the duck-billed
hadrosaurs and, of course, iguanodon.

Ornithopod dinosaurs
Ornithopods or members of the clade
Ornithopoda are a group of bird-
hipped dinosaurs that started out as
small, bipedal running grazers, and
grew in size and numbers until they Iguanodons
became one of the most successful
groups of herbivores in the Cretaceous
world, and dominated the North
American landscape. Their major
evolutionary advantage was the
progressive development of a chewing
apparatus that became the most Duck-billed dinosaurs
sophisticated ever developed by a
reptile, rivaling that of modern
mammals like the domestic cow. They
reached their apex in the duck-bills,
before they were wiped out by the
Leaellynasaura
Cretaceous-Tertiary extinction event
along with all other non-avian
dinosaurs. Members are known from
all seven continents, although the
Antarctic remains are unnamed, and
they are generally rare in the Southern
Hemisphere.
Muttaburrasaurus

Chromista
Chromista include
diatoms, ciliates
and their
relatives. As many
of the species in
this kingdom can
photosynthesise,
and have rigid cell
walls, they were Giant kelp viewed
once thought to from underwater
be plants. Their
members include
kelps, the water
mould that
caused the Irish
potato famine
and single-celled
organisms such as
the paramecium.

Scientific name: Chromista
Rank: Kingdom
Common names: Chromista

The Chromista are a eukaryotic supergroup, probably polyphyletic, which may be treated as a separate kingdom
or included among the Protista. They include all algae whose chloroplasts contain chlorophylls a and c, as well as
various colorless forms that are closely related to them. These are surrounded by four membranes, and are
believed to have been acquired from some red alga.

Scientific name: Iguanodon
Iguanodons Rank: Genus
Common names: iguana
tooth

Plant-eating Iguanodons were large dinosaurs capable of walking on two legs or on all four. Their outstanding feature was
a highly specialised, five-fingered hand made up of an erect and spiked thumb used for defence or perhaps foraging, three
middle fingers and a grasping fifth finger. Iguanodons were one of the first dinosaurs ever described and artistic
impressions have changed much with each new discovery. Currently, it's thought they held the head low to the ground and
their long, heavy tail in the air for balance rather than vice versa. HerdsVISHAL KANHAIYAthe different species varying in size -
By
of Iguanodon - 12/7/2012 52
flourished in Europe and North America during the lower Cretaceous period.

Iguanodons Fossil types
Iguanodon is a genus of ornithopod dinosaur that lived When they lived Trace fossils
roughly halfway between the first of the swift bipedal Jurassic period
hypsilophodontids and the ornithopods' culmination in the Cretaceous period
Behaviours
duck-billed dinosaurs. Many species of Iguanodon have been
Adapted to running
named, dating from the Kimmeridgian age of the Late
Predation defence
Jurassic Period to the Cenomanian age of the Late
Herbivores
Cretaceous Period from Asia, Europe, and North America.
Social
However, research in the first decade of the 21st century
Egg layer
suggests that there is only one well-substantiated species: I.
bernissartensis, that lived from the late Barremian to the
earliest Aptian ages (Early Cretaceous) in Europe, between
about 126 and 125 million years ago. Iguanodon's most
distinctive features were its large thumb spikes, which were
possibly used for defence against predators, combined with
long prehensile fifth fingers able to forage for
food.Discovered in 1822 and described three years later by
English geologist Gideon Mantell, Iguanodon was the second
dinosaur formally named, after Megalosaurus. Together with
Megalosaurus and Hylaeosaurus, it was one of the three
genera originally used to define Dinosauria. A large, bulky
herbivore, Iguanodon is a member of Iguanodontia, along
with the duck-billed hadrosaurs. The taxonomy of this genus
continues to be a topic of study as new species are named or Iguanodon size
long-standing ones reassigned to other genera.Scientific
understanding of Iguanodon has evolved over time as new
information has been obtained from the fossils. The
numerous specimens of this genus, including nearly
complete skeletons from two well-known bonebeds, have
allowed researchers to make informed hypotheses regarding
many aspects of the living animal, including feeding,

Macrauchenia
Scientific name:
Macrauchenia
Rank: Genus
Common names: long llama

The first Macrauchenia skeleton was actually discovered by Charles Darwin on a stop-over on his famous journey on board
The Beagle. Since then many more remains have been found in the Lujan formation in Argentina. Although this animal
looked like it should be a member of the camel family, it was actually related to a group of animals that no longer exists -
the litopterns. Its strange skull suggests that it had a muscular proboscis. Little work has been done on Macrauchenia, but
its ankle joints and shin bones seem to be adapted for extreme mobility, allowing it to twist and turn to avoid pursuers 54
at
high speed.

Macrauchenia
When they lived
Macrauchenia ("long llama",
Miocene epoch
based on the now superseded
Pliocene epoch
Latin term for llamas Auchenia,
Pleistocene epoch Sabretooths hunt prime plains
from Greek terms which literally
targets, a herd of Macrauchenia.
mean "big neck") was a long-
necked and long-limbed, three-
toed South American ungulate
mammal, typifying the order
Litopterna. The oldest fossils date
back to around 7 million years
ago, and M. patagonica
disappears from the fossil record
during the late Pleistocene,
around 20,000 years ago. M.
patagonica was the best known
member of the family
Macraucheniidae, and is known
only from fossil finds in South
America, primarily from the Lujan
Formation in Argentina. The
original specimen was discovered
Behaviours What their world was like
by Charles Darwin during the
Adapted to running Ice Age
voyage of the Beagle. In life, Social
Macrauchenia resembled a herbivores
humpless camel with a short Viviparous
trunk, though it is not closely
related to either camels or By VISHAL KANHAIYA 12/7/2012 55
proboscideans.

Scientific name: Ornithischia
Bird-hipped dinosaurs Rank: Order
Common names: Bird-hipped

A group of bird-hipped dinosaurs from England during
the Lower Cretaceous Period

Bird-hipped dinosaurs derive their name from the shape of their pelvis, which resembles that of modern birds, whose pubis
points to the rear of the animal. Unexpectedly, birds did not evolve from these dinosaurs, but from the lizard-hipped
dinosaurs, since this shape of pelvis has evolved more than once. Another distinguishing characteristic of the bird-hipped
dinosaurs was a horny beak, which they used to crop plants, much like a horse or deer uses its front teeth today. Duck-
billed dinosaurs, horned dinosaurs and armoured dinosaurs were all of the bird-hipped variety. 56

Bird-hipped dinosaurs Explore this group
Ornithischia or Predentata is an extinct Ceropod Dinosaurs
order of beaked, herbivorous dinosaurs. Armoured Dinosaurs
The name ornithischia is derived from the
Greek ornitheos (ορνιθειοσ) meaning 'of a
bird' and ischion (ιςχιον) meaning 'hip
joint'. They are known as the 'bird-hipped'
dinosaurs because of their bird-like hip
structure, even though birds actually
descended from the 'lizard-hipped'
dinosaurs (the saurischians). Being
herbivores that sometimes lived in herds,
they were more numerous than the
saurischians. They were prey animals for
the theropods and were smaller than the
sauropods.

When they lived
Triassic period
Jurassic period
Cretaceous period

Behaviours
Herbivores
Egg layer
What killed them
The Cretaceous-Tertiary mass extinction
57

Scientific name: Thyreophora
Armoured dinosaurs Rank: Suborder
Common names: shield bearers

Wuerhosaurus adult and young by a pool

While early armoured dinosaurs had bony scutes like crocodiles, later forms took armour to the extremes, evolving large
plates, spikes, clubs and carapaces. Covering yourself in heavy armour proved to be a very successful anti-predation
strategy, as armoured dinosaurs evolved during the early Jurassic and lasted right up until the mass extinction at the end of
the Cretaceous period. Though there were many variations and modifications within each type, they came in two basic
forms: the stegosaurs with their rows of spikes or plates along the spine, and the more heavily amoured ankylosaurs. 58

Armoured dinosaurs
The Thyreophora ("shield bearers", often known simply as "armored dinosaurs" - Greek: θυρεοσ, a
large oblong shield, like a door and φορεω, I carry) were a subgroup of the ornithischian dinosaurs.
They were armored herbivorous dinosaurs, living from the early Jurassic until the end of the
Cretaceous.
Thyreophorans are characterized by the presence of body armor lined up in longitudinal rows along
the body. Primitive forms had simple, low, keeled scutes or osteoderms whereas more derived forms
developed more elaborate structures including spikes and plates. Most thyreophorans had relatively
small brains for their body size.Thyreophorans include well-known suborders such as the Ankylosauria
and Stegosauria as well as lesser-known groups. Among the Ankylosauria, the two main groups are the
Ankylosaurids and Nodosaurids. In both groups, the forelimbs were much shorter than the hindlimbs,
and this was particularly exaggerated in stegosaurs. The clade has been defined as the group
consisting of all species more closely related to Ankylosaurus than to Triceratops. Thyreophora is the
sister group of the Cerapoda within the Genasauria. Ankylosaurids are noted by the presence of a large
tail club composed of distended vertebrae that have fused into a single mass. They were heavy-set and
heavily armored from head to tail in bony armor, even down to minor features such as the eyelids.
Spikes and nodules, often of horn, were set into the armor. The head was flat, stocky, with little or no
"neck", roughly shovel-shaped and characterized by two spikes on either side of the head
approximately where the ears and cheeks were. Euoplocephalus tutus is perhaps the best-known
ankylosaurid.Nodosaurids, the other family in the Ankylosauria, may actually include the ancestors of
the ankylosaurids. They lived during the middle Jurassic (approx 170 mya) on up through the late
Cretaceous (65 mya) and, while armored as the ankylosaurids, did not have a tail club. Instead, the
bony bumps and spikes that covered the rest of their body continued out to the tail and/or were
augmented with sharp spines. Two examples of nodosaurs are Sauropelta and Edmontonia, the latter
most notable for its formidable forward-pointing shoulder spikes. The Stegosauria suborder comprises
the Stegosauridae and Huayangosauridae. These dinosaurs lived mostly from the Middle to Late
Jurassic, although some fossils have been found in the Early Cretaceous. Stegosaurs had very small
heads with simple, leaf-like teeth. Stegosaurs possessed rows of plates and/or spikes running down the
dorsal midline and elongated dorsal vertebra. It has been suggested that stegosaur plates functioned
in control of body temperature (thermoregulation) and/or were usedBy VISHAL KANHAIYA 12/7/2012
as a display to identify members 59
of a species, as well as to attract mates and intimidate rivals. Well known stegosaurs are Stegosaurus

Stegosaurus
Scientific name:
Stegosaurus
Rank: Genus
Common names: roof-lizard

Although nowhere near the largest of the Jurassic dinosaurs, Stegosaurus were still about the size of a bus. Distinctive and
heavily built, they were herbivores with short forelimbs and would have walked with their small head close to the ground
and the four-spiked tail held high. The double row of plates running along the back helped control body temperature and
were probably used in display or possibly in defence against carnivorous Allosaurs. Most fossils for the three known
species, including some complete skeletons, have come from the USA,VISHAL KANHAIYA 12/7/2012 in Portugal suggests a
By
although a recent discovery 60
wider distribution.

Stegosaurus Behaviours
Stegosaurus is a genus of stegosaurid armored dinosaur from Heat tolerant
the Late Jurassic period (Kimmeridgian to early Tithonian) in Predation defense
what is now western North America. In 2006, a specimen of Herbivores
Stegosaurus was announced from Portugal, showing that they Egg layer
were present in Europe as well. Due to its distinctive tail spikes Social
and plates, Stegosaurus is one of the most recognizable
dinosaurs, along with Tyrannosaurus, Triceratops, and
Apatosaurus. The name Stegosaurus means "roof lizard"
(sometimes put as "covered lizard", but in the sense that a roof
covers a building) and is derived from the Greek ςτέγοσ-,
stegos- ("roof") and ςαῦροσ, -sauros ("lizard"). At least three
species have been identified in the upper Morrison Formation
and are known from the remains of about 80 individuals. They
lived some 155 to 150 million years ago, in an environment and
time dominated by the giant sauropods Diplodocus,
Camarasaurus, and Apatosaurus.
A large, heavily built, herbivorous quadruped, Stegosaurus had
a distinctive and unusual posture, with a heavily rounded back,
short forelimbs, head held low to the ground and a stiffened
tail held high in the air. Its array of plates and spikes has been
the subject of much speculation. The spikes were most likely
used for defense, while the plates have also been proposed as a Stegosaurus size
defensive mechanism, as well as having display and
thermoregulatory (heat control) functions. Stegosaurus was
the largest of all the stegosaurians (bigger than genera such as
Kentrosaurus and Huayangosaurus) and, although roughly bus-
sized, it nonetheless shared many anatomical features
(including the tail spines and plates) with the other
stegosaurian genera. By VISHAL KANHAIYA 12/7/2012 61

Scientific name: Tarbosaurus
Tarbosaurus Rank: Genus
Common names: alarming
lizard

Tarbosaurus was a relative of Tyrannosaurus and lived in Asia during the late Cretaceous. It has the smallest forearms of all
the tyrannosaurs known and though slightly smaller than T-rex, was still one of the larger members of the tyrannosaurid
family. It had a lightweight skeleton, which probably helped to increase its agility. Tarbosaurus bataar skeletons are
common in the rocks of the Nemegt Formation of the Gobi Desert in Mongolia

Tarbosaurus Behaviours
Scavenger
Tarbosaurus is a genus of tyrannosaurid theropod
Carnivorous
dinosaur that flourished in Asia about 70 million years ago,
Egg layer
at the end of the Late Cretaceous Period. Fossils have been
Predator
recovered in Mongolia, with more fragmentary remains
Adapted to
found further afield in parts of China. Although many
running
species have been named, modern paleontologists
recognize only one, T. bataar, as valid. Some experts
contend that this species is actually an Asian
representative of the North American genus
Tyrannosaurus; if true, this would invalidate the genus
Tarbosaurus altogether. A recreated encounter between Tarbosaurus
Tarbosaurus and Tyrannosaurus are considered to be at and a tail-clubbing Ankylosaur.
least closely related genera, if not synonymous. Alioramus,
also from Mongolia, is thought by some authorities to be
the closest relative of Tarbosaurus. Like most known
tyrannosaurids, Tarbosaurus was a large bipedal predator,
weighing more than a ton and equipped with dozens of
large, sharp teeth. It had a unique locking mechanism in its
lower jaw and the smallest forelimbs relative to body size
of all tyrannosaurids, renowned for their
disproportionately tiny, two-fingered forelimbs. Tarbosaurus and a Therizinosaurus face off in a battle of
Tarbosaurus lived in a humid floodplain criss-crossed by gigantic proportions
river channels. In this environment, it was an apex predator
at the top of the food chain, probably preying on other
large dinosaurs like the hadrosaur Saurolophus or the
sauropod Nemegtosaurus. Tarbosaurus is very well
represented in the fossil record, known from dozens of
specimens, including several complete skulls and
skeletons. These remains have allowed scientific studies By VISHAL KANHAIYA 12/7/2012 63

Theropod dinosaurs

Scientific name: Theropoda
Rank: Suborder
Common names: beast-
footed

Theropod dinosaurs were the top predators in the Jurassic and Cretaceous periods. For over 100 million years theropods
were the only large carnivores on land and included all the infamous carnivorous dinosaurs - Tyrannosaurus, Velociraptor
and Spinosaurus. However, not all theropods were predators. Some evolved away from their carnivorous origins to
consume an omnivorous or herbivorous diet. Birds are the only living descendants of the theropods.

Theropod dinosaurs What killed them
Theropods is both a suborder of bipedal The Cretaceous-Tertiary mass extinction
saurischian dinosaurs, and a clade
consisting of that suborder and its When they lived Fossil types
descendants (including modern birds). Triassic period Trace fossils
Dinosaurs belonging to the suborder Jurassic period
theropoda were primarily carnivorous, Cretaceous period
although a number of theropod groups
evolved herbivory, omnivory, and
insectivory. Theropods first appeared during Allosaurus
the Carnian age of the late Triassic period Australovenator Tyrannosaurs
about 230 million years ago (Ma) and
included the sole large terrestrial carnivores
from the Early Jurassic until at least the
close of the Cretaceous, about 65 Ma. In the
Jurassic, birds evolved from small Carcharodontosaurids Dromaeosaurs Coelophysis
specialized coelurosaurian theropods, and
are today represented by 9,900 living
species.
Among the features linking theropod
dinosaurs to birds are the three-toed foot, a Therizinosaurus
furcula (wishbone), air-filled bones and (in
some cases) feathers and brooding of the
eggs.


Scientific name: Tyrannosauridae
Tyrannosaurs Rank: Family
Common names: tyrant lizards

The family of tyrannosaurs includes the famous Tyrannosaurus rex as well as other large carnivores such as Albertosaurus
and Tarbosaurus. They evolved in the late Cretaceous and their large size made them the top predators of the time. Like
human beings, tyrannosaurs went through an adolescent growth spurt, increasing greatly in height and weight until they
approached sexual maturity. Thereafter they grew much more slowly until they reached their final size. Tyrannosaur fossils
are found in Asia and North America, through their ancestors also livedVISHAL KANHAIYA 12/7/2012
By in Europe. 66

Tyrannosaurs Tyrannosaurus rex
Tyrannosauridae (or tyrannosaurids, meaning "tyrant
lizards") is a family of coelurosaurian theropod
dinosaurs which comprises two subfamilies containing
up to six genera, including the eponymous
Tyrannosaurus. The exact number of genera is
controversial, with some experts recognizing as few as
three. All of these animals lived near the end of the
Cretaceous Period and their fossils have been found
only in North America and Asia.
Although descended from smaller ancestors,
tyrannosaurids were almost always the largest
predators in their respective ecosystems, putting them
at the apex of the food chain. The largest species was
Tyrannosaurus rex, one of the largest known land
predators, which measured up to 13 metres (43 ft) in
length and up to 6.8 tonnes (7.5 short tons) in weight.
Tyrannosaurids were bipedal carnivores with massive
skulls filled with large teeth. Despite their large size,
their legs were long and proportioned for fast
movement. In contrast, their arms were very small,
bearing only two functional digits.
Unlike most other groups of dinosaurs, very complete
remains have been discovered for most known
tyrannosaurids. This has allowed a variety of research
into their biology. Scientific studies have focused on
their ontogeny, biomechanics and ecology, among
other subjects. Soft tissue, both fossilized and intact,
has been reported from one specimen of Tyrannosaurus
rex. By VISHAL KANHAIYA 12/7/2012 67

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