I L L U S T R A T E D E N C Y C L O P E D I A D I N O S A U R S A N D P R E H I S T O R I C L I F E 9 1 1 6 1 7 3 5 3 8 1 2 4 3 7 1 1 8 0 7 9 9 1 N 8 B 7 S I 9 5 1 , . was just , the 75 cm long. EE quick hunter, a LL Compsognathus Archaeopteryx Daspletosaurus II fossil and FF ’s head was about Archaeopteryx large, flesh-eating , discovered in Germany A may have hunted by large meat-eater from TT A CC Velociraptor d AA Albertosaurus ost experts agree that birds evolved Tyrannosaurus Rex Compsognathus M e way as to maximize its gape. An eight-year- FF ld child could have squatted in its jaws. ones on a ad feathers. hem. The presence of small bumps or quill rom small dinosaurs. irst known bird, is closely related to the ndicate that it definitely # # in the 1850s, was the firstbe ever found dinosaur as to a complete skeleton. # f f raptors and may have evolved directlyt from b i h 1.5 m long. Its lower jaw wasa hinged in such o tyrannosaur family, which included the smaller have been more than one metre long. Although technically a theropod, it mostly fed on plants and termites. It was probably covered with feathers. rex Tyrannosaurus dinosaur from the Late Cretaceous. It grew up to 12 m long. Some of its saw- edged teeth were 18 cm long. rex Tyrannosaurus ambushing its prey or it may have scavenged on carrion. It belonged to the Therizinosaurus the Late Cretaceous. It grew up to 12 m long. It had a small head with a toothless beak and three gigantic, curved finger- claws. The claws may biggest of these t y r s i . l o Utahraptor t y Velociraptor s l i l A large meat-eating dinosaur A group of h a A group of meat-eating dinosaurs c e i argest of the theropods, growing up to Raptors from the Jurassic and Cretaceous periods. They had a huge curved claw onfoot, each used to slash their victims. Raptors included the five-metre-long and the two-metre-long Spinosaurus from the Cretaceous period. It was the l 18 m long. It had a largeback, sail held of up skin be on spines its projecting theropods with straight tails. Their name means “stiff tails”. They had only three digits on each hand. The group included raptors, rnithomimids, tyrannosaurs and therizinosaurs. outwards from its backbone. Tetanurans r s t n , p n e o has been i f . o b t i Ornithomimus Oviraptor o a t a Gallimimus (above) A group of fast-running and a h s A 2.5-metre-long meat-eater r m a p t r l hat it ate eggs from the nests of other eathers, which would have helped to keep e Tyrannosaurus rex Tyrannosaurus Ornithomimids dinosaurs from the Cretaceous period. found sitting on its nest with itsfolded, forelimbs like those of a bird. It probably had dinosaurs. A fossil of an Their name means “bird-mimic lizards” and refers to their ostrich-like appearance. They fed on plants and small animalsas such insects and lizards. They had longshaped beak- mouths and most species had no teeth at all. They included Struthiomimus Oviraptor from the Cretaceous period. Its name, meaning “egg thief”, refers to the theory t f both the eggs and the young warm. s a o r u f l a s l n i i t d r had c d a x o e . r Deinonychus e j d Baryonyx e l t Deinonychus (left) would work as a i w e b Velociraptor x Tenontosaurus d A tiny meat-eating Protoceratops a y A large meat-eating dinosaur n u locked in battle (above). and a eathered e Deinonychus f t n pack to bring down large dinosaurs, i One fossil find shows a One fossil such as this e i s e a own prey much larger than themselves. h k Compsognathus dinosaur from the Late Jurassic. It was about the size of a chicken andinsects preyed and on lizards. It was probably the fastest bipedal animal of all time, running at speeds of about 65 km per hour. powerful jaws and a relatively large brain. to its lethal, scythe-shaped toe-claws. These were so long that to raise them up while it ran. probably hunted in packs, in order tod bring Deinonychus from the Early Cretaceous. It was about three metres long, with a large head, Its name means “terrible claw”, and refers l r claw e d t long, curved i p Deinonychus’ s o v 0 j i , . x 0 6 w s a e 1 6 Coelophysis n s Dilophosaurus m l y and e n n An early group of theropods A small meat-eating dinosaur l A meat-eating dinosaur from the e 2 r a a h 1 n Baryonyx Cretaceous period. It had the body oflarge a carnivore, about eight metres long, but its skull was long and narrow,small, with sharp teeth, a bit like aprobably crocodile. fed It on fish, wading through the shallows and hooking them out with its long thumb-claw. Ceratosaurs that usually had horns or ridges onsnouts. their Their name means “horned lizards”. They had four digits on eachand hand a gap between their front andteeth. back They included Ceratosaurus Coelophysis from the Late Triassic. It grew upmetres to long. three It had a long, narrowand head sharp teeth, which it used tolizards eat and other small prey. It probably hunted in packs. a h h e a t t r s e SS . l or r DD p , the size p ( 13) e e c OO e Spinosaurus t r r PP v m c d OO o o Compsognathus A bird-dinosaur from the RR o o a n EE A large meat-eating dinosaur HH heropods were a group of mostly meat-eating saurischian “lizard hipped” dinosaurs. They all C C M F M a rom theropods during the Jurassic period. TT T had three toes and their name means “beast-footed”. Theropods were the first kind of dinosaur to evolve. They hadeyes large and long tails.They ran on theirstrong two back legs, leaving their arms freegrasp to or pin down their prey. Theyin ranged size from tiny of a chicken, to 18 m long Most experts believe that birds evolved f more in common with theropods. Like Jurassic period. It is the earliest known bird. Like birds, it had feathers, wingsa and small, light body. However, it had much them, it had strong jaws and sharpa teeth, long neck and stiff tail andfingers. three It clawed fed on meat, fish and insects. Allosaurus from the Late Jurassic. It grew uplong. to It 12 had m sharp teeth and threeclawed big, toes on each foot. It probably hunted in packs to bring down large prey. Archaeopteryx 4 1 ! ! ! ! ! I L L U S T R A T E D E N C Y C L O P E D I A DINOSAURS AND PREHISTORIC LIFE I L L U S T R A T E D E N C Y C L O P E D I A

First published in 2012 by Orpheus Books Ltd., 6 Church Green, Witney, Oxfordshire, OX28 4AW, England www.orpheusbooks.com

Copyright ©2012 Orpheus Books Ltd. Created and produced by Nicholas Harris, Sarah Hartley, Katie Sexton, Ruth Symons and Erica Williams, Orpheus Books Ltd. Text Ruth Symons Illustrated by Peter Dennis, Elisabetta Ferrero, Ray Grinaway, Gary Hincks, DINO SAUR S Studio Inklink, Steve Kirk, Simon Mendez, Nicki Palin, Peter David Scott Consultant Chris Jarvis, Oxford University Museum of Natural History All rights reserved. No part of this book may be reproduced, stored in a AND PREHISTORIC LIFE retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior written permission of the copyright owner. ISBN 978 1 7418 3761 9 Printed and bound in Singapore CONTENTS ABOUT THIS BOOK

ach double page contains a brief introduction, TIMELINE 6 Eexplaining the general subject, followed by key words arranged in alphabetical order. To look FIRST LIFE 8 up a specific word, turn to the index at the back of this book: this will tell you which page to go to. If you EARLY AMPHIBIANS want to learn more about a subject, take a look at the & REPTILES 10 factfile, or follow the arrows to read related entries. ORNITHISCHIANS 22 INTRODUCTION BOLD WORDS KEY WORDS AND ENTRIES FACTFILE This explains the These highlight Key words are arranged alphabetically The factfile provides extra MARINE REPTILES 12 general subject useful words that across each double page. Each entry information on the subject. Facts PREHISTORIC BIRDS & and provides some do not have their provides a short explanation of what are presented in easy to read basic knowledge. own entry. the key word means. bullet points. MAMMALS 24

Excavation The process of examining layers Relative dating A way of estimating the Sedimentary rock A type of rock that is of soil for fossils and other material age of an object by showing that it came formed by the pressing together of rock FOSSILS from the past. before or after another object. Relative fragments. These fragments, including dating relies upon stratigraphy and index sand, gravel and mud, are formed when Fossil footprint A fossilized fossils. It is less exact than absolute dating. other rock types are worn away by the Fossilized ossils are remains of once-living footprint, sometimes called an amonites in things preserved in rock. Most wind and rain. They gradually settle in sedimentary “ichnite”. Fossil footprints are a 1 2 Sediment Eroded rock fragments that are FIRST HUMANS 26 living things are eaten or rot away layers. As more layers settle on top of each rock type of trace fossil. The depth of transported by wind, water or ice and laid F other, the particles are compressed and when they die, leaving no trace. But the prints and the distance 3 4 down elsewhere. These fragments can cemented into sedimentary rock. Fossils sometimes, if animals are quickly buried, between them can tell us how cover skeletons and other once-living are only found in sedimentary rocks. their remains may turn into rock and be fast a dinosaur walked or ran, and materials, compressing over time to form F A C T F I L E preserved as fossils. After millions of how heavy it was. Footprints also rocks around them. Stratigraphy The study of rock layers. By # The word fossil comes from the Latin years of Earth movements and the show whether dinosaurs walked on estimating the order in which different word fossilis which means “dug up”. wearing away of rocks by water, wind two or four legs, and whether they lived rock layers were formed, scientists can # Most dinosaur fossil sites are in bare, and ice, some fossils may be exposed at alone or as part of a group. guess the age of the fossils found within the surface of the Earth. Fossils are the rocky areas with hills and cliffs, far from FOSSILS 28 them. Deeper layers of rock are generally roads and towns. Fossil-hunting is easiest Index fossil A common fossil that is known The fossilization of an ammonite. When it died, its main way that we can learn about older than the layers above them. while rocks are not covered by soil, trees to date back to a particular time. Index soft fleshy parts rotted or were eaten (1). Sandy dinosaurs and other prehistoric life. sediments covered the shell (2). Shell and sand and plants. Here, the fossils can be seen at fossils are used to date the layer of rock in Trace fossils Fossilized forms of life, such gradually turned into rock. The rock is lifted by Earth the surface, or dug out from just beneath. as footprints, feathers, droppings or shells. which they are found. Ammonites ( 12) and movements (3). Erosion uncovers the fossil shell (4). # It can take months or years to clean all trilobites ( 9) are excellent index fossils These fossils are important clues about the rock away from a fossil and piece the because they are abundant, easy to Petrification A fossil-forming process in how animals once lived. They are more fossils together. Missing parts are often which water dissolves an organism’s “borrowed” from another dinosaur of a identify, and are known to come from a “Sue” (above) is a fossil Tyrannosaurus discovered in common than any other type of fossil. similar type. specific period in Earth’s history. remains, replacing them with minerals, 1990 with all her bones in place next to each other. A INDEX 30 which then harden into the shape of the whole fossil dinosaur is an extremely rare find. # The study of fossilized animals is called 28 Amber Matrix The rock in which fossils form. organism itself. “Paleontology”. The study of fossilized 29 Palaeontologists (below) use picks, shovels and plants is called “Paleobotany”. Mineral A naturally occurring chemical Radiocarbon dating A way of calculating thin blades to remove the surrounding rock from a # To move fossils from a dig to a substance that is neither plant nor animal. fossil. They then number all the bones, Absolute dating A way of estimating the the age of an object by measuring how workroom or museum, they are covered record their exact positions age of an object by looking at its chemical Rocks are made up of minerals. much carbon-14 (C-14) it contains. C-14 is with plaster casings, just like a broken leg. and photograph them. make-up. The main method of absolute Mould fossil A hollow, bone-shaped hole, one form of the element carbon. It is dating is radiocarbon dating. formed when the skeleton of an animal is radioactive, meaning that it randomly changes into different elements, a process Amber A hard yellow-orange substance dissolved by water in the ground. called “decay”. All living things absorb C-14 formed when sticky tree resin is fossilized. Paleontologist A scientist who studies from the atmosphere. When they die,they FLYING REPTILES 14 It sometimes contains insects and other fossils and other signs of life from the past. stop taking in carbon, and the C-14 within small animals that were trapped inside it. Permineralization A fossil-forming process them starts to decay. Because it decays at a Cast fossil A fossil formed when minerals in which water seeps into the hollows in known rate, scientists can find out the age fill in a mould fossil. bones, plants or shells, and leaves hard of an object by measuring how much C-14 is left. This method can be used to date Coprolite Fossilized animal dung. mineral deposits in these spaces. The objects back about 70,000 years. Coprolites are a type of trace fossil. They minerals make the remains can reveal what animals ate. harder, helping to preserve them in the ground. THE DINOSAURS 16 DNA (Deoxyribonucleic acid) A chemical found inside the cells of all living things. The pattern of the DNA forms a code, which tells the body’s cells how to act. By A trace fossil studying the DNA of extinct animals, of a dinosaur scientists can work out how they are The fossil footprint related, and therefore how they evolved. skeleton of an Ichthyosaur ( 12) (right) THEROPODS 18

ARROWS PAGE NUMBER These arrows show you where to look up other Page numbers SAUROPODS 20 words mentioned in the entry. For example, are easy to find ( 26) tells you to go forward to page 26 and at the side of ( 6) tells you to turn back to page 6. the page. started (Ma) 12 Holocene 0.0117 # The first human-like animals appear Quaternary # Several ice ages ( 24) grip the world, 1 1 GEOLOGICAL TIME 1 Pleistocene 2.58 interupted by warmer periods, or interglacials

5.32 # 2 Pliocene Mammals replace reptiles as the dominant 0 he Earth is 4500 million years old. Events in the Earth’s 1 land-animals Cenozoic Miocene 23.03 # The continents drift to approximately their history are measured in what is called geological time. present positions. Mammals evolve separately on 34 A “recent” event in geological time, for example, may 3 Oligocene their own island continents, for example T N Tertiary have happened in the last million years. Geologists divide time marsupials develop in Australia. 9 A Eocene 56 # Modern families of flowering plants develop into three eons: the Archaean (“ancient”), from the origin of I # Vast areas of grassland open up, which leads to the Earth to about 2500 million years ago (Ma); the Proterozoic R P B Palaeocene 65.5 the evolution of horses and antelopes

(“first life”) to 542 Ma; and the Phanerozoic (“visible life”) to R 4

8 E C A M the present. The Archaean and Proterozoic are often referred to Late Cretaceous 89.3 # The dinosaurs become extinct at the end of the

together as the Precambrian. The Phanerozoic is subdivided Cretaceous in the K-T extinction ( 13)

5 #

into eras: the Palaeozoic (542-251 Ma), the Mesozoic (251-65 Ma) 7 Cretaceous Middle Cretaceous 130 The first grasses and flowering plants appear 6 # The sauropods ( 16) die out and the Cenozoic (65 Ma to present). The eras are split into Early Cretaceous 146 # The hadrosaurs ( 18) first appear periods, shown on the right hand page. The Tertiary and Quaternary periods are themselves divided into epochs. Late Jurassic 161 # Pangaea begins to split in two # Plants, especially conifers, become abundant A way to understand geological time is to imagine 4500 Jurassic Middle Jurassic 176 # Sauropods ( 16) grow even larger, and million years of Earth’s history taking place in just 12 hours. Mesozoic DRIFTING CONTINENTS theropods ( 14) become more powerful hunters The Precambrian would take up the first 10 ½ hours. Early Jurassic 200 # The first ornithischian ( 18) dinosaurs appear From the Cambrian “explosion” of life, to the present day The outer shell of the Earth is divided up into large slabs, called would take up 90 minutes. The dinosaurs became extinct 228 # ( 20) tectonic plates. These plates, which include both the continents Late Triassic The first dinosaurs and pterosaurs appear only nine minutes ago. The entire history of humankind # The first large marine reptiles appear( 22) 6 and the floors of the oceans, move slowly: at an average rate of would make up the very last second. Triassic Middle Triassic 245 # The first mammals appear 7 about 2.5 cm a year. Over geological time, entire continents have # Ferns dominate Triassic plant life wandered around the globe, colliding into one another, drifting Early Triassic 251 # The first turtles appear These three globes show the movement of the apart or sliding past one another. About 200 million years ago, continents over geological time. Still widely separated # The continent of Pangaea forms they came together to form a single “supercontinent” called 4000 million years ago (1), they had collided to form Permian 299 # Reptiles dominate the land Pangaea ( 39). There was no Atlantic Ocean, and the Pangaea by 250 million years ago (2). They began to # The first archosaurs ( 10) appear split apart during the Age of Dinosaurs, about Americas were jammed up against Africa and Pennsylvanian 318 # The first reptiles appear ( 10) 200 million years ago (3). Europe. Since then, the continents have split Carboniferous # Hot, steamy coal swamps ( 10) of mosses and Mississippian 359 apart, although some pieces, such as India and ferns cover parts of the Earth Asia, have collided with each other. # The first amphibians appear ( 10) We know that continental drift took Devonian 416 # The first lobefin fish appear ( 9) place because fossils of Lystrosaurus # The first insects appear (below), a Triassic reptile, have been Palaeozoic # The first plants with stems and roots appear found in lands as far apart as Africa, 443 India and Antarctica. This proves that Silurian # The first fish with jaws appear these continents were once joined # Warm, shallow seas cover much of the Earth together and have since drifted apart. # The first land plants evolve Ordovician 488 # The first coral reefs form # Sea levels were high 3 # An “explosion” of life takes place ( 8) Cambrian 542 # The first shellfish evlove # The first jawless fishes appear

Proterozoic 2500 # The first known animals develop

Precambrian Archaean 4000 # The earliest life-forms appear: bacteria 2 Hadean 4500 # The formation of the Earth 1 Plants from the Late Silurian period FIRST LIFE F A C T F I L E # No one knows how life began, but scientists think that shallow, warm water he first life on Earth appeared Anomalocaris pools at the edges of the first oceans would not on land but in the oceans. have been the ideal environment for the Life on the land was formation of chemicals that would eventually T become the building blocks of life. still not possible because # There were more than 17,000 different there was not enough Opabinia oxygen in the atmosphere, species of trilobite—more than any other known extinct creature. and lethal ultraviolet radiation was still at Pikaia Hallucigenia A marine life-form from the Silurian period The period of Earth’s history # dangerous levels. Neither factor affected The Cambrian period ended with a mass Cambrian period. It moved about on the from 443 to 416 million years ago. During extinction that wiped out many species. It life underwater. The first living things seabed on seven pairs of stilts and had a this period, the first jawed fish appeared, may have been brought about by a severe probably developed about 3800 million drop in temperature. row of defensive spines on its back to and plants with roots and stems began to years ago. The very earliest life-forms protect itself from predators. grow on land. # The first land animals were giant were simple, single-cell organisms. millipedes. They lived around 442 million Lobefins years ago. More complex life-forms did not evolve Leanchoilia A species of bony fish with Tetrapods Four-legged until 580 million years ago. fleshy lobes at the base of their vertebrates (animals fins. The lobes contain jointed with a backbone). Trilobites Marine creatures with a hard, Anomalocaris The largest and fiercest of all bones, which may have evolved into Tetrapods evolved jointed shield divided into three lengthwise the known Cambrian creatures. It was Sanctacaris legs when fish evolved to move out of the from lobefins during parts. They first appeared in the Cambrian 60 cm long, with a wide cloak-like body, water and on to the land. the Devonian period and thrived for the 250 million years. two large eyes set on stalks and a pair of Hallucigenia period. Opabinia A marine creature from the pincer-like arms. Their legs allowed them to scuttle along 8 9 Cambrian period. It had five Dunkleosteus (left) the seabed, or to paddle through the water Arandaspis One of the earliest fish. It had mushroom-like eyes and a long was a fierce predator. and could also carry food to their mouths. Cyanobacteria A type of bacteria, dating The animals of the Burgess Shale (above) no jaws, but fed by sucking in scraps of clasping “nozzle”, which it back about 2800 million years. It is one of Wiwaxia A marine creature with two rows other dead animals floating in the water. It Ediacaran fauna A group of simple, worm- used to catch its prey. the earliest life-forms for which we have Eusthenopteron (below) of dagger-like blades on its back that may first appeared in the Cambrian period and like and jellyfish-like life-forms from the “crawls” out of the fossil evidence. Like plants, cynobacteria Ordovician period The have served to ward off predators. dominated the seas for 130 million years. Ediacaran period, a part of the Precambrian water on its fins. make energy from the Sun through the period of Earth’s history that lasted from 645 to 542 million years process of photosynthesis. The spread of from 488 to 443 million ago. It is named after the Ediacara Hills in cynobacteria probably increased the years ago. During this South Australia, where many fossils from amount of oxygen in the early atmosphere. period, the first plants began this time have been found. to appear on land, and the first fish began Devonian period The period of Earth’s Eusthenopteron A long, slender lobefin to adapt and become more complex. history from 416 to 359 million years ago. from the Devonian period. It could spend During this period the first amphibians Pikaia A small, worm-like marine creature Trilobite some time out of the water, “crawling” on appeared ( 10) and fish were abundant. from the Cambrian period. It had a its fins in pursuit of insects and spiders. Two distinct types of fish emerged: those stiffening rod running the length of its These fish may have been ancestors of the Burgess Shale A layer of rocks in the Rocky with skeletons made of soft cartilage (like body, a little like a backbone. It also had amphibians ( 10). Mountains in Canada that is rich in fossils sharks), and those that had bony skeletons. muscles arranged in V-shaped segments, from the Cambrian period. It is named after Eurypterid A large scorpion-like marine similar to modern fish. It may have been Dunkleosteus A huge fish from the Late the nearby Mt. Burgess. creature from the Ordovician period. an early ancestor of the vertebrates Devonian period. It was more than nine It was about two metres long. (animals with backbones). Cambrian period The period of Earth’s metres long and, instead of teeth, its jaws history from 530 to 505 million years ago. A were lined with massive plates of bone that Evolution The process by which life-forms Precambrian The span of time from the great “explosion” of life took place at the sliced through its prey like guillotine blades. change over millions of years, gradually beginning of the Earth to 530 million years beginning of this period. The first animals It was a member of the placoderms, a adapting to make the best use of their ago. It makes up about seven-eighths of with hard parts began to appear. family of armoured, jawed fish. environment. the Earth’s history. Ichthyostega An amphibian from the Hylonomus EARLY AMPHIBIANS Devonian period with a fish-like head and tail. It may have sometimes ventured on to land, but spent most of its time in the & REPTILES water. It had fingers and toes, but its limbs were not well adapted for walking.

y 375 million years ago, Labyrinthodonts A family of extinct amphibians, the first four-legged amphibians. Their name means “maze- Edaphosaurus Banimals, had developed. toothed”, referring to the complex layers Their limbs had evolved from the strong of enamel on their teeth. They include ichthyostegalia, temnospondyls, fins of certain fish. But amphibians had to Eryops keep their skin moist, and go back to anthracosaurs and lepospondyls. water to lay their eggs (as they do today). Lepospondyls A group of small, slim About 315 million years ago, another new amphibians from the Carboniferous and group of creatures appeared. They had Permian periods. The snake-like Dimetrodon scaly skin and could reproduce on land, Ophiderpeton and Phlegethontia and the avoiding the need to return to the water. newt-like Diplocaulus and Keratopeton They were the first reptiles. Archosaurs A group of reptiles that Diapsid reptiles A group of reptiles that were all lepospondyls. Permian period The period of Earth’s Therapsids A group of synapsid reptiles evolved in the Permian period. They have two openings behind the eye socket history from 299 to 251 million years ago. from the Permian period. They were Amniotes A group of animals whose young were diapsid reptiles with powerful jaws, on the side of their skulls. This group gave Scutosaurus During this period, the climate was very distinguished by their powerful jaws and develop within a protective liquid casing bony armour and a low, sprawling gait. rise not only to the dinosaurs, but also to dry. Reptiles began to outcompete large canine teeth. They included the five- called the amnion. The first amniotes They later gave rise to the dinosaurs. modern crocodiles, lizards and snakes. amphibians as their habitats dried out. metre-long Moschops, a lumbering developed in the Cambrian. Their eggs Carboniferous period The period of Eryops A two-metre-long amphibian from plant-eater. They gave rise to the mammals. 10 could survive out of the water, meaning Scutosaurus A large armoured reptile from 11 Earth’s history from 359 to 299 million the Carboniferous period. It had a flat they could permanently live on the land. the Permian period. It was a three-metre- years ago. The first reptiles emerged skull, large eyes and nostrils on the top of long plant-eater, covered with bony spikes Anapsid reptiles A group of reptiles from during the this period. its head. It may have hunted like a modern and horns to protect it from predators. the Permian period. Unlike other reptiles, crocodile, lurking submerged in the water. Coal swamp Swamps of ferns, horsetails F A C T F I L E they did not have openings behind the eye Meganeuropsis A giant dragonfly with a Synapsid reptiles A group of reptiles with and moses that covered parts of the Euparkeria A small reptile from the Early # Giant insects flourished in the hot, socket on the side of their skulls. This one opening behind the eye socket on Earth in the Carboniferous period. Triassic. It was one of the first reptiles able wingspan of up to 75 cm. It was the largest damp forests of the Carboniferous period. group gave rise to the diapsid reptiles. each side of their skulls. They dominated When the plants died, their remains to walk on two legs for short bursts. known insect that ever lived. There were dragonflies with wingspans the Permian landscape. The earliest kinds equal to those of seagulls and centipedes Anthracosaurs An early group of sank to the bottom of the swamp and Horsetail A type of large, fern-like plant, Pangaea A huge “supercontinent” made to evolve were pelycosaurs, such as that grew up to two metres long. amphibians from the Carboniferous and turned to peat, a dark, dense soil. that dominated the coal swamps. up of all the Earth’s landmasses. It formed Dimetrodon and Edaphosaurus. # Sharks were the dominant predators in Permian periods. They had large, barrel- Over millions of years, the peat was in the Permian period when all of the the Carboniferous seas. shaped bodies and spent most of their compressed and solidified to form the Hylonomus A small, lizard-like reptile from Temnospondyls A group of amphibians Earth’s continents drifted together. # The Permian period was so dry because time on the land. rock we know as coal. the Carboniferous period. It was one of from that first appeared in the Devonian Pelycosaurs A group of large reptiles from much of the Earth’s water was “locked the very first reptiles. It was only 20 cm period. They ranged from 15 cm creatures up” in huge ice caps at the South pole. the Early Permian period. Some, such as long. Its name means “forest mouse”. to 10 m long armoured amphibians. They # Dimetrodon, had large sails on their backs. At the end of the Permian period, all had four toes on their fore-feet and five a vast number of animals were The sails were made of skin and supported on their hind-feet. wiped out by the biggest mass by thin spines sticking up from the extinction ever, referred to as the backbone. They may have helped the “Great Dying”. Scientists are unsure why it occurred, although the extreme hot reptiles to heat up and cool down. Euparkeria and dry climatic conditions across the Dimetrodon was a two-metre-long globe may have been responsible. It is carnivore, feeding on large insects and thought that 70% of all land animals and other pelycosaurs. Its relative, the three- plants, and up to 95% of all marine life- forms were wiped out. A group of Eryops relax by the water. The giant metre-long Edaphosaurus, also had a dragonfly Meganeuropsis hunts for food. sail but only ate plants. Laurasia A huge northern continent. THE AGE OF It was once part of the “supercontinent” Pangaea, but broke away during the F A C T F I L E DINOSAURS Jurassic period. It included the modern # There were dinosaurs of almost every continents of Asia, North America size, from tiny hunters no larger than a pet and Europe. cat to giants that were the biggest creatures ever to set foot on Earth. Mesozoic era The span of time in Earth’s he dinosaurs were a group of reptiles # Some dinosaurs nested in huge colonies, that lived on the land during the history from 248 to 65 million years ago. It like gannets and other birds do today, TMesozoic era (250-65 million years is divided into the Triassic, Jurassic and probably for protection against predators. ago). Unlike other reptiles, they walked Cretaceous periods. During the Mesozoic # Dinosaurs were the only reptiles ever to upright on legs held beneath their bodies. era, dinosaurs ruled the land. For this walk with their legs directly beneath them. The word dinosaur means “terrible lizard”. reason, it is sometimes known as the Modern lizards, such as the Komodo dragon (below), walk with a sprawling gait. The It refers to the terrifying appearance of “Age of Dinosaurs”. bone structure of a dinosaur’s the first dinosaur finds, which were very Ornithischians The “bird-hipped” limbs was more like that of a large, but in fact dinosaurs came in all mammal’s. It allowed dinosaurs, one of two major types of dinosaurs, such as shapes and sizes. The dinosaurs spread out Two possible causes of the K-T extinction: an Like most reptiles today, female dinosaurs laid In ornithischians (left), the dinosaur (the other were the Compsognathus (right) to walk across the world and ruled the land for 160 asteroid smashes into Earth (top) and a massive eggs. Some species made nests for their young. publc bone slanted saurischians). Ornithischians had and run more efficiently. million years until 65 million years ago, backwards. volcano erupts (bottom). Ischium backward-slanting pubic bones—the # when they suddenly died out. Extinction The dying out of a species. As well as the K-T Compsognathus Pubic lower part of the hip bone. Quadrupedal Walking on four legs. Most extinction, there were Gondwanaland A huge southern continent. bone quadrupedal dinosaurs were large animals large extinctions at the Bipedal Walking on two legs only. Some end of the Triassic It was once part of the “supercontinent” Pubic that needed all four legs to support the Ischium and Jurassic types of dinosaur were bipedal. Others bone Pangaea, but drifted away during the In most saurischians weight of their bodies. They were slower periods. could only walk on two legs for short Komodo dragon Jurassic period. It included the modern (right), the publc bone than their bipedal relatives, and had to 12 periods of time, perhaps to reach treetops 13 continents of Australia, Africa, southern slanted fowards. rely on tough hides and sheer size as or to run away. Bipedal dinosaurs were Europe, Antarctica and South America. defence against meat-eating predators. Sauropodomorphs A group of large, generally much faster than their Jurassic period The period of Earth’s Some species also developed protective plant-eating saurischian dinosaurs. quadrupedal relatives. Herbivores Plant-eating animals. history from 200 to 145 million years ago. body armour. They had very long necks and tails. The sauropodomorphs and ornithischians Carnivores Meat-eating animals. During the Jurassic period, the climate This group includes the prosauropods were all herbivores. Saurischians The “lizard-hipped” All carnivorous dinosaurs were theropods. became wetter. Plants became abundant and the sauropods. dinosaurs, one of two major types of Iridium A metal that is believed to be and dinosaurs began to grow much larger. Cretaceous period The period of Earth’s dinosaur (the others were the Theropods A group of mostly meat-eating present only in the core of the Earth and in history from 145 to 65 million years ago. K-T extinction The mass extinction that ornithischians). They had forward-jutting dinosaurs. They all had three toes. asteroids (rocky objects from space). During this time, much of the Earth was took place 65 million years ago, between Dinosaur skin (above) was similar to that of modern pubic bones—the lower part of the hip A layer of iridium discovered by scientists is Triassic period The period of Earth’s covered by shallow seas and temperatures the Cretaceous and Tertiary periods. (The reptiles. Their scales did not overlap, but were bone. Saurischians included the used as evidence that the K-T extinction separated from one another by thin areas of skin. history from 248 to 200 million years were very warm. Flowering plants, which letter K stands for the German word theropods and the sauropodomorphs. was brought about by an asteroid impact. ago. This is the period when the had evolved during the Jurassic, replaced Kreidezeit, meaning “Cretaceous”.) The extinction wiped out all dinosaurs, dinosaurs first appeared. more ancient plants, and grasses appeared. The K-T extinction: a T. rex takes its final steps. pterosaurs and marine reptiles. Most Centrosaurus’ skeleton reveals some details scientists now agree that the about its lifestyle. Flat, grinding teeth, extinction was caused by the show that it fed on tough plants. impact from an asteroid (a rocky object from space). The atmosphere would have been filled with dust, blotting out the Sun and lowering temperatures for many years. Other Its horn suggests it ideas have been suggested over the years, would fend off predators. Its neck frill may have protected its neck or such as the theory that a massive volcanic been used for display purposes. eruption could have caused the extinction. THEROPODS Baryonyx F A C T F I L E

# Tyrannosaurus Rex’s head was about 1.5 m long. Its lower jaw was hinged in such heropods were a group of mostly a way as to maximize its gape. An eight-year- meat-eating saurischian ( 13) or old child could have squatted in its jaws. “lizard hipped” dinosaurs. They all T # Compsognathus, discovered in Germany had three toes and their name means in the 1850s, was the first ever dinosaur to “beast-footed”. Theropods were the first be found as a complete skeleton. kind of dinosaur to evolve. They had large # Most experts agree that birds evolved eyes and long tails.They ran on their two Baryonyx A meat-eating dinosaur from the Compsognathus A tiny meat-eating from small dinosaurs. Archaeopteryx, the strong back legs, leaving their arms free to Cretaceous period. It had the body of a dinosaur from the Late Jurassic. It was first known bird, is closely related to the raptors and may have evolved directly from grasp or pin down their prey. They ranged large carnivore, about eight metres long, about the size of a chicken and preyed on them. The presence of small bumps or quill in size from tiny Compsognathus, the size but its skull was long and narrow, with insects and lizards. It was probably the bones on a Velociraptor fossil of a chicken, to 18 m long Spinosaurus. small, sharp teeth, a bit like a crocodile. It fastest bipedal animal of all time, running indicate that it definitely had Most experts believe that birds evolved probably fed on fish, wading through the at speeds of about 65 km per hour. feathers. from theropods during the Jurassic period. shallows and hooking them out with its long thumb-claw. Allosaurus A large meat-eating dinosaur Ceratosaurs An early group of theropods from the Late Jurassic. It grew up to 12 m that usually had horns or ridges on their Archaeopteryx long. It had sharp teeth and three big, snouts. Their name means “horned clawed toes on each foot. It probably lizards”. They had four digits on each hand Therizinosaurus A large meat-eater from hunted in packs to bring down large prey. and a gap between their front and back the Late Cretaceous. It grew up to 12 m 14 teeth. They included Coelophysis, 15 Archaeopteryx A bird-dinosaur from the long. It had a small head with a toothless Ceratosaurus and Dilophosaurus. Jurassic period. It is the earliest known beak and three gigantic, curved finger- bird. Like birds, it had feathers, wings and Coelophysis A small meat-eating dinosaur claws. The biggest of these claws may a small, light body. However, it had much from the Late Triassic. It grew up to three have been more than one metre long. more in common with theropods. Like metres long. It had a long, narrow head Tyrannosaurus rex (above) Although technically a theropod, it mostly them, it had strong jaws and sharp teeth, and sharp teeth, which it used to eat Raptors A group of meat-eating dinosaurs fed on plants and termites. It was Ornithomimids A group of fast-running a long neck and stiff tail and three clawed lizards and other small prey. from the Jurassic and Cretaceous periods. probably covered with feathers. dinosaurs from the Cretaceous period. fingers. It fed on meat, fish and insects. It probably hunted in packs. One fossil find shows a They had a huge curved claw on each Their name means “bird-mimic lizards” and Tyrannosaurus rex A large, flesh-eating Deinonychus’ s feathered Velociraptor foot, used to slash their victims. Raptors long, curved and a Protoceratops refers to their ostrich-like appearance. dinosaur from the Late Cretaceous. included the five-metre-long Utahraptor claw locked in battle (above). They fed on plants and small animals such It grew up to 12 m long. Some of its saw- and the two-metre-long Velociraptor. Deinonychus (left) would work as a as insects and lizards. They had long beak- edged teeth were 18 cm long. pack to bring down large dinosaurs, shaped mouths and most species had no Spinosaurus A large meat-eating dinosaur Tyrannosaurus rex may have hunted by such as this Tenontosaurus. teeth at all. They included Ornithomimus, from the Cretaceous period. It was the ambushing its prey or it may have Struthiomimus and Gallimimus. largest of the theropods, growing up to scavenged on carrion. It belonged to the Deinonychus A large meat-eating dinosaur 18 m long. It had a large sail of skin on its tyrannosaur family, which included the from the Early Cretaceous. It was about Oviraptor A 2.5-metre-long meat-eater back, held up be spines projecting smaller Albertosaurus and Daspletosaurus. three metres long, with a large head, from the Cretaceous period. Its name, outwards from its backbone. powerful jaws and a relatively large brain. meaning “egg thief”, refers to the theory Its name means “terrible claw”, and refers that it ate eggs from the nests of other Tetanurans A group of to its lethal, scythe-shaped toe-claws. dinosaurs. A fossil of an Oviraptor has been theropods with straight tails. These were so long that Deinonychus had found sitting on its nest with its forelimbs Their name means “stiff tails”. They had Compsognathus, to raise them up while it ran. Deinonychus folded, like those of a bird. It probably had only three digits on each hand. The a quick hunter, probably hunted in packs, in order to bring feathers, which would have helped to keep group included raptors, rnithomimids, was just down prey much larger than themselves. both the eggs and the young warm. tyrannosaurs and therizinosaurs. 75 cm long. Mamenchisaurus A typical sauropod from SAUROPODS the Jurassic period. It was 25 m long, with a huge, 15 m long neck. It had 19 vertebrae in its neck—more than any other known dinosaur. he sauropods were a group of large plant-eating saurischian or “lizard- Plateosaurus A large prosauropod from Thipped” dinosaurs ( 13). They first the Triassic period. It probably spent most emerged towards the end of the Triassic. of its time on its two powerful back legs. They had tiny heads, enormously long This allowed it to reach leaves on high necks and tails, barrel-shaped bodies and branches. It had large thumb-claws, which elephant-like legs. They used their long it could use to pull down branches or lash necks to reach leaves in the treetops or out at predators. to reach down to drink from rivers. To Prosauropods A group of plant-eating nourish their great bulk, they spent all Brachiosaurus (top) had spoon-shaped teeth, well dinosaurs from the Triassic and Early day eating. Sauropods walked on four suited to its diet of tough leaves. Seismosaurus Jurassic periods. They all had long necks (above) had peg-shaped teeth, ideal for eating legs, but may have been able to rear up and tails and small heads. Many of them softer plants and stripping leaves off brahcnes. to reach the very highest branches, or walked on two legs, but some walked on crash down to protect four. Prosauropods were once thought to Shunosaurus A sauropod from the Jurassic themselves from meat- be the ancestors of larger four-legged period. It had a short neck, and a spiky tail- eating dinosaurs. sauropods but are now considered to be a club it could swing at its enemies. distinct group. They include Plateosaurus A pair of Diplodocus move through a Jurassic Brachiosaurus A very large sauropod from Diplodocus A 27-metre-long sauropod from Titanosaurs A group of sauropods that and Riojasaurus. forest. Diplodocus could use its long neck to reach the Jurassic period. At 25 m long and 14 m the Late Jurassic. It is the longest known lived in the Late Cretaceous period. They ferns that grew on swampy patches of ground. 16 tall, it would have been able to look into dinosaur from a complete skeleton. Saltasaurus An armoured sauropod from include the largest dinosaur known, 17 the top-floor window of a four-storey- It belonged to the diplodocid family, which the Late Cretaceous. It grew to about 12 m the 18 m long Argentinosaurus. building. Its name, meaning “arm lizard”, included Apatosaurus and Seismosaurus. long and had bony studs set into the skin on its back and sides. These would have refers to the unusual feature that its Gizzard stone A pebble swallowed to help Plateosaurus forelegs were longer than its made it hard for predators to bite it. (right) with digestion. Massive plant-eaters like Amargasaurus A relatively small hind legs. Diplodocus had no chewing teeth, so they F A C T F I L E A pack of Yangchuanosaurus attack a sauropod from the Late Jurassic. It was swallowed food whole, along with gizzard Camarasaurus An 18 m long Mamenchisaurus herd. The Mamenchisaurus rear # 10 m long, with two rows of tall spines Brachiosaurus is the tallest and heaviest sauropod from the Late stones, or gastroliths. These helped to up and crash down on their attackers. They also flick dinosaur known from a complete skeleton, running down its back. These may have Jurassic. It had a relatively mash the food in the dinosaurs’ stomachs. their whiplike tails in their faces. while Diplodocus is the longest. However, Sauropods could supported skin sails which could have acted short neck and tail from studying bones of other dinosaurs, probably rear up as temperature controllers. They would some scientists think the heaviest dinosaur to eat the best compared to other also have made it look larger to predators. may have been Argentinosaurus, a leaves from sauropods. Its name, titanosaur from Cretaceous Argentina. the highest Apatosaurus A large sauropod from the meaning “chambered lizard” branches. # Most sauropods walked on their Late Jurassic. At 23 m long, it was one of refers to the hollows in its toes. They had wide feet with toes the largest land animals ever. neck and back bones. and a round heel bone cushioned by a It is often mistakenly called pad of flesh. Almost all sauropods had a thumb-claw, though no-one knows Brachiosaurus Brontosaurus, after two what this was used for. skeletons of the same # Sauropods would have needed species were accidentally unbelievably large hearts to pump blood given different names. along their long necks to their heads. Some The first to be named was scientists have suggested that sauropods called Apatosaurus so it kept may have had as many as eight hearts in their chest and neck, each pumping blood this name. from one heart to the next. Ornithopods A group of plant-eating ORNITHISCHIANS dinosaurs that could move about on two feet. Some, such as Hypsilophodon, were small, fast runners, while others, such as Iguanodon, were large and slow. he ornithischians were a group of plant-eating dinosaurs that first Pachycephalosaurus A five-metre-long Tappeared in the Jurassic period. plant-eater from the Late Cretaceous. The They were one of the two major groups males probably used their thick, rounded of dinosaurs—the other was the skulls to intimidate rival males. saurischians ( 13). The ornithischians had Parasaurolophus A large plant-eating strong jaws and teeth, well-suited to dinosaur from the Late Cretaceous. chewing tough plant material. They came It had a long crest curving backwards in all shapes and sizes. Many ornithischians from the top of the skull. This was used had plates, horns, armour or spikes, to amplify calls, for example to warn the probably for defensive purposes. herd of approaching predators. Stegosaurus An armoured dinosaur from Anklyosaurus defended itself with its tail club. Ankylosaurs A group of armoured the Jurassic period. It grew up to nine dinosaurs from the Jurassic and Cretaceous metres long, and had two rows of flat, periods. They were covered with rows of bony plates sticking out of its back. These F A C T F I L E Maiasaura babies being fed by their mother Lambeosaurus A large duck-billed dinosaur bony plates and spikes and had large, probably helped to control from the Late Cretaceous. It had a hollow # Some hadrosaurs had more than 1000 barrel-shaped bodies, supported by four Euoplocephalus A large ankylosaur from its body temperature. Each bony crest on its head, which may have teeth, with new ones continually replacing sturdy legs. The group included the Late Cretaceous period. It had large plate was filled with blood old, worn ones. These dinosaurs could both amplified warning calls to other members Ankylosaurus, Euoplocephalus and spines on its shoulders and a heavy club at vessels that would take crop and grind up the toughest of plant of its herd. Different types of lambeosaurs 18 Scelidosaurus. Ankylosaurus could swing its the end of its tail. It could grow up to seven in or give off heat, material in their mouths. This meant that, 19 had differently-shaped crests. unlike sauropods, hadrosaurs would not have bony tail-club into an attacker. metres long. depending on had to consume so much plant material or whether the dinosaur swallow pebbles to help with digestion. Ceratopsians A group of plant-eating Hadrosaurs A group of plant-eating Stegosaurus needed to warm up in dinosaurs with large neck-frills and parrot- dinosaurs from the Late Cretaceous. #It was once thought that some crested the morning sun or cool hadrosaurs like Parasaurolophus were like beaks. Their name means They are sometimes called duck-billed down later in the day. The acquatic animals. The crest was thought to “horned-faces”. Early types, such as dinosaurs because their mouths were wide plates could also have been used in have acted as a snorkel, allowing the Psittacosaurus were small and walked on and flat like a duck’s. Some hadrosaurs dinosaurs to breathe under water. courtship display by males. two legs. Later types, such as had shapes of hollow bone on their head, # Hypsilophodon was once thought to be a Triceratops were larger and which amplified their calls. Hadrosaurs Protoceratops A two-metre-long Styracosaurus A six-metre-long tree-dweller, like the modern tree kangaroo walked on four legs. included Maiasaura, Parasaurolophus ceratopsian from the Cretaceous. Its name ceratopsian with a nose horn and six long whose build it was said to resemble. and Lambeosaurus. means “first horned face”, and refers to bony spikes extending from its neck-frill. 1 1 Parasaurolophus the fact that it was one of the earliest Its name means “spiked lizard”. 2 Pachycephalosaurus Hypsilophodon A two-metre-long dinosaur ceratopsian dinosaurs. 3 Corythosaurus from the Cretaceous period. It had a horny, Triceratops A nine-metre-long plant-eater Triceratops toothed beak and ran quickly on two long, Scelidosaurus An armoured dinosaur from from the Late Cretaceous. It had two long slender legs. It moved in herds, nibbling on the Early Jurassic. It was about four horns on its forehead and a shorter Maiasaura A plant-eating dinosaur from low-growing plants. metres long, and covered in bony studs, horn on its nose. Its name means the Late Cretaceous. It had a flat snout which ran down its back and tail. These “three-horned face”. It also had a Iguanodon A large plant-eating dinosaur and toothless beak. Maiasaura means studs would have protected it from the neck frill made of solid bone, which from the Early Cretaceous. It could grow “good mother lizard”. This is because the 2 teeth and claws of meat-eaters. may have been used for display in up to nine metres long. It walked on first fossil remains of Maiasaura were courtship, to protect the back of its four legs but probably ran on two. discovered alongside those of nests, egg- Scute A bony lump found on the skin of neck or make it look bigger. Its most distinctive feature was a shells and hatchlings. This was the first some dinosaurs. Scutes were set into the 3 long, spiked thumb, which it evidence that some dinosaurs raised and skin in rows. They protected dinosaurs Iguanodon might have attacked a meat- probably used as a defensive weapon. fed their young. from the teeth and claws of predators. eater with its thumb spike. Eudimorphodon A small pterosaur from Ornithocheirus A pterosaur from the Pteroid bone A bone found only in the Tapejara A medium-sized pterosaur from FLYING the Late Triassic with a wingspan of Cretaceous period with a wingspan of wrist joints of pterosaurs. It pointed the Cretaceous period. Tapejara had a just under a metre and a long, 2.5 metres. It had a “keel” at the end of its forwards and inwards to support the short tail and a wingspan of up to five pointed tail. It used its sharp toothed beak, which may have helped it pterosaur’s wings and assist with steering metres. There was a large, bright crest on REPTILES teeth to eat fish. to trap fish or crush crustaceans. in flight. its head, made of skin stretched across two bones. This crest may have been used Quetzalcoatlus for courtship displays, to attract a mate or lying reptiles, known as pterosaurs, A large pterosaur ward off rivals. first took to the air in the Triassic Ornithocheirus (below) from the Late Fperiod. They dominated the skies Cretaceous. With a for nearly 100 million years. They ranged wingspan of about 11 m, it was in size from a few centimetres to nearly the largest known flying creature of Tupuxuara 11 m across. Their wings were formed all time. It had a long, toothless jaw, a from sheets of skin stretched between curved neck and a hard crest on its head. Quetzalcoatlus lacked the muscle power their fourth fingers and their bodies. Pteranodon A Cretaceous to take off by running quickly. Instead it Their bones were hollow, making them pterosaur with a wingspan of up to nine light enough to fly. Many had powerful, have may become airborne by launching Rhamphorhynchus (above) had sharp teeth and metres. Pteranodon had a furry body and itself from a cliff edge. toothed beaks, perfect for seizing fish. could easily catch fish from just below the short tail. It probably fed like a modern There were two main types of pterosaur: water’s surface. pelican, scooping fish from the water and Rhamphorhynchs One of the two main short-tailed pterodactyls and long-tailed swallowing them whole. types of pterosaur. Their name means rhamphorhynchs. Quetzalcoatlus “beak snout”. Rhamphorhynchs had long tails, ending in a diamond-shaped flap of skin. Their long, narrow jaws were Actinofibril filled with sharp teeth that pointed 20 The fibre found in pterosaurs’ wings. outwards. They first appeared in the 21 Several layers of actinofibrils stretched Triassic period. They included across the wings, stiffening them, thus Rhamphorhynchus, Eudimorphodon Pterodactyls One of making flying easier. and Dimorphodon. the two main types of Anurognathus A small pterosaur pterosaur. Their name from the Triassic period. With a means “wing finger”. wingspan of 50 cm, it was the smallest Dimorphodon A small Pterodactyls had very known pterosaur. It had a pterosaur from the Early Jurassic short tails. They first short tail, long skull and period with a long, pointed tail and appeared during the Middle Jurassic. sharp, pointed teeth. F A C T F I L E wingspan of 1.4 m. Like all members of Pterodactyls included Pteranodon, It probably ate # Pteranodon’s long wings were ideally the rhamphorhynch family, it had a Pterodactylus, Quetzalcoatlus, insects. suited for gliding on air currents above the disproportionately large head, which was Dsungaripterus and Tupuxuara. oceans, just as an albatross flies today. It also deep and narrow like a puffin’s. For a coud travel for many kilometres without Pterodactylus A small pterosaur from the needing to flap its wings, a flight pattern male, the size and colouring of its head Late Jurassic with a wingspan of known as “dynamic soaring”. may have played a crucial role in between 50 cm and one metre. # Quetzalcoatlus lacked the muscle power impressing a female during courtship. It preyed on fish and small to take off by running quickly. Instead it Dsungaripterus A pterosaur from the animals, but also scavenged on have may become airborne by launching itself from cliff edges. Early Cretaceous period with a wingspan carrion. While on land, it got of about three metres. It had a bony crest about on all fours, using its # Many pterosaurs had huge eye sockets, claws to help it climb. indicating that their eyes were large and on its snout and an upward-curving beak, their eyesight sharp. This would have probably used to prise shellfish off rocks. enabled them to spot prey on land or at sea Tapejara (above) Blunt teeth at the back of its jaws would Pteranodon sternbergi from high in the air. have been used to break shellfish open. Elasmosaurus A large plesiosaur from MARINE the Late Cretaceous. Its long, snaky Kronosaurus neck measured about eight Eurhinosaurus metres and was nearly half of REPTILES its body length. Elasmosaurus may have used its long neck to catch hile the dinosaurs ruled the fish by surprise. and, other kinds of reptiles Eurhinosaurus, It could catch the a type of ichthyosaur with dominated the seas and W fastest fish of its time. sideways-pointing teeth oceans. These marine reptiles had scaly skin, sharp teeth, four flippers and a Ichthyosaurs tail. Most were fierce hunters, chasing A group of marine reptiles prey, such as fish, squid and shellfish. with a body shape similar to Like the dinosaurs, the sea reptiles that of modern dolphins. The Fish breathed air, which meant that they name ichthyosaur means “fish Squid regularly had to come to the water’s lizard”. The ichthyosaurs lived through surface. Marine reptiles first emerged in the Jurassic and Cretaceous periods. They Ammonite the Triassic period. varied greatly in size: Mixosaurus was only Ichthyosaurus was abundant during the Jurassic, A Kronosaurus pursues a shoal of fish one metre long, Ichthyosaurus was about when shallow waters covered much of the Earth. Ammonite A Cretaceous cousin of the two metres long, while Shonisaurus grew modern octopus and squid. Ammonites to more than 21 m. They all had large Liopleurodon The largest of the pliosaurs. Placodonts A group of small, armoured Plesiosaurs A group of plesiosauroids protected their soft bodies inside hard, eyes, smooth, streamlined bodies and At 25 m long, it was the biggest predator marine reptiles from the Triassic period. with long, snake-like necks, small heads coiled shells. They snared their tiny prey sharp, closely-set teeth. in the Jurassic seas. Members of this family include Placodus, a and four large flippers. They roamed the F A C T F I L E with their long tentacles. They were a two-metre-long reptile, with a short neck seas from the Triassic to the # 22 Kronosaurus A 10-metre-long pliosaur Mosasaurs A family of giant sea lizards Liopleurodon was the largest carnivore 23 favourite food of marine reptiles such as and long legs, and Henodus, a bony-plated Cretaceous. Plesiosaurs of all time. from the Cretaceous. It had a huge head, from the Cretaceous period. Some the ichthyosaurs. reptile, quite similar to modern turtles. included Plesiosaurus and # about a quarter of its whole body length, mosasaurs could grow up to 15 m long. The name Kronosaurus means “lizard of Elasmosaurus. Kronos”. Kronos was the Greek god of time They had huge teeth and long, strong Plesiosauroids A group of large marine Champsosaurus A two-metre-long, and a short neck. It preyed on turtles, who ate his five children as they were born crocodile-like marine reptile from the plesiosaurs, fish, ichthyosaurs, squid jaws. They probably preyed on fish and reptiles with four long, paddle-like in order to keep power for himself. Plesiosaurus other marine reptiles, though some flippers. Plesiosauroids were divided into Cretaceous period. Like modern and ammonites. # The name Plesiosaurus means “near crocodiles, it had a long snout lined with species may have eaten shellfish. two groups: the long-necked plesiosaurs, lizard”. It was given this name in 1821, to sharp teeth, four short legs and a long tail. Elasmosaurus hunting a shark Members of the family include and the short-necked pliosaurs. show that it was more closely related to Platecarpus, Tylosaurus and Mosasaurus. land reptiles than to Ichthyosaurus, whose Pliosaurs A group fossil had also been found in nearby rocks. Nothosaurs A group of Triassic marine of plesiosauroids with # Ichthyosaurus is one of the few reptiles with long necks and tails. short necks and huge, prehistoric animals whose fossils contain Nothosaurs ranged in size from 60 cm to evidence of skin colour. Pigment cells that powerful jaws. They were four metres long. They had were preserved suggest that Ichthyosaurus the top predators of the legs and claws adapted for had a smooth, scale-less, skin that was dark Jurassic seas and fed on red or brown in colour. living on land as well as anything from small fish to flippers suited for swimming, so # The ichthyosaur Temnodontosaurus had other marine reptiles. Members the biggest eyes of any animal that they lived both on land and in the sea. of the group included Kronosaurus ever lived. They were about Like modern seals, nothosaurs probably and Liopleurodon. 26 cm across. dived to catch fish, then dragged themselves on Teleosaurus A crocodile-like to the shore to rest. reptile from the Middle Henodus Members of this Cretaceous. It had a long slim body (left), a group include Nothosaurus, Lariosaurus, but, unlike modern crocodiles, it placodont from Ceresiosaurus and Pistosaurus. probably lived in the open ocean. the Late Triassic Shrew-like Alphadon was Hyaenodon A flesh-eating, cat-like predator Indricotherium was the largest land Indricotherium one of the first mammals. from the Eocene. It measured up to three mammal ever. Andrewsarchus was PREHISTORIC the largest known flesh-eating F A C T F I L E metres long and had strong jaws with mammal that ever walked on land. Palaeocene BIRDS & sharp, knife-like teeth. # Complete woolly mammoth carcasses, epoch The span preserved in ice, are still being found today. Ice age A period when the Earth’s of time in Earth’s temperature drops significantly and ice # Today’s climates are generally cooler MAMMALS history from 65.5 to 56 than on many occasions in prehistory, so it sheets spread out from the poles. It is not million years ago. Most is quite possible that we are living through quite certain what causes this to happen. animals from this period an interglacial. Another ice age may one The last ice age occurred in the Pleistocene day grip the world. y the time the dinosaurs became were forest-dwellers. extinct, several different groups of epoch, starting about 20,000 years ago. # By the beginning of the Tertiary period, Pleistocene epoch The the continents had drifted to mammals had already evolved Diatryma A two-metre-tall bird from the Indricotherium A massive plant-eater from B span of time in Earth’s approximately their present positions, around the world. The first mammals Eocene epoch. It could not fly, but hunted the Eocene and Oligocene epochs. history from 2.5 million although North and South America were evolved during the Early Jurassic. They on the ground, using its enormous, bone- It measured five metres high at the still separated. Each continent, with the years ago to 12,000 were furry, warm-blooded animals that crushing beak to crunch up mammals, shoulder, making it the largest land exception of Australia and Antarctica which years ago. It was a were still linked together, had become an give birth to live young and suckled them including small, primitive horses. mammal ever. It used its flexible lips and time of many ice ages. isolated landmass. This meant with milk. But while dinosaur predators tusk-like teeth to strip leaves from trees. Eocene epoch The span of time in Earth’s that early mammals were about, they remained tiny, shrew-like Human (to scale) Andrewsarchus Quaternary period A period of Earth’s history from 56 to 34 million years ago. evolved separately on animals, venturing out of their burrows history from 1.8 million years ago to the their own island During this time, the climate was warm and Mammoth A large, elephant-like animal only at night. The extinction of the present. It followed the Tertiary period continents. tropical rainforest was widespread, even at from the Pleistocene epoch. They only ate dinosaurs enabled mammals to become and includes the Pleistocene and the poles. grass. Mammoths roamed the Earth until the dominant land animals. Birds also Sabre-toothed cat about 10,000 years ago. They may have Holocene epochs. developed into a wide variety of species, Eohippus A sixty-centimetre-long started to die out because of climate Sabre-toothed cat A two-metre-long cat including some terrifying predatory giants. prehistoric horse from the Eocene epoch. 24 change. Prehistoric humans then hunted from the Eocene and Pleistocene. It had Warm-blooded Warm-blooded animals are 25 Gigantopithecus A three-metre-tall ape that them to extinction. The woolly mammoth huge canine teeth at the front of its kept warm by energy taken from food. Andrewsarchus A huge flesh-eating lived in the forests of the Pleistocene. was a species from the far north with a mouth and probably hunted in packs. They can maintain their temperature mammal from the Eocene epoch. It was shaggy coat and long, curved tusks regardless of their surroundings. four metres long and had a skull nearly Glyptodon A large armoured mammal from Tertiary period The period of Earth’s one metre long. It may have been more of the Pleistocene epoch. It looked a lot like a Mastodon A mammal with tusks, trunks and history from 65 to 1.8 million years ago. Woolly rhinoceros A large, woolly, a scavenger than a hunter. Andrewsarchus modern armadillo. thick hair. Mastodons roamed the Earth During this period, mammals replaced rhinoceros-like animal from the was the largest known flesh-eating Diatryma snatching a primitive horse. from the Oligocene to the Pleistocene. reptiles as the dominant group of animals. Pleistocene epoch. Holocene epoch The span of time in land mammal. They were slightly smaller than mammoths, Earth’s history that started 12,000 years Interglacial A period between two ice and had teeth adapted to eating leaves. ages when the Earth’s climate warms up. A scene from the Miocene ago and continues to this day. A woolly mammoth and its young. It will epoch (below) Megatherium A six-metre-long sloth from be 10 years until the young mammoth is the Pleistocene epoch. It probably moved the size of its mother. Deinotherium about the ground on all fours. Miocene epoch The span of time in Earth’s Telicomys history from 23 to 5 million years ago. During this period, vast areas of grassland started to appear, leading to the evolution of horses and antelopes, as well as dogs, cats and hyenas to prey on them. Oligocene epoch The span of time in Earth’s history from 34 to 23 million years ago. During this time, the climate began to cool. Ice caps formed at the poles and forests were replaced by more open woodland. Hominids A family of human-like FIRST creatures that includes humans and their immediate, bipedal ancestors. F A C T F I L E HUMANS Hominoids A family of primates, that # Modern humans share about 96% of their includes humans and their ancestors, DNA with apes, such as chimpanzees. as well as modern chimpanzees, # A site that has provided a great deal of cientists know that humans, apes gorillas and orangutans. The evidence about early humans is La Sima de los Huesos (the Pit of Bones) in northern and monkeys all share a common hominoids are sometimes called Spain. Here the remains of at least 32 Sancestor but they have not yet the “great apes”. The first humans, dating to 400,000 years ago, have hominoids date to around been found at the bottom of a 15-m shaft. identified which species that was. Aegyptopithecus However, of all its descendents, only the seven million years ago. The humans may have been ancestors of the Neanderthals. human-like creatures, or hominids, Homo erectus An extinct species of developed the ability to walk upright and # Humans arrived in North America hominid that lived between 1.8 million and between 35,000 and 15,000 years ago. on two feet. The first hominids probably 400,000 years ago. Its name means They crossed from Asia at a time when the appeared over five million years ago. “upright man”. It grew to the same size as Bering Sea, which divides the two Modern humans, Homo sapiens, did not modern humans, but had jutting brows continents, was dry land. They then spread appear until relatively recently: about through the Americas, reaching the southern unlike our own. It lived and hunted in tip of South America 11,000 years ago. 125,000 years ago. groups, using basic stone tools and cooking over a fire. It originated in Africa Neanderthal hunters trap a huge woollly Homo sapiens Modern-day humans. Its Aegyptopithecus An extinct ape that Australopithecus but spread to Asia. mammoth ( 25) in a pit. name means “wise man”. Homo sapiens Out-of-Africa theory The widely-accepted lived in Egypt 33 million years ago. Homo ergaster An extinct species of Homo heidelbergensis An extinct species appeared about 250,000 years ago. Their theory that all modern humans are It was about 1.2 m long and walked on hominid that lived in Africa between 1.9 of hominid that lived in Europe between brains were larger than any of their descended from a group of Homo sapiens four legs. It is believed to be an ancestor and 1.4 million years ago. It had thin 780,000 and 200,000 years ago. It stood ancestors, apart from the Neanderthals. that left Africa about 70,000 years ago. 26 of today’s Old World monkeys—monkeys 27 bones and a low forehead. Its about 1.8 m tall and hunted using basic They used tools, hunted large game, and from Africa and Asia with relatively short, Primates A group of mammals ( 24) that name, meaning “work person”, tools made of stone or bone. Evidence of created works of art such as cave paintings. inflexible tails and nostrils that are very includes humans, apes and monkeys. refers to its use of stone tools. group hunting suggests that Homo close together. Land bridge A small strip of land that joins Primates have large brains, flexible heidelbergensis could communicate with two larger land-masses. Land bridges, fingers and toes, and eyes at the front Australopithecus An extinct family of apes each other, probably using gestures. formed as the continents shifted, allowed of their heads. that lived in Africa between four and two Homo heidelbergensis was probably the early humans to move to lands such as million years ago. Most species were descended from Homo ergaster and was the Americas, Australia and Japan. about one metre tall, with long likely to be the ancestor of both arms, short legs and a small Neanderthals and Homo sapiens. Neanderthals brain. They looked ape- (Homo neanderthalensis) like but probably Homo A family of A species of Homo that first walked upright. Fossils hominids, appeared in Europe and the of several kinds, distinguished by their near East more than 250,000 including afarensis, large brains and years ago. The Neanderthals had anamensis, africanus upright stance, as well short, muscular bodies, and garhi, have been as their use of tools, overhanging brows and heavy, art and language. The discovered. Some Homo habilis using a rock to smash open bones. The hammer (left) was carved from a deer’s antler. chinless jaws. Their brains were may have been first known was the It was used to make hand-axes (right) from flints. larger than those of modern Modern human ancestors of species Homo habilis. Homo habilis An extinct species of hominid humans. They lived in groups and humans. that lived in Africa two million years ago. Homo rudolfensis An extinct species of hunted wild animals. They died Homo habilis Its name means “handy man”. Homo habilis hominid that lived in Africa 2 million years out about 30,000 years ago, made simple tools by striking one stone ago. About 1.2 m tall, it had a bigger brain possibly because of against another to make a sharp edge. It was than any previous hominid. It made rough competition for food with probably a scavenger rather than a hunter. tools and possibly lived in simple shelters. Homo sapiens. Neanderthal Excavation The process of Relative dating A way of estimating the Sedimentary rock A type of rock that is OSSILS examining layers of soil for fossils age of an object by showing that it came formed by the pressing together of rock F and other material from the past. before or after another object. Relative fragments. These fragments, including dating relies upon stratigraphy and index sand, gravel and mud, are formed when Fossil footprint A fossilized fossils. It is less exact than absolute dating. other rock types are worn away by the Fossilized ossils are the remains of once-living footprint, sometimes called an amonites in wind and rain. They gradually settle in sedimentary things preserved in rock. ichnite. Fossil footprints are a type 1 2 Sediment Eroded rock fragments that are layers. As more layers settle on top of each rock Most living things are eaten or rot of trace fossil. The depth of the transported by wind, water or ice and laid F 3 4 other, the particles are compressed and away when they die, leaving no trace. prints and the distance between down elsewhere. These fragments can cemented into sedimentary rock. Fossils But sometimes, if animals are quickly them can reveal how fast an cover skeletons and other once-living are only found in sedimentary rocks. buried by sediments, their remains may animal walked or ran, and how materials. This is the first stage in the F A C T F I L E turn into rock and be preserved as heavy it was. Footprints also show formation of fossils. Stratigraphy The study of rock layers. By # The word fossil comes from the Latin fossils. After millions of years of Earth whether an animal walked on two estimating the order in which different word fossilis, which means “dug up”. movements and the wearing away of or four legs, and whether it lived rock layers were formed, scientists can # Most dinosaur fossil sites are in bare, rocks, some fossils may come to be alone or as part of a group. guess the age of the fossils found within rocky areas with hills and cliffs, far from exposed at the surface of the Earth. them. Deeper layers of rock are generally Index fossil A common fossil that is known The fossilization of an ammonite. After it dies, its soft roads and towns. Fossil-hunting is easiest Fossils are the main way that we can older than the layers above them. where rocks are not covered by soil and to date back to a particular time. Index fleshy parts rot or are eaten (1). Sandy sediments learn about dinosaurs and other cover the shell (2). Shell and sand gradually turn into plants. Here, the fossils can be seen at the fossils are used to date the layer of rock in Trace fossil The fossilized form of objects prehistoric life forms. rock. The rock is tilted by Earth movements (3). surface, or dug out from just beneath. such as feathers, footprints, droppings or which they are found. Ammonites ( 22) and Erosion reveals the fossil shell (4). # It can take months or years to clean all trilobites ( 9) are excellent index fossils shells. These are important clues about the rock away from a fossil and fit the because they are abundant, easy to Petrification A fossil-forming process in how animals once lived. They are more various pieces together to form a skeleton. identify, and are known to come from a which water dissolves an organism’s “Sue” (above) is a fossil Tyrannosaurus rex common than any other type of fossil. Missing parts are often “borrowed” from remains, replacing them with minerals. discovered in 1990 with all her bones in place next another dinosaur of a similar type. specific period in Earth’s history. to each other. A complete fossil dinosaur is an These then harden into the shape of the # The study of fossilized animals is called extremely rare find. 28 An insect Matrix The rock in which fossils form. organism itself. “Palaeontology”. The study of fossilized 29 trapped in amber Palaeontologists (below) use picks, shovels and plants is called “Palaeobotany”. Mineral A naturally occurring solid Radiocarbon dating A way of calculating thin blades to remove the surrounding rock from # To move fossils from a dig to a substance that is neither plant nor Absolute dating A way of estimating the the age of an object by measuring how a fossil. They then number all the bones, workroom or museum, they are covered age of an object by looking at its chemical animal. Rocks are made up of minerals. much carbon-14 (C-14) it contains. C-14 is a record their exact positions with plaster casings, just like a broken leg. and photograph them. make-up. The main method of absolute Mould fossil A hollow, bone-shaped hole, special form of the element carbon. It is dating is radiocarbon dating. formed when the skeleton of an animal is radioactive, meaning that it regularly changes into different elements, a process Amber A hard yellow-orange substance dissolved by water underground. called radioactive decay. All living things formed when sticky tree resin is fossilized. Palaeontologist A scientist who studies absorb C-14 from the atmosphere. When It sometimes contains insects and other fossils and other signs of life from the past. they die,they stop taking in carbon, and the small animals that were trapped inside it. Permineralization A fossil-forming process C-14 within them starts to decay. Because it Cast fossil A fossil formed when minerals in which water seeps into the hollows in decays at a known rate, scientists can find fill in a mould fossil. bones, plants or shells, and leaves hard out the age of an object by measuring how much C-14 is left. This method can be used Coprolite Fossilized animal dung. mineral deposits in these spaces. The to date objects back about 62,000 years. Coprolites are a type of trace fossil. They minerals make the remains can reveal what animals ate. harder, helping to preserve them in the ground. DNA (Deoxyribonucleic acid) A chemical found inside the cells of all living things. The pattern of the DNA forms a code or blueprint for how the body’s cells are built. A trace fossil By studying the DNA of extinct animals, of a dinosaur scientists can work out how they are The fossil footprint related, and therefore how they evolved. skeleton of an Ichthyosaur ( 22) (right) Carboniferous period Eohippus 24 Homo rudolfensis 27 marine reptile 7, 12, palaeontologist 28-29 reptiles 6-7, 10-13, Triassic period 6-7, 10, 13, 7, 10-11 Eryops 10 Homo sapiens 26-27 22-23 Palaeozoic era 6-7 20-23, 25 14, 16-17, 20-23 INDEX carnivores 12 Eudimorphodon 20-21 humans 7, 25, 26-27 Mastodon 25 Pangaea 6-7, 11, 12-13, rhamphorhynchs 20-21 Triceratops 18-19 cast fossil 28 Euoplocephalus 18 Hyaenodon 24 matrix 28 Parasaurolophus 18-19 Rhamphorhynchus 20-21 trilobites 7, 9, 28 Cenozoic era 6-7 Euparkeria 11, 19 Hylonomus 10 Meganeuropsis 11 pelycosaurs 11 rhinoceros, woolly 25 Tupuxuara 21 Centrosaurus 12 Eurhinosaurus 23 Hypsilophodon 18-19 Megatherium 25 Pennsylvanian 7 Riojasaurus 17 Tylosaurus 22 A ceratopsians 18-19 Eurplocephalus 18 Mesozoic era 6-7, Permain period 7, 10-11 Tyrannosaurus rex 13, ceratosaurs 14 Eurypterid 8 12-13 permineralization 28 15, 19 absolute dating 28-29 Ceratosaurus 14 Eusthenopteron 8-9 Miasaura 18 petrification 28 actinofibril 20 Ceresiosaurus 22 evolution 8 I mineral 28 Phanerozoic eon 6 Aegyptopithecus 26 Champsosaurus 22 excavation 28 ice age 7, 24-25 Miocene epoch 7, Phlegethontia 11 S Albertosaurus 15 chimpanzee 26-27 extinction 12, 24 ichnite 28 24-25 Pikaia 9 sabre-toothed cat 25 UV Allosaurus 14 climate 24-25 ichthyosaurs 22-23, 28 Mississippian 7 Pistosaurus 22 Saltasaurus 17 Utahraptor 15 Alphadon 24 coal swamp 7, 10 Ichthyosaurus 22-23 Mixosaurus 22 placoderm 8 saurischians 13, 14, Velociraptor 14-15 Amargasaurus 16 Coelophysis 14 Ichthyostega 11 monkeys 26 placodonts 23 16-18 volcano 12-13 amber 28 Compsognathus 13, 14-15 ichthyostegalia 11 Mosasaurus 22 Placodus 23 sauropodomorphs 12-13 ammonite 22-23, 28-29 F continent 6, 11 Iguanodon 18-19 Moschops 11 Platecarpus 22 sauropods 7, 16-17 amniotes 10 first life 8-9 coprolite 28 index fossil 28-29 mososaurs 22 Plateosaurus 16-17 Scelidosaurus 18-19 amphibians 7, 8, 10-11 fish 7, 8-11, 14, 20-23 Corythosaurus 18 Indricotherium 24-25 mould fossil 28 Pleistocene epoch scute 19 WY anapsid reptiles 10 flying reptiles 20-21 Cretaceous period interglacial 7, 24 7, 24-25 Scutosaurus 11 warm-blooded animals24-25 Andrewsarchus 24-25 fossil footprint 28 7, 12-15, 17, 18-23 iridium 12 plesiosaur 22-23 sediments 28-29 ankylosaurs 18 Wiwaxia 9 cyanobacteria 8 fossils 28-29 plesiosauroids 23 sedimentary rock 29 Ankylosaurus 18-19 Yangchuanosaurus 17 N Plesiosaurus 23 Seismosaurus 17 Anomalocaris 8 Neanderthals 27 Pliocene epoch 7 Shonisaurus 17, 22 anthracosaurs 10-11 nothosaurs 22 pliosaurs 22-23 Silurian period 7, 9 Anurognathus 20 JK D Nothosaurus 22 Precambrian 6-9 skeleton 28-29 Apatosaurus 16-17 G Jurassic period 7, 12-24 30 Daspletosaurus 15 primates 27 Spinosaurus 14-15 31 apes 26 Gallimimus 15 Keratopeton 11 Deinonychus 14 prosauropods 17 Stegosaurus 19 Arandaspis 8 gastrolith 17 Komodo dragon 13 Deinotherium 24 Proterozoic eon 6-7 stratigraphy 29 Archaean eon 6-7 geological time 6 Kronosaurus 22-23 Devonian period 7, 8-9, 11 O Protoceratops 14, 18-19 Struthiomimus 15 Archaeopteryx 14-15 Gigantopithecus 24 K-T extinction 7, 12-13 diapsid reptiles 10 Old World monkeys 26 Pteranodon 21 Styracosaurus 19 archosaurs 7, 10 gizzard stone 17 Diatryma 24 Oligocene epoch 7, 25 Pteranodon sternbergi 21 synapsid reptiles 11 Argentinosaurus 17 Glyptodon 24 Dilophosaurus 14 Opabinia 9 pterodactyls 20-21 asteroid 12-13 Gondwanaland 12 Dimetrodon 11 Ophiderpeton 11 Pterodactylus 21 Australopithecus 26 great apes 26 L Dimorphodon 20-21 orangutan 26 pteroid bone 21 labyrinthodonts 11 dinosaurs 6-7, 10, 12-19 Ordovician period 7, 8-9 pterosaurs 7, 12, 20-21 Lambeosaurus 18-19 Diplocaulus 11 ornithischians 7, 12-13, T land bridge 27 B diplodocid 17 18-19 Tapejara 20-21 Lariosaurus 22 bacteria 7-8 Diplodocus 16-17 H Ornithocheirus 20-21 tectonic plates 6 Laurasia 13 Baryonyx 14 DNA 28 Hadean eon 7 ornithomimids 15 Teleopsaurus 23 lepospondyls 11 Q bipedal 12-13 Dsungaripterus 20-21 hadrosaur 7, 18-19 Ornithomimus 15 Telicomys 24 Liopleurodon 22-23 quadrupedal 12-13 bird 14-15, 24-25 duck-billed dinosaurs 18 Hallucigenia 9 ornithopods 19 Temnodontosaurus 23 lobefins 7, 8-9 Quaternary period 6-7, 25 Brachiosaurus 16-17 Dunkleosteus 8-9 Hedonus 23 Out-of-Africa theory 27 temnospondyls 11 Lystrosaurus 6 Quetzalcoatlus 20-21 Brontosaurus 16 herbivores 12 Oviraptor 15 Tenontosaurus 14 Burgess Shale 8 Holocene epoch 7, 24-25 Tertiary period 6-7, 12, 25 hominids 26-27 tetanurans 15 hominoids 26 tetrapods 9 E Homo erectus 26 M P R therapsids 11 C Edaphosaurus 11 Homo ergaster 26-27 Mamenchisaurus 17 Pachycephalosaurus radioactive decay 28 Therizinosaurus 15 Camarasaurus 16 Ediacaran fauna 8 Homo habilis 26 mammals 7, 11, 13, 24-25, 27 18-19 radiocarbon dating 28 theropods 7, 12-15 Cambrian period 6-7, 8-10 Elasmosaurus 22-23 Homo heidelbergensis 27 mammoth 25 Palaeocene epoch raptors 15 titanosaurs 17 carbon 28 Eocene epoch 7, 24-25 Homo neanderthalis 27 woolly 25 7, 25 relative dating 29 trace fossil 28-29