Stegosaurus

Stegosaurus is the largest member of the stegosaur family - a wide-ranging group of large plant-eating dinosaurs found around the world. The most impressive features of Stegosaurus are undoubtedly the two rows of plates running down its back. When these were first spotted, palaeontologists presumed they were for defence we now know this isn't the case. Firstly, the plates are too weak to hold off another dinosaur. Secondly, they don't really protect the most vulnerable parts of the dinosaur,...

Close family

Most palaeontologists believe that the large meat-eating dinosaurs live and hunt alone. However, Albertosaurus might be the exception to the rule. The remains of nine Albertosaurus have been found together. What's more, the dinosaurs appear to be of different ages. Does Albertosaurus believe that the family that hunts together stays together This means that the other tyrannosaurs might also live in family groups, but we just haven't seen any evidence of this yet. ere found North A Height 3.4...

Forerunner

Although Massospondylus is the forerunner of huge sauropods such Brachiosaurus, there are differences. Size is the most obvious, plus the ability of Massospondylus to walk on two legs. This two-leggedness may be linked to the fact the dinosaur can grip things with its front feet and has a large thumb claw on each foot, probably used in self-defence.

Early giant

Euskelosaurus is one of the biggest dinosaurs you'll see in the Triassic period. Part of the prosauropod group, these four- legged beasts are forerunners of the huge sauropods of the Jurassic period. You'll have to be quick off the mark to get a good look at one of these dinosaurs. Some palaeontologists believe that Gallimimus is the fastest dinosaur of its day.

Dentists delight

Although Troodon's prey might disagree, the thing which palaeontologists find particularly exciting about Troodon are its teeth. Almost triangular in shape, they have spiky edges on both sides, making them incredibly sharp. Troodon also has a large number of them - some palaeontologists estimate that it has over 100 teeth - so, if anything ends up in its mouth, you can be fairly sure it's going to stay there. Family Troodont.dae Period Late Cretaceous Where found USA Height 1 metre (33 ee...

Broody

This is what you will see if you happen to spot an Oviraptor nest site today. Because a female Oviraptor does not cover her nest in vegetation like some dinosaurs, she must keep her eggs warm by sitting on them - just as birds do. The nests are hollowed out of the ground and can contain up to 22 eggs. Family Oviraptondae Period Late Cretaceous Where found Mongolia Height 1 metre (3.3 feet)

Herrerasaurus

This South American predator is one of the earliest true dinosaurs, roaming the earth nearly 230 million years ago. Herrerasaurus is a meat eater, as its sharp teeth clearly indicate, and it uses its speed to ambush prey. It also has long, sharp, grasping claws that are ideal for catching and tearing up meat. Herrerasaurus feasts on plant-eating dinosaurs and even on smaller meat-eaters, too.

Missing link

Archaeopteryx was the first feathered dinosaur to be found anywhere. Originally, palaeontologists suggested it could be a major link between dinosaurs and birds, but now some think that Archaeopteryx is a bit of a dead end in avian evolution. It has feathers and light bones like birds do, but it also has a flat breastbone and a long, bony tail, which birds don't have. However, Archaeopteryx is some kind of link between feathered and non-feathered creatures and, as such, is a highly prized...

Trachodon

If Trachodon is not quite an obsolete name, it is certainly of a dubious nature. When dinosaur hunter Joseph Leidy found a couple of teeth in the 1850s, he thought they were from a completely new species of dinosaur - one that he named Trachodon, which means 'rough tooth'. However, in time, there were mutterings that all might not be well with Trachodon. The discovery of Hadrosaurus was enough to convince some people that the two species were in fact one and the same. Other discoveries...

Ceratosaurus

The Jurassic world is certainly a dangerous place to be. Another relative of that dangerous Allosaurus family is the Ceratosaurus - a big, sharp-toothed meat-eater that it is wise to stay well clear of. Ceratosaurus is a typical predator of the Jurassic period. It's big, walks on two powerful legs and has two smaller yet comparatively strong arms with four fingers on each. As a relative of Allosaurus, it may even hunt in packs, an idea that might recently have been proved by the discovery of a...

Long neck and tail

The most obvious feature of Diplodocus is its extremely long neck and tail. Its neck is about 8 metres (26 feet) long, but at the end of it is a tiny head measuring less than 1 metre (3.3 feet). The tail is just as impressive as the neck and makes an effective whip-like weapon for repelling predators. How to say it d'-PLO-do-KUS Meaning of name Double beam Family Diplodocidae Period Late Jurassic Where found USA Not all long-necked dinosaurs eat leaves from the treetops, and Diplodocus is a...

Hunter or hunted

Of course, Herrerasaurus won't just eat other dinosaurs. The dinosaurs do not have the planet to themselves other reptiles and insects lived here at the same time. So, although this gives Herrerasaurus a wide-ranging menu, it also means that larger predators might also have put dinosaurs down as a tasty snack for themselves. Penod Early Triassic *9ht 1 metre (3

Styracosaurus

Despite its fearsome appearance, Styracosaurus is a peaceful dinosaur, like all members of the ceratopsid family. It lives in small herds and eats plants, migrating slowly across the continent in search of food. Those spiky horns on the edge of the head of Styracosaurus might look dangerous, but many palaeontologists believe they are just for show. The pointy frill makes the dinosaur appear even Period grte and Montana, USA Length 5 metres 06.5 feet) Weight 1,450 kilograms 0-6 tons) bigger and...

Hanging around

Of course, much of a palaeontologist's work is open to debate and contradiction. Many scientists are not convinced that Abelisaurus is a separate sort of dinosaur at all, but suspect it is actually Carcharodontosaurus (car-CHA-row-DON-toe-SORE-us), the big Moroccan predator. If so, it would mean Carcharodontosaurus was in existence not only later, but also in a different area. This Cretaceous dinosaur is a classic predator it has a big head filled with sharp teeth, powerful legs and a big,...

Discovery

Dinosaurs have been discovered on every continent on earth, although some areas have a larger concentration of finds than others. This may indicate either the amount of time spent excavating the fossil beds (areas with a high concentration of fossils) or the number of dinosaurs that lived in a particular area.

Massive muncher

Quaesitosaurus, like all the large sauropods, has to consume a huge amount of food every day just to keep going. For a big dinosaur, it has only got a little mouth, so those jaws work hard every day, especially seeing as leaves are not always the most nutritious of foods. These dinosaurs spend most of their time eating. Many plant-eating dinosaurs - Quaesitosaurus included - carry gastroliths in their stomachs. These are stones that the dinosaur swallows to help grind up the food inside its...

Thagomizer

Like its more famous cousin, Stegosaurus, Wuerhosaurus has a fearsome weapon at the end of its tail. These four sharp spikes are quite effective at warding off all but the biggest or most persistent of predators. The name palaeontologists use for the stegosaurid club is 'thagomizer', which comes from a Gary Larson cartoon showing a caveman telling others that the pointy end of a Stegosaurus was named after the late Thag Simmons, who was apparently killed by a thagomizer.

Abelisaurus

Named after Roberto Abel of the Argentinian Museum of Natural Sciences, this late Cretaceous dinosaur is something of a mystery but we do know it's a pretty fearsome predator. -to RFEL-ee-SORE-us H0W10 l ame Abel's lizard Period Late Cretaceous Where found Argentina -to RFEL-ee-SORE-us H0W10 l ame Abel's lizard Period Late Cretaceous Where found Argentina Length 9 metres (29.7 ft*U Weight 1,300 kilograms 0-4

Whats in a name

Ornitholestes means 'bird eater', and it was given this name because palaeontologists believed it could eat early birdlike dinosaurs like Archaeopteryx. There is one problem with this theory, however - no one has spotted any of these birdlike dinosaurs in the territory of Ornitholestes. Either it has eaten them all already - which is unlikely - or they just can't be found here, so the name is misleading.

Zephyrosaurus

Not many dinosaurs begin with the letter Z, so Zephyrosaurus is something of a collector's item. Keep your eyes peeled for this one if you're spotting in the United States. Early Cretaceous Where found USA Height 1 metre (3 feet) Length 2 metres (6 fee ) We ght Not known F od Plants Special features Agile r in. m sn k Jin iinr ii ji r in. m sn k Jin iinr ii ji Since Zephyrosaurus is a small and agile dinosaur it is really skilled at zipping around. When you have no armour plating or defensive...

Ankylosaurus

Ankylosaurus Defence Pictures

This is the last and possibly the most famous of the ankylosaurids. Ankylosaurus is big, wide, heavy and covered in bony plates. This is one well protected dinosaur, and most predators have to think twice before trying to tackle it. The body of Ankylosaurus is all about defence, being covered in thick plates of bone fused into the dinosaur's skin. This forms a hard, shell-like structure over the creature it even has bony plates over its eyes. Not only that, but its body is covered in rows of...

Dinosaur

Carbonaceus Reptile

Dinosaurs are a large yet very specific group of creatures. To qualify, an animal has to satisfy a number of criteria 0 It must have lived during the Mesozoic era see page 10 . 0 It must be a reptile, although not all reptiles are dinosaurs. For example, lizards are reptiles, but they are not dinosaurs. 0 Its legs must be located below its body, giving it an erect stance, as opposed to sticking out from the sides, like those of a crocodile. 0 It must have lived on land, not in the air like...

Much like Diplodocus

Diplodocus Apollo

Mamenchisaurus looks a lot like Diplodocus, especially with its long, downward-pointing neck and whippy tail. It is only when you get really close that the differences become apparent, namely the head and teeth. However, we would recommend that you take our word for it and don't venture too H0Wt S LmeMamenchiliZard Meaning of name iv Family Euhelopodidae Period Late Cretaceous

Giganotosaurus

Dinosaurs Carnivores

When Giganotosaurus was first spotted in Argentina, it started a big debate - is this dinosaur the biggest meat-eater ever Many palaeontologists believe that Giganotosaurus is the largest of all the dinosaur carnivores - even larger than Tyrannosaurus rex. From sightings made so far, it certainly seems to be longer and taller than its more famous rival. However, like Carcharodontosaurus, it also seems to be more lightly built than Tyrannosaurus rex, so the argument continues about who is the...

Saurolophus

Duck-billed dinosaurs such as Saurolophus are very common, but if you want to see how dinosaurs operate as a herd, then watching the various members of the hadrosaur family is a rewarding experience. As with other hadrosaurs, the crest of Saurolophus is used as a communication device. In this instance, tubes from within the crest link up to a balloon-like pouch on the creature's snout. Because Saurolophus travel in herds, they can be noisy company to keep. How to say t SORE-OL-o-fus Meaning of...