HORNS, SPIKES, & ARMOR Beaks, frills, and crests Fierce dinosaurs Plant-eating dinosaurs were The fragile plates along the back may have Many plant-eating dinosaurs All those spikes and armored often slow-moving, trudging changed color to attract a mate or warn a rival. had beaks, rather like the beak TRICERATOPS plates gave protection against Or Stegosaurus might have used them to control Frenchman Formation 3 (try-SER-ah-tops) along on all fours. It would be its temperature, turning towards the wind to of a tortoise. They used their terrifying carnivorous dinosaurs. cool down or standing in the sun TRICERATOPS LIVED: Canada, US; hard for them to run away from to warm up. beaks for shearing through 68–66 mya ATE: Plants These predators came in all sizes, a fierce meat-eater, so some plant matter or for gripping Triceratops had three LENGTH: 26 ft. (8 m) but shared good eyesight, speed, horns and a distinctive neck WEIGHT: 24,200 lb. grew armor plates and sharp, and tugging at it. Beaked frill. Channels for blood vessels (11,000 kg) fearsome teeth, slashing claws – protective spikes. dinosaurs often had dramatic on the frill suggest it could be and often feathers! frills or crests on their heads. flooded with blood to change color, either to attract a mate STEGOSAURUS Morisson Formation 8 Albertosaurus’s 3.3 ft. Morrison Formation 7 (STEG-oh-SAW-rus) or scare a rival or predator. (1 m ) long skull was packed with sharp, 1 Horseshoe LIVED: US, Portugal; Lance Formation 10 ALLOSAURUS saw-edged teeth. STEGOSAURUS 156–144 mya Canyon Formation Allosaurus was one of the Stegosaurus had a fearsome ATE: Plants LENGTH: PACHYCEPHALOSAURUS 2 Dinosaur Provincial Park ALLOSAURUS weapon called a “thagomizer” at the end 21 ft. (6.5 m) WEIGHT: 9 Cedar Mountain first dinosaurs investigated ALBERTOSAURUS Pachycephalosaurus was a (AL-oh-SAW-rus) of its tail, with long, sharp spikes sticking 7,700 lb. (3,500 kg) Formation PARASAUROLOPHUS using computer modeling. Albertosaurus was smaller than bonehead – literally. Adult It made swift bites, slashing LIVED: US; 150 mya Tyrannosaurus but just as fast and out on each side. It could use this to swipe an The bony crest of Parasaurolophus hides a network ATE: Meat LENGTH: ALBERTOSAURUS GASTONIA skulls were topped with a PACHYCEPHALOSAURUS and tearing at its prey with deadly. Young Albertosaurus grew attacking dinosaur. One Allosaurus fossil shows of airways. It may have used its crest to make 28 ft. (8.5 m) WEIGHT: (al-BERT-oh-SAW-rus) Gastonia had spikes dome of bone up to 10 in. (pak-ee-SEF-ah-loh- sharp, backwards-curving quickly, and were the largest predators an injury to the tail probably caused by SAW-rus) sounds, passing air from its throat through 3,300 lb. (1,500 kg) LIVED: Canada; 76–74 mya and armored plates (25 cm) thick. The dinosaur teeth. It could easily kill small ATE: Meat LENGTH: in their area by the age of just two. a bashing from a Stegosaurus. LIVED: US; 70–66 mya Different species of the crest rather like a trumpet. to keep it super-safe. Any predator may have used its hard Parasaurolophus have animals, and might even have attacked heavier 29.5 ft. (9 m) WEIGHT: They might have hunted in packs – that ATE: Plants LENGTH: Scientists have used computer 4 Hell Creek Ankylosaurus was entirely covered in trying to get close ran the risk of head for butting the flanks different types of crests. They animals like Stegosaurus by relying on speed. 2,900–3,700 lb. (1,300–1,700 kg) would have been a fearsome sight! 4.8 ft. (4.5 m) WEIGHT: models of the crest to try to hard, bony plates called osteoderms. receiving a nasty injury from of rivals when fighting for would have looked different, ANKYLOSAURUS 90 lb. (450 kg) and probably made different re-create the sound of a Four spikes at the back of the Gastonia as it swiped its spiked tail. territory or a mate. sounds, helping potential Parasaurolophus call. Antlers Formation 11 head protected the neck, mates to find the right species. and even its eyelids were DEINONYCHUS armored. The large club of Deinonychus had giant, curved claws on its fused bone at the end of the feet to hold its prey still. The largest claw tail could deliver a could rotate, so Deinonychus could nasty thump. ANKYLOSAURUS GASTONIA The bone was hold it out of the way while walking. (an-KILE-oh-SAW-rus) (gas-TOE-nee-ah) not solid but filled Gastonia had short legs This bird-like dinosaur was found in 1964. with holes, like a sponge and couldn’t outrun its DEINONYCHUS LIVED: Canada, US; 74–67 mya LIVED: US; 142–126 mya – solid bone would have Work on it by the American paleontologist attackers. It relied on its (die-NON-ee-kus) ATE: Low-growing plants ATE: Plants been very heavy. Babies John Ostrum sparked a revival of interest in LENGTH: 23 ft. (7 m) thick armor for defense. LENGTH: 16 ft. (5 m) PARASAUROLOPHUS LIVED: US; 120–110 mya may have had a flat head, LENGTH: 24.5 ft. This computer model of an Allosaurus skull was used to the study of dinosaurs in the 1970s, which WEIGHT: 13, 200 lb. (6,000 kg) WEIGHT: 4,200 lb. (1,900 kg) growing bony domes as (PAR-ah-SAW-oh-LOH-fus) ATE: Meat (7.5 m) WEIGHT: study how the dinosaur used its teeth to tackle its prey. became known as the “Dinosaur Renaissance.” Ankylosaurus’s skull was protected by bony scales. they matured. LIVED: Canada, US; 76–74 mya LENGTH: 10.8 ft. (3.3 m) ATE: Plants 5,700 lb. (2,600 kg) WEIGHT: 130 lb. (60 kg) NORTH AMERICA Tyrannosaurus rex is the The enormous head FOSSILIZED FIGHT had a narrow snout, dinosaur everyone has heard of making the eyes close DINOSAUR HUNT The fossil on the right was found in 2006 together. This meant FOSSIL- Once they’ve found some suitable rocks, paleontologists look – it’s the most famous dinosaur Tyrannosaurus had good Hell Creek and shows two dinosaurs tangled up binocular vision, just for clues that might reveal dinosaur remains. They may find 4 of all, and one of the largest together. The one on the left is like we do. HUNTING fragments of bone in riverbeds, fossilized footprints, or bits meat-eaters that has ever lived. probably a young Tyrannosaurus of bone sticking out of the rock. Desert areas are often T-REX and the other a large ceratopsian. Dinosaurs lived 242–66 million the best places to look, as fossils are exposed by Some paleontologists think they may years ago, so to find their fossils scouring winds but not washed away. TYRANNOSAURUS REX have battled to the death. So did the (tie-RAN-oh-SAW ACTUAL SIZE TOOTH! paleontologists need to look ceratopsian fall victim to the 1 -rus REX) Tyrannosaurus? There is a tooth in rocks of that age. In North LIVED: US; 68–66 mya The dinosaur wedged in its neck. America, rocks the right age ATE: Meat LENGTH: needed a heavy 39 ft. (12 m) WEIGHT: tail to balance are near the surface in a band 13,200 lb. (6,000 kg) its enormous head so that it running through the middle of didn’t tip over. It’s odd to think of the continent. In the northeast something so fierce The largest T-rex tooth ever covered in feathers – but and midwest, the rocks are too Tyrannosaurus probably old for dinosaur fossils, while in had at least some the root that held it in the jaw. feathers. The babies may found was 12 in. (30.5 cm) long, including the southeast, they are too new. have been covered in down, like bird chicks! Sweet, but savage… 2 BARNUM BROWN Tyrannosaurus would have The first Tyrannosaurus fossil was held its tail out horizontally DIGGING AWAY The powerful jaw and behind it as it walked. found in 1902 in Hell Creek by the Fossilized Tyrannosaurus teeth of T-rex could rip When they find a large skeleton, fossil-hunters American fossil-hunter Barnum The teeny, poop contains bits of large chunks out of other first remove large chunks of surrounding Brown (1873–1963). tiny arms were bone and muscle from dinosaurs. The front teeth rock, called overburden. Then they carefully too short to its meals. Tyrannosaurus curved backwards, so probably hunted other scrape and brush away the remaining rock Brown uncovers dinosaur bones in Wyoming reach the mouth. they wouldn’t be pulled dinosaurs and ate any during a dig in the 1930s. No one knows how out when Tyrannosaurus and soil to reveal the bones. It can take weeks. Tyrannosaurus used dead animals it found tore at flesh. They photograph the positions of all the bones lying around. Tyrannosaurus had them – perhaps to hold FIRST AMERICAN before moving them. the longest legs for its smaller animals while size of any dinosaur. biting them. BATTLING TEENS They were powerful DINOSAURS enough to let it run at Bite marks on the skull of a young around 19 mph (30 kph). Tyrannosaurus found in 2001 are from When the first dinosaur footprints were found This American Hadrosaurus was the first dinosaur NORTH AMERICA NORTH the teeth of another young – probably in North America in 1802, people thought they skeleton to be reassembled and mounted for teenage – Tyrannosaurus. The bite healed, were the footprints of giant birds. Only after display anywhere in the world. The paleontologist so perhaps it wasn’t a very serious fight.