Dinosaurs in 30 seconds
In his new book for curious dinosaur detectives, Sean Callery explains 30 amazing topics in just half a minute with fast-track facts presented in energetic bite-sized morsels, keeping young archaeological adventurers on their feet!
The ‘Age of the Dinosaurs’ lasted 160 million years ñ about 800 times longer than humans have been around. But how do we know all this existed? Palaeontologists of course, who dig out the truth of how these great beasts lived so long ago. Yet many dinosaur mysteries remain. What was their skin colour? What did they sound like? We know they died out quickly, but there are still questions about how and why. Get your tools ready as we dig deeper…
Dinosaurs Arrive About 225 million years ago (MYA) small dinosaurs took their first steps on Earth. There werenít many of them and they looked nothing like the enormous beasts we think of today. Some became plant-eaters; others hunted and ate meat. Some walked on four legs; others on two. But what was the first dinosaur? Scientists arenít certain but have some good ideas. They know three types ñtheropods, sauropodomorphs and ornithischians ñwere the first to emerge in a world dominated by other much bigger reptiles like Ichythyosaurs, marine reptiles that looked a lot like fish and dolphins. It took millions of years before dinosaurs would become the most plentiful and widespread animals but by the end of the Triassic Period (201 MYA) they had become the largest and most dominant animals on land.
To better understand the thousands of different types of dinosaurs, scientists have placed them into various groups within the overall dinosaur family. Saurischians are ëlizard-hippedí. Their pelvis points downwards and towards the front, as in lizards. Ornithischians are ëbird-hippedí ñtwo of their three hipbones point backwards and are close together, as in birds. Horned dinosaurs such as Triceratops and the armoured Stegosaurus and Ankylosaurus are ornithischians. This group had beaks and only ate plants ñsome walked on two legs, some on four.
At the start of the Jurassic Period (201 MYA), the planet became warmer and wetter, with shallow seas and thriving plant life. Long-necked, long-tailed sauropods walked on four sturdy legs and were some of the Jurassicís most abundant dinosaurs. Fully grown, they were about ten times bigger than the largest carnivores at the time. In North America, Brachiosaurus and Diplodocus were particularly successful. They would have moved slowly and stayed in groups for protection, possibly even mixing together.
The Cretaceous Period (145 ñ66 MYA) included ferocious meat-eaters such as Velociraptor and Tyrannosaurus rex as well as plant-eating duck-billed and crested dinosaurs that raised their young and lived in groups. T. rex was big, but Giganotosaurus, a carcharodontosaur, was about 2 m (6.5 ft) longer and roamed Earth 30 million years earlier. It had longer arms and weighed 7-13 tonnes ñwhich is how much food it needed to survive.
What was the most terrifying dinosaur to ever walk the Earth? Most would say a T. rex, but to a dinosaur in Cretaceous times, it was probably a dromaeosaur, sometimes known as a raptor. Dromaeosaurs had a big brain for their size, and were some of the smartest dinosaurs. Despite this, they still wouldnít have been as clever as your pet cat.
Gigantosaurus Its brain weighed the same as a banana – half the weight of a T. rex. It could not run as fast as a T. rex but was heavier and had longer arms.
3-minute mission – What big teeth you have… Dinosaur teeth tell us what they ate: sharp for meat, blunt for plants. Use a mirror to look at the types of teeth in your mouth: incisors; canine teeth; and molars. Bite into a carrot with different parts of your mouth and investigate what each type of tooth does best. Incisors cut well, canines hold and rip, molars grind and mash.
Dinosaur Extinction Dinosaurs roamed the planet for 160 million years but died out in just a few months. How did this happen? Many scientists believe it was the combination of a gigantic asteroid hitting Earth and a series of massive volcanic eruptions that choked the planet. Of course the asteroid didnít help. Ten kilometres wide when it smashed into Mexico, it was like thousands of nuclear bombs going off at once, blasting millions of tonnes of dust, soil and rock into the air and causing hurricanes, wildfires and ëmegatsunamisí. Dust would have blocked out the sun for months ñplants died and plant-eating dinosaurs perished. The meat-eaters starved as did three-quarters of life on Earth. Some types of animals survived, underwater or living in burrows, many of which are the ancestors of modern mammals.
Dinosaurs in 30 Seconds by Sean Callery with illustrations by Sam Hubbard is published by Ivy Kids. Recommended for ages 8+ RRP £7.99 This fresh and exciting book takes young readers on a fascinating journey from the development of the first life forms on the planet to the emergence of the dinosaurs ñ and their eventual extinction. Key topics, supported by fun active ‘missions’ explore these fascinating creatures, how they evolved, what they ate, their social behaviour and how we have come to understand them from their fossilized remains.