In his new book for curious dinosaur detectives, Sean Callery explains 30 amazing dino topics in just half a minute, keeping young archaeological adventurers on their feet!
The ‘Age of the Dinosaurs’ lasted 160 million years – 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…
About 225 million years ago (MYA) small dinosaurs took their first steps on Earth. There weren’t 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 aren’t certain but have some good ideas. They know three types –theropods, sauropodomorphs and ornithischians –were 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 ‘lizard-hipped’. Their pelvis points downwards and towards the front, as in lizards. Ornithischians are ‘bird-hipped’ – two 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 –some 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 Jurassic’s 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 –66 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 –which is how much food it needed to survive.
(Text with image of Gigantosaurus)
Lable it – 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.
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 wouldn’t have been as clever as your pet cat.
Dinosaurs roamed the planet for 160 million years but dies 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 didn’t 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 ‘megatsunamis’. Dust would have blocked out the sun for months –plants 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.
Despite their name meaning ‘terrible lizard’ dinosaurs are not lizards, partly because of how their legs joined to their bodies. Lizards sprawl with legs spread out. Dinosaur legs came straight down from their bodies, to hold a heavier weight and move faster for longer.
Activity: 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.
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 – 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.
Dinosaurs in 30 Seconds by Sean Callery with illustrations by Sam Hubbard is published by Ivy Kids. Recommended for ages 8+ RRP £7.99