Knowledge Organiser for Year 3 & 4 Topic: Footprints From The Past Key questions: How do we use historic items to understand the past? E.g. fossils. How have the continents changed from 250 million years ago to the modern day? How did the dinosaurs become extinct? Can you describe the differences between carnivores, herbivores and omnivores? Can you describe the differences between the terms ‘predator’ and ‘prey’? Key facts and figures Dinosaurs roamed the planet for about 165 million years, during a time in the Earth’s history called the Mesozoic Era. The Mezosoic Era comprised the Triassic, Jurassic and Cretaceous periods. To qualify for being a dinosaur you have to be, firstly, a reptile. Secondly, you have to be land-living, either walking on two or four legs. Thirdly, you have to have lived only within the Mesozoic era. At the beginning of the Triassic period, the world would have looked very different, as one half of the planet was a giant, joined-together super-continent called Pangaea. The other half was an immense ocean. By the end of the Cretaceous period, the super-continent was breaking apart, creating the outlines of continents we now know, and new shallow seas. We also now know that the continents are always in a process of very slow movement called Plate Tectonics or Continental Drift. 251 – 200 million years ago: The Triassic was marked by dry conditions with a distinct rainy season and large red deserts. It was here that the first small dinosaurs appeared. Examples of dinosaurs present: Plateosaurus, Gojirasaurus, Coelophysis and Herrerasaurus. 200 – 146 million years ago: The Jurassic was much wetter and lusher, causing a great expansion of dinosaur evolution, with increasingly bigger species of herbivorous dinosaur feeding on conifer and cycad forests. Examples of dinosaurs present: Stegosaurus, Allosaurus, Brachiosaurus and Ceratosaurus. 146 – 65 million years ago: The climate during the Cretaceous was affected by the breaking up of Pangaea, forming continents called Laurasia and Gondwana. Most of modern Europe was like the Caribbean, with shallow tropical sea and islands. New, different types of dinosaur had evolved, as well as birds and small mammals, turtles and snakes, etc. There were new types of flowering and fruiting plants Examples of dinosaurs present: Triceratops, Tyrannosaurus Rex, Centrosaurus and Ankylosaurus. About 65.5 million years ago, nearly all large vertebrates and many tropical invertebrates became extinct in what was clearly a geological, climatic and biological event with worldwide consequences. The most popular theory for this catastrophe was a very large asteroid colliding with Earth in what is now Mexico, on the Yucatan Peninsula. Did you know…? A palaeontologist is a person who studies the fossils of dinosaurs The word ‘dinosaur’ comes from the Greek words ‘deinos’ and ‘sauros’ meaning ‘terrible reptile’, a name coined by Richard Owen in 1841 There are roughly 700 known species of extinct dinosaurs Dinosaurs existed for approximately 200 million years Key vocabulary or people Mezosoic Era Pangea Triassic Period Continental drift Jurassic Period Yucatan Peninsula Cretaceous Period Richard Owen .