Dinosaur Walk Museum modern day birds. Troodon: The Troodon, a very small bird-like dinosaur, grew to be up to in length, tall and only weighed up to 130 pounds. Living during the late Cretaceous Period, 75–66 million years ago. Originally thought to be carnivorous, modern evidence shows that it is possible that they were omnivorous or possibly an herbivore. Plesiosaurs: The Plesiosaurs were carnivorous aquatic reptiles. First appearing at the beginning of the Jurassic Period they thrived throughout the Cretaceous Period. They lived during the same time as the dinosaurs but were not dinosaurs, they are considered reptiles. Oviraptor: The Oviraptor, or "Egg
Dinosaur tooth data that has been collected through dinosaur dental histological studies are typically unavailable through other means and has provided us with a more in-depth understanding on their biology. One of the most significant findings is that despite differences in their appearance, dinosaur teeth are essentially composed of the same dental tissues found in modern mammals, crocodilians and other amniotes, suggesting that these tissues first evolved in a common ancestor and has been retained ever since. Another finding is that the lines of von Ebner can be counted similar to tree rings to determine the age of a tooth. Furthermore, as