In this lesson, we will look at some examples of theropods, which were the bipedal, carnivorous dinosaurs such as the Tyrannosaurus rex from which birds have descended.
The most terrifying dinosaurs to walk the earth were theropods.
Theropods (meaning ‘beast-footed’) are of the order of saurischian (‘lizard-hipped’) dinosaurs. They were carnivorous, bipedal dinosaurs that had hands with five fingers that could grasp things. While dinosaurs are extinct, their descendants are birds that still exist today. In addition to their sharp teeth and claws, these dinosaurs are known for having hollow bones. Let’s look at some examples of theropods.
The Herrerasaurus (‘Herrera’s lizard’) was one of the first known theropods. Similar to other theropods, it was bipedal, had long claws extending from its fingers, and had long, sharp, serrated teeth.
Furthermore, its hinged jaws could effectively hold its prey. Its lower arm and wrist bones are similar to those of birds. While you might not want to run into one of these creatures, they were not the most dangerous predator of their time. Standing four feet tall and weighing about 460 pounds, these dinosaurs had much larger carnivores to deal with. Herrerasaurus lived in the Triassic period, which was about 230 million years ago.
Fossils of this dinosaur have been found in Argentina in South America.
Ceratosaurus (‘horned lizard’) was a large carnivore from the Jurassic Period, which was about 150 million years ago. This dinosaur was 15-20 feet long and weighed about a ton. One of its most prominent features was a horn on its snout and ridges above its large eyes. This theropod only had four clawed fingers per hand.
Ceratosaurus were highly intelligent dinosaurs who worked in groups to outwit their prey, which was likely iguanodonts, stegosaurs, and sauropods. In addition to being a hunter, it may also have been a scavenger. This dinosaur was bipedal and may have been a good swimmer as well because of its long tail.
Tetanurae are theropods that have large hands, an inflexible tail, and only have three or four fingers. There are two subgroups of tetanurae: carnosauria and coelurosauria.
Carnosauria (‘meat-eating lizards’) were some of the most dominant dinosaurs of the Jurassic period. Having evolved from earlier theropods, these much larger dinosaurs had a more pronounced femur, large eyes, and a narrow skull.
Allosaurus is the best-known carnosaur. Their talons, claws, strong jaws, and sharp teeth made them effective hunters.
Coelurosauria are most closely related to modern birds. They are known for their long arms and hinged ankles.
There is still much to learn about this group of animals, which often involves reclassification. There are three categories of coelurosauria:
- Maniraptora, which includes velociraptors.
- Ornithomimidae, which includes bird-like coelurosauria.
- Tyrannosauridae, which includes the largest coelurosauria, such as the Tyrannosaurus rex.
Theropods come from the order of saurischian dinosaurs. These are bipedal carnivores with grasping fingers, sharp teeth, and clawed hands and feet. While dinosaurs are extinct, their descendants, birds, share their hollow bones.
The oldest theropod is Herrerasaurus, who lived in Argentina during the Triassic period. These dinosaurs weighed less than 500 pounds. Next, came the Ceratosaurus during the Jurassic period. The Ceratosaurus weighed about a ton. Tetanurae are divided into two groups: Carnosauria and Coelurosauria. Allosaurus is a Carnosauria. Tyrannosaurus rex and Velociraptor are Coelurosauria.
Coelurosauria have most in common with birds.