14
THEROPODS
Roaming the Mesozoic terrorising weaker organisms, Theropods were and still are a very diverse group of mostly carnivorous bipedal dinosaurs that range in size from tiny birds to the Spinosaurus, the largest land carnivore of all time. Theropods are the only group of dinosaurs that survived the K/T extinction via the group Aves that eventually went on to become today’s birds.
Theropods are the center of a very problematic topic: scales or feathers?
At the moment, we know that the group began shifting apart and dividing into different groups with very different characteristics: the group that included the famous with a crest on their heads like Dilophosaurus, the group of very tiny arms that included Carnotaurus, the group of the massive Jurassic Park 3 star Spinosaurus and its relatives, to the groups that are closer to birds like the relatives of the Allosaurus. At that point, all groups still had scales and no feathers were obs
ervable on fossils.
Fossil records then show a very interesting Theropod that is thought to be the first feathered dinosaur: Sciurumimus
a tiny Late Jurassic dinosaur the size of squirrel that is believed to have had small protofeathers on its back. As evolution went on, a new branch appeared in the Early Cretaceous that included all Tyrannosaurus. Tyrannosaurs are believed to have had protofeathers on their backs and the group contains the third biggest land carnivore of all time: the notorious T-Rex as well as its other terrifying cousins like Tarbosaurus, Yutyrannus and Albertosaurus all living in different areas, different conditions and at different times.
Feathered dinosaurs would continue to appear in different groups through dinosaurs that resemble Ostriches to the group were true feathers were developing and the closest relatives of the birds: Maniraptora.
The node of Maniraptora has been unique for the way their wrists flex downwards and for their real complex feathers, and this is where feathers as we know them appeared. The node sees unique and famous members like the:
Oviraptorians who were found fossilised around egg nests which shows a very interesting bird-like
behaviour when it
comes to caring for its
hatchlings, but the most
interesting feature of the
Oviraptors is that it didn’t have
teeth to make it a herbivore
or a carnivore or even an ovivore
but mostly a dinosaur that fed on mollusks. Therizinosaurians
found in the late Cretaceous
with a very bizarre appearance
looking like big birds with
3 long sharp claws on each hand.
They were a very interesting
group of dinosaurs as they
were herbivores but were no easy prey for Carnivores as they were able to do serious damage to even the mightiest carnivores.
Sciurumimus, an extinct Theropod and one of the first feathered dinosaurs