#abelisaurs

So, the muscles in the neck area, as a rule, get really buff when theropods become large predators - it happened in Abelisaurs, it happened in Allosauroids, it happened in Megalosaurs, it happened in Tyrannosaurs. This is because, as the animal gets bigger, it tends to interact with prey and the environment more with its mouth and jaws than with its arms, because the mouth and jaws are more powerful and efficient. The musculature in the neck region directly conflicts with musculature in the upper arm for space, as they are next to each other. As such, as the muscles in the neck grow, the muscles in the arm shrink. This leads to a corresponding shrink of the arms in these large predators. In each line, if they had continued to evolve, they may have lost their arms a la Moas.

Abelisaurs, however, kept their tiny arms, and what's weird, is that the arm is attached to a completely 360 degree rotational socket, unlike the sockets the rest of us have at the arm. As such, they were able to wiggle and move them a LOT. This leads researchers to think that they were used, specifically, for display.

Remember everyone: every single dinosaur, every single one, is a variation of the peafowl.

Dinovember Day 20: Carnotaurus

The "Meat Eating Bull", the most iconic Representative of #abelisauridae.

Hi there!

Known from several well-preserved skulls, Majungasaurus can be distinguished from other abelisaurids by its wide skull, its thick, roughly textured bone on its snout, and the single rounded horn on the top of its skull, which was originally mistaken for the dome of a pachycephalosaur. It also had more teeth than moth other abelisaurids.