Name means: Meat Bull
Range: Late Cretaceous (Santonian-Maastrichtian, 85-70 MYA) from Argentina
Size estimate: 25-30 ft length, 1-1.5 tons
Discovery: Jose Bonaparte, 1985
Classification: dinosauria, saurschia, theropoda, ceratosauria, abelisauridae
Dinosaurs don’t often get weirder than Carnotaurus. Scientists have recovered only one skeleton of this species, but it preserved so much information that we know more about it than many other dinosaurs. This skeleton only lacked the shins, feet, and end of the tail. It even preserved large portions of scaly skin impressions. Such a well-preserved find gives us an excellent look at its unusual features.
Unlike the crests found on other theropods, Carnotaurus’ horns grew thick enough to have a function beyond looks. Their unusual D-shaped cross-section hints at a specific use, but figuring what they did with these horns may take years of study. We may never know.
Scientists disagree about the capabilities of Carnotaurus’ short jaws. Some studies find that they lacked strength and might have focused on catching small prey. Others find that they had stronger bite forces than the average theropod. Furthermore, animals that probably hunted sauropods, like Allosaurus, trended toward shorter snouts over time. Some scientists consider that a sign that Carnotaurus hunted sauropods as well.
Examining the other end of the animal doesn’t clear up the argument over jaw function, either. Carnotaurus had unusual backbones at the base of its tail. Most dinosaurs had t-shaped fins attached to the top of the round part of the backbone. In Carnotaurus, these fins had a shape more like a fork, with the bars of the t-shape angled upwards. The angles of these fins made more room for gigantic muscles that pulled the leg back. This made Carnotaurus fast for its size, but also less agile on turns. Does this mean it chased quick little animals or launched surprise attacks on giant dinosaurs? We don’t yet know. Whatever Carnotaurus’ lifestyle, it seems to have developed to do a few specific things really well.