April 4, 2022 Scott Kraus

Carnotaurus Was a Cretaceous Period Carnivore

Carnotaurus may not have been as large nor as heavy as Tyrannosaurus Rex, but this carnivore would have made a formidable sight. From it’s bull like horns to it’s quite incredible speed on land Carnotaurus was a force to be reckoned with.

Quick Facts

What Did Carnotaurus Look Like?

Carnotaurus was a very strange-looking dinosaur whose thick, bull-like horns eventually led to its name, as “Carnotaurus” means “meat-eating bull.” A large carnivore, Carnotaurus stood about 9.8 feet tall and weighed in at about 1.6–2.9 tons. Incredibly powerful hind legs, as well as a strong, muscular tail, allowed it to reach estimated speeds of up to 31 miles per hour. It’s also conjectured that Carnotaurus had an expandable lower jaw, almost like a snake, that could accommodate larger prey. Just imagine – a 1.6–2.9 ton dinosaur hurtling toward you at high speeds with a gaping mouth full of sharp teeth… it mustn’t’ have been fun to be the target of a Carnotaurus attack.

Physical Attributes of Carnotaurus

It’s Carnotaurus’ more unusual physical attributes that set it apart from other dinosaurs of the period. As mentioned above, Carnotaurus sported two thick horns that projected from its skull where you would find eyebrows on a person. The strange thing about these horns, though, is that while they were made of bone (and thus incredibly hard), they were too small to be of much use in combat or predation. It’s thought that these horns may have possibly been used for mating purposes. The skull itself was thick and strong on top and weaker in the region of its slender, expandable jaw. Perhaps also contributing to its name, Carnotaurus had a blunt snout, comparable to a bulldog.

But perhaps the strangest thing about Carnotaurus was its arms. These small and stubby appendages were even shorter than the arms of the T-Rex, and appear to be even less functional. Extremely thin, and almost ridiculously tiny, the arms of the Carnotaurus didn’t even bend. It’s as if Carnotaurus’ strange arms ended at the elbow, with four fingers that were just slightly smaller than the forearms, one of which was a spike. Some conjecture that the animal may have eventually lost these front limbs completely as they continued to evolve.

Another interesting and distinguishing feature of the Carnotaurus was its eyes. The eyes of the Carnotaurus faced forward, rather than to the sides as most dinosaurs of the time. It’s thought that this characteristic may have given Carnotaurus binocular-like vision.

The strange appearance of this dinosaur extends all the way to its skin, where well-preserved impressions found with the fossils tell paleontologists that Carnotaurus’ body was covered in bumpy protrusions, or “tubercles.” These two-inch tubercles became more concentrated near the region of the animal’s spine, and it’s not quite certain what purpose they may have served.

What did Carnotaurus eat?

It’s likely that Carnotaurus dined upon small and medium-sized herbivores (or plant-eaters). Its delicate but expanding jaw allowed it to swallow large amounts of meat at once.

Though its horns were too short and delicate to be used as a method of predation, it’s possible that the presence of these horns as a method of mating ritual point to the likelihood that Carnotaurus lived, and possibly even hunted, in groups. Carnotaurus’ long neck allowed it to swing its head, thus stunning prey with powerful blows and somewhat weaker bites. It’s long, muscular, powerful legs allowed it to chase after its prey. What is puzzling about the Carnotaurus is the juxtaposition of its heavy, powerful upper skull with its strange, snub-nosed snout and weak, delicate jaw.

How did Carnotaurus move?

The presence of a large, muscular tail, combined with the frontal characteristics of the Carnotaurus (large head, small and frail arm structures), suggest that the tail of the animal acted as a means of balance, helping to keep the dinosaur upright while walking and running. Its muscular back legs, combined with the balancing power of its heavy tail, allowed the Carnotaurus to reach incredibly speeds of up to 31 miles per hour. Its speed, combined with the weight and strength of its horned head, would have made Carnotaurus a formidable predator.

Where did Carnotaurus live?

 Setting the Stage

During the Cretaceous period (145.5 to 65.5 million years ago), the world was very different from the way we experience it today. Pangaea, the landmass that was comprised from all of the Earth’s continents, was beginning to drift apart and the Earth itself was beginning to cool down from its tropical and sub-tropical state. By the end of the Cretaceous period, when the Earth experienced the extinction event that brought an end to the dinosaurs, Pangaea had broken into smaller continents and the Earth began to experience the meteorological beginnings of what would become the seasons we know today. The breaking up of Pangaea caused an increase in volcanic activity as tectonic plates pulled apart and slammed together, and many of the mountain ranges that we know today were created during those geological upheavals.

In Argentina, where the Carnotaurus lived, the climate would have been warm and dry. The area would have been covered by subtropical forests and open, grassy badlands.

History and Discovery of Carnotaurus

Only one specimen of the Carnotaurus has been uncovered, and it was found in 1985 by Joseph F. Bonaparte in the La Colonia Formation of Chubut, Argentia. The skeleton was remarkably complete, missing only small portions of the tip of the tail and portions of the lower legs. What excited paleontologists most about the remains of the Carnotaurus were the remarkably detailed skin impressions that represented almost the entire right side of the animal’s body. These impressions allowed scientists to study the strange tubercles that covered the body of the Carnotaurus, and led them to the conclusion that Carnotaurus was not covered in feathers, as many dinosaurs were.

Significance of Carnotaurus in History

Because this is the only Carnotaurus fossil to have yet been discovered, Bonaparte’s contribution to paleontology brought a new species to light. The fossilized remains of the Carnotaurus are one of the most complete specimens discovered to date. The fact that the skeleton was almost entirely intact, along with the discovery of such detailed fossilized skin impressions was a remarkable discovery that has allowed scientists to glean deep insights into the life of the dinosaur itself.

Additionally, the Carnotaurus and other dinosaurs in its family (Abelisauridae) have helped to prove the theory of plate tectonics and continental drift. As mentioned above, the world’s continents began as one large landmass, known today as Pangaea, which then broke into the continents that we know today. Dinosaurs of the family Abelisauridae, which have now been found in Madagascar, Argentina, and India, help to demonstrate that these animals were once located in the same vicinity (when the continents were one landmass) and then evolved separately as they became isolated from on another (as the continents drifted apart over time).

The Importance of Carnotaurus

So, in a very real way, the strange-looking Carnotaurus holds a special significance in history. As one of the most well-preserved specimens we have to date, Carnotaurus provides a unique opportunity for study, and as the only fossil of its kind, it has brought to light a new species of dinosaur that may have otherwise gone undiscovered.