Sarcosuchus

The imperator, also known as "SuperCroc", is by far the largest crocodile ever to exist, making modern crocodiles, caimans and alligators look like runts.

The SuperCroc nickname comes from a one-hour long National Geographic documentary aired in 2001. The producers of the TV channel were not so impressed with the name Sarcosuchus - the Greek word for "flesh crocodile" - and wanted something more striking so that the image would ingrained itself in popular culture.

These super prehistoric crocodiles grew steadily throughout their lives and the largest SuperCrocs reached 40 feet from head to tail. In comparison, the largest crocodile still extant, the Saltwater Crocodile, reaches its maximum size of about 25 feet in about 10 years.

A colossal weight

But the large size of this croc - comparable to that of the aquatic lizard hoffmanii - is not the only trait that makes Sarcosuchus so special. What makes Sarcosuchus so impressive is its titanic weight, which was very similar to that of large carnivorous theropod such as and : it reached more than 10 tons in the largest specimens and between 7 and 8 tons in average adults. It was really a huge beast that rarely felt threatened! The apex predator of ancient times deltas. If Sarcosuchus had lived after the era rather than during the Middle Cretaceous, it would be among the largest terrestrial animals on the surface of the Earth. Its only real competitor for food sources was probably the piscivorous giant aegyptiacus who lived and hunted in the same ecosystems, the same rivers. Although the SuperCroc probably did not feed on , it is likely that it was somewhat territorial and considering its colossal size it must have been able to easily break the neck of a trying to compete for the limited sources of food.

Sarcosuchus was a pholidosaur

Sarcosuchus fossil

Contrary to what its nickname suggests, the was not a direct ancestor of modern crocodiles but rather an obscure type of prehistoric reptiles known as pholidosaurs. In contrast, Deinosuchus, which was almost as large as Sarcosuchus, was an authentic member of the crocodile family although classified as an alligator. For reasons still unknown, pholidosaurs have completely disappeared from the surface of the earth millions of years ago and have left no direct descendants.

Habitat and diet

Cretaceous Morocco Oasis

100 million years ago, North Africa did not look at all like what it is now: an arid place covered by the Sahara Desert. It was a lush tropical oasis crisscrossed with multiple rivers and streams and the home of a very large fauna of giant carnivores. There were so many predators in this area that these ecosystems are often referred to as the most dangerous place on Earth. Sarcosuchus was only one of a wide variety of oversized reptiles that benefited from the natural abundance of this region during the Upper Mesozoic Era. The temperature was hot and humid all year long and there was a whole biodiversity of to keep the crocodiles company.

One would think that such a large and heavy crocodile had to feed exclusively on herbivorous dinosaurs carelessly approaching too close to the rivers to drink, such as the (which weighed about half a ton). If we look at the shape and length of its snout, it seems that Sarcosuchus was feeding almost exclusively on fish, feasting on dinosaurs only when the opportunity was perfect. Gigantic theropods with a similar snout such as were also piscivorous.

The snout of the SuperCroc, an unresolved mystery

The bulbous cavity at the tip of Sarcosuchus' long, narrow muzzle continues to be a mystery to paleontologists. Over the years, several theories have been put forward. It may have been primarily a characteristic of sexual selection: males with larger bulbous cavities were more attractive to females during the mating season. It is also possible that it was an improved olfactory organ allowing the Sarcosuchus to hunt for prey in the dark waters of the deltas, in much the same way that Lorenzini's ampullae allow sharks to orient themselves in the sea. Other more or less vague hypotheses were also emitted: it was a blunt weapon used in intra-specific battles or even a sound chamber that allowed SuperCrocs to communicate with each other over long distances.

Osteoderms of Sarcosuchus

Unlike modern crocodiles that have discontinuous osteoderms - as anyone who dares to venture close enough to observe the breaks between their necks and the rest of their bodies can attest to - the entire body of was covered with these bony plates with the exception of its tail and the front of its head. This arrangement was similar to another pholidosaur from the Middle Cretaceous period, Araripesuchus, and probably had a deleterious effect on the overall flexibility of Sarcosuchus' body.