The marine predator

  • Name: Brachauchenius
  • Diet: Carnivorous
  • Weight: 9 tons
  • Period: Cretaceous
  • Found In: United States and Colombia

Who was the Brachauchenius?

The Brachauchenius was a marine reptile that inhabited the great seas of Pangea that occupy the present American continent during the period known as the Lower Cretaceous (130-90 million years ago). Its name means “short neck”, and it is a reptile that reached 12 meters long, of which only its skull, similar to that of a crocodile, measured 1.50 meters, reaching an estimated weight of 9 tons.

The Brachauchenius is a reptile included in the Pliosauridae family, in which all its members are characterized by having a large body with 4 fins, a small caudal tail and a skull with an elongated nose. The pliosaurs should not be confused with pleriosaurs, since the latter had a long neck, nor should they be related to the Mosasaurus, since they belong to different families and did not live together.

A characteristic of the Brachauchenius is what his name indicates, he had a short neck. The rest of the species in the group had a not very long neck, like the famous Liopleurodon, but it was much more mobile.


It had large and powerful jaws similar to those of a crocodile, but with a triangular shape (top view) and large temporary pits that allowed a better grip by the muscles, which in turn gave it greater bite power (current studies place it at a power of 5-6 tons of pressure, 2 times greater than the estimated for Tyrannosaurus).

Adaptations to the aquatic environment of the Brachauchenius

Their jaws were prepared to be the dominant predator of the warm waters of the Cretaceous, but not only because of their powerful bite but also because of a series of neurovascular systems (combination of vascular system with sensitive or neural). This system consisted of a series of connections between blood and neurons under the skin of the nose, which gave it a great sense to detect the slightest vibrations in large bodies of water.

One characteristic that has been attributed to virtually all marine reptiles is oviparism. This process consists of keeping their offspring in eggs but inside the mother’s uterus, and only when they break the shell do they leave the uterus.

This characteristic of oviviparism was observed by a famous fossil of Ichthyosaurus in which it is observed how a calf is giving birth, and it has been related to all marine reptiles because it is a method to keep their calves safe, and when they go out to open sea they are already prepared to survive.