About 70 million years ago, a fearsome reptile prowled the plains of what we now call Patagonia, South America. Despite many points in common with its current descendants, “Kostensuchus atrox”, that is its name, was distinguished by its size of 3.5 meters and its 250 kilos of muscles, reports the New Scientist magazine. According to paleontologists, it had all the weapons of a predator capable of attacking large prey, even medium-sized dinosaurs. Its discovery sheds light on a little-known part of the ecosystem at the end of the Cretaceous.
The most striking feature of this animal is its teeth. More than fifty sharp teeth, some exceeding five centimeters in length, lined its mouth. Their crenellated appearance, comparable to the blades of a meat knife, reveals an obvious ability to shred muscles and bones. These formidable natural weapons allowed Kostensuchus to quickly carve up its prey, an essential quality for dominating competition in an environment where other large predators reigned.
It was in March 2020 that paleontologists unearthed the fossil of this atypical crocodilian. The marvelously preserved specimen presented a complete skull and several skeletal elements, a real boon for research. Its name combines a reference to the Patagonian wind (kosten), the Egyptian crocodile-headed god (Souchos) and the Greek “atrox”, meaning fierce.
Terrestrial rather than aquatic?
Unlike modern crocodiles with long, flat snouts, Kostensuchus sported a massive, enlarged head suited to immense biting power. Its more elongated limbs suggest increased mobility on dry land, making it closer to a terrestrial rather than strictly aquatic hunter. This unusual morphology testifies to its adaptation to a hybrid lifestyle, capable of surprising both on the shore and in the water.
Specialists point out that its snout, whose nostrils opened forward, did not allow prolonged immersion like its current cousins. This confirms its role as more terrestrial than amphibious. With a jaw shaped to exert exceptional pressure, Kostensuchus could rise to the top of the food chain. Predators and prey of the time had to deal with its presence, fearing the power of its jaw.
Kostensuchus atrox belongs to the group of peirosaurids, now extinct, whose last representatives were wiped off the map during the great mass extinction, 66 million years ago. If the emblematic dinosaurs attract attention, these extinct crocodilians remind us that they shared the territory with other equally impressive predators. This discovery sheds light on the richness and diversity of life forms at the end of the Cretaceous, just before nature redistributed the cards.
