An international team of scientists discovered in Santa Cruz, Argentina, a new species of late Cretaceous carnivorous crocodile, named Kostensuchus atrox.
The 70 million-year-old fossil was found near El Calafate, in an area that is becoming one of the most relevant fossil sites in the world for studying the twilight of the Mesozoic Era.
A binational scientific effort to unearth the past
Argentinian and Japanese researchers lead the discovery of a unique species.
The discovery was led by paleontologists Fernando Novas and Diego Pol, from Conicet, along with their Japanese colleagues Makoto Manabe and Takanobu Tsuihiji, from the University of Tokyo. The fossil includes a complete and exceptionally preserved skull, embedded in volcanic rock, which required years of laboratory work for its extraction.
“Freeing the fossil was a challenging task, but it allowed us to reveal an anatomy never seen before,” explained Pol, from the Argentine Museum of Natural Sciences. “We are facing one of the main predators of its time,” he added.
A terrestrial crocodile with a devastating jaw
The new reptile belongs to the Peirosauridae family, which inhabited South America and Africa. It measured over three meters long, with a half-meter skull and a short, robust snout, equipped with over 50 serrated teeth of five centimeters. Its extremely powerful lower jaw allowed it to hunt small and medium-sized dinosaurs.
Unlike modern crocodiles, Kostensuchus atrox would have had a terrestrial or semiaquatic lifestyle, giving it greater stalking and capturing abilities.
A name with cultural roots and fierce symbolism
The name of the new species combines three elements:
- “Kosten“, which means “wind” in the local indigenous language
- “Suchus“, in reference to the Egyptian god with a crocodile head
- “Atrox“, from Latin, meaning “fierce”
This baptism reflects both the Patagonian origin and the predatory nature of the animal.
Paleontology in times of pandemic
The fossil was discovered in 2020, shortly before the onset of the Covid-19 pandemic. “When we returned, we found a deserted city. It was heartbreaking,” recalled Novas, who had to remain isolated for several months in El Calafate with his team.
The location of the fossil began when Conicet technician, Marcelo Isasi, detected dark fragments in a rock, contrasting with the surroundings. This led to the identification of the skull and a large part of the skeleton.
During the lockdown, the scientists continued cleaning the fossil from their homes, demonstrating the team’s commitment to research.
A window into the ecosystem at the end of the dinosaurs
This discovery provides a fundamental piece to understand the biodiversity of the late Cretaceous and the predators that dominated Patagonia before the mass extinction 66 million years ago. Only a few species of crocodiles survived, giving rise to the current forms.
The area near the Perito Moreno glacier presents logistical and climatic challenges, but the team plans to return to further study the post-dinosaur ecosystem.
Cover photo courtesy of Fernando Novas (Azara).
