Santiago, Jul 26 (EFE).- A joint expedition made up of Chilean and Argentine scientists has publicized their discovery of the fossilized remains of a crocodile some 148 million years old in the Patagonian mountains in southern Chile, one of the few crocodiles ever found to have lived on dry land along with the dinosaurs.
This new species, unknown until now, was discovered on a 2014 expedition into Chile’s Aysen region, but the results were only recently published in the prestigious Scientific Reports magazine, part of the Nature group, after years of research.
Dubbed Burkesuchus mallingrandensis, the specimen occupies a key spot in the history of crocodiles, as analysis of the cranial structure and the back feet revealed, and it can be considered the ancestor of modern crocodiles, Chile’s Andres Bello University, one of the institutions participating in the investigation, reported in a communique.
The find was made near the Mallin Grande enclave, where there is a site containing the fossilized remains of Jurassic reptiles who lived some 148 million years ago.
Already uncovered at that site in 2004 were the remains of a herbivorous dinosaur called Chilesaurus diegosuarezi, which spurred a number of other teams to probe the region headed by researchers from Andres Bello University and the LACEV comparative anatomy and evolution lab of Argentina’s Bernardino Rivadavia Natural Sciences Museum.
Crocodiles appeared at the beginning of the Jurassic period, almost at the same time as the first dinosaurs, and in just a few million years they had invaded the marine environment to become top-level predators of fish and other aquatic creatures.
HoWever, knowledge is still scanty about land-dwelling crocodiles on the global scale, according to LACEV head Fernando Novas, a researcher with Argentina’s National Council for Scientific and Technical Research (Conicet).
“Jurassic crocodiles that lived on dry land did not exceed the size of a housecat and, in contrast to their terrifying marine cousins, their diet was based on small invertibrates. We knew nothing in South America about those small crocodiles living in puddles and ponds until we ran across the remains of Burkesuchus,” said the paleontologist in the communique.
The study of the fossilized remains revealed that, when it was alive, Burkesuchus mallingrandensis didn’t exceed 70 centimeters (28 inches) in length.
It walked on four legs, which were angled midway between the vertical legs of crocodiles’ ancestors and those of living crocodiles, which are more splayed out.
Its neck, back and tail were covered with a double line of bony protective plates overlaid with skin.
“Despite the fact that its mandibles and teeth were not preserved, the relatives of Burkesuchus lead one to suppose that it was a predator of small animals, probably invertebrates, which it captured on the banks of the ponds where it lived,” Novas said.
Burkesuchus is located on the crocodile family tree very close to the common ancestor of the Neosuchia (“new crocodiles”), that is to say the crocodiles that are alive today.
This specimen “tells us about the origins of modern crocodiles and how, 150 million years ago, they had begun to modify their anatomy, adopting an amphibious lifestyle,” LACEV researcher Federico Agnolin said.
Burkesuchus was part of a group of reptiles that included the three-meter-long Chilesaurus, big long-necked dinosaurs, relatives of Diplodocus and enormous plant-eating titanosaurs.
The name given to the new specimen means “Burke’s crocodile coming from Mallin Grande” and it was selected in tribute to Coleman Burke (1941-2020), of the United States, who was a lover of Patagonia and of paleontology and who financially supported numerous fossil-hunting efforts, including the expedition that uncovered the species that now bears his name.