Crocodiles from the Cretaceous Period of Korea were on two legs. Several well-preserved pathways created by large crocodiles have been found near the city of Sachon in South Korea, 110 to 120 million years ago (Cretaceous period), the extinct ancestor of modern crocodiles. Surprisingly, the path never contains handprints, and biped walking, in particular, indicates fossil crocodylomorphs that are not known from the path.
Professor Kyung Soo Kim of China National University of Education and his colleagues discovered the well-preserved crocodile path at the Sachon Jae-ri site of the Jinan Formation with clearly defined footprints and localized skin marks.
The tracks are 18 meters to 24 centimeters long, which are more than 3 meters long for the trackmaker’s body. “We were surprised to find out that the tracks represent 3-4 meter long biped animals,” said Professor Kim.
“The footprints were initially thought to have been created by a giant bipolar pterosaur walking on the marshes, now we understand that these were biped footprints,” said Dr. from the University of Queensland. Anthony Romeo said.
“The footprints measure approximately 21 cm, suggesting that the trackers’ feet were approximately the same height as the adult human feet. These were tall animals that were more than 3 meters above our estimate.”
“And although the footprints were everywhere on the site, there were no marks.” Paleontologists initially questioned the absence of handprints on the road, pointing out that modern crocodiles are quadrupeds (four-legged).
“Fossil crocodile footprints are quite rare in Asia, so the abundance of about a hundred footprints was extraordinary,” said Dr. Romilio. “As an animal moves, the hind legs have the ability to enter a handmade print and overprint it, but we have found no evidence of this at these Korean sites.”
“This is also not due to poor conservation, as these fossils are spectacular, they also have fine details of preserved soles and foot scales.” The researchers named the new Batrachopus grandis track, emphasizing the larger size than the much older, shorter 2-3 cm long Batracopus-type tracks, commonly found in the Jurassic of North America.
“No one expected such a large binary crocodile. The Jinju formation is very rich in clues; You can read all of ecology, ”said Professor Martin Lockley of the University of Colorado. Some of the oldest terrestrial adapted crocodile remains contain large species that survived more than 200 million years ago (Triassic period).
And some paleontologists think they may be bipeds. Dr. “The Korean pathways test this hypothesis, at least for the Cretaceous period,” said Romilio. “It also shows that this adaptation was effective for millions of years, even with large, ferocious dinosaurs moving.”