Rock climbers in Italy accidentally discovered evidence of an 80 million-year-old sea turtle stampede
In Italy, climbers have stumbled upon evidence of what appears to be a stampede of sea turtles that took place nearly 80 million years ago. Now, new research suggests these ancient marine reptiles were fleeing an earthquake.
The climbers recognized the importance of their discovery because the grooves in the rock face of Monte Cònero overlooking the Adriatic Sea reminded them of others who had made securities earlier that year. These grooves had been discovered in another part of the same regional park and were attributed to a Cretaceous marine reptile digging its paddles into the seabed. They consulted Paolo Sandroni, a fellow climber and geologist, who made contact with Alessandro Montanaridirector of the Coldigioco Geological Observatory (OGC).
Sandroni and another team member returned to collect rock samples and document the site using a drone.
Hundreds of these traces are located on a layer of Scaglia Rossa limestone in Cònero Regional Park, a formation that has been studied extensively for decades and preserves millions of years of deep-sea sedimentation, Montanari, co-author of the study, told Live Science.
What is now part of a mountain was once a deep sea floor folded and pushed upward by tectonic forces millions of years ago, he explained. Rock samples collected immediately above the tracks and analyzed by the team reveal important clues about the locations of the tracks and the history behind them. For example, they suggest that sea turtles lived about 79 million years ago during the Late Cretaceous and indicate that the limestone was part of an underwater mud avalanche triggered by a earthquake.
The abundant seismic activity in this formation is also supported by decades of the collective study. Thin sections of rock samples reveal microfossils of organisms that live along the seafloor, suggesting a seafloor environment hundreds of meters deep.
Normally, the tracks left by animals would be erased by currents on the sea floor and “worms, clams and [other] “They basically garden on the seabed,” he noted. But an earthquake caused an underwater avalanche minutes after the tracks were created, preserving them, he said.
The only vertebrates large enough to make these tracks in the late Cretaceous were marine reptiles such as sea turtles, plesiosaurs and mosasaurs. The latter two are thought to have been largely solitary, but if the behavior of ancient sea turtles mirrored that of some current species, the researchers said, then it’s possible that they foraged close to shore or left the water to lay their eggs. Either way, an earthquake caused them all to flee at once, the team suggested in the study, forcing some of the turtles to swim into the water above toward the open sea, and others to run away. closer towards the deeper seabed. The impending underwater avalanche propelled them even further from the path.
Michael Bentonprofessor of vertebrate paleontology at the University of Bristol in the United Kingdom, who was not involved in the research, said the study clearly showed the geological context, but he questioned which animal left the tracks.
“The tracks are unusual because they appear to show underwater barges, where the two forelimbs enter the sediment together and the animal moves forward,” he told Live Science. Most vertebrates tend to “walk or swim with limbs out of order” rather than putting two limbs down at the same time, he said. “Sea turtles generally have a very efficient swimming pattern,” he said, “a bit like underwater flight, where the front paddles swing around,” similar to a figure-eight pattern, which doesn’t seem to match the tracks found. He also wonders why they wouldn’t “just leave the seabed and swim.”
Montanari said that while the footprints would benefit from further research, it is clear, geologically, that there was an underwater avalanche triggered by an earthquake. He said he hoped their work would inspire fossil experts to study the site further.
