A Sea Turtle Stampede Possibly Triggered by an Ancient Earthquake

Around 80 million years ago, a seismic event appears to have caused a large group of sea turtles to frantically move across the seafloor. Evidence of this ancient disturbance was discovered in 2019 by free climbers on a steep cliff overlooking the Adriatic Sea, a location generally off-limits due to rockfall hazards. They spotted a rock slab marked with unusual imprints and photographed it.

One climber later shared the images with Paolo Sandroni, a geologist and fellow climber at Italys Marche region Multi-Risk Functional Center. Sandroni and his team examined the site both on foot and using drones, uncovering more than 1,000 paddle-shaped fossilized footprints embedded in limestone, some of which had broken away and fallen to the beach below. This limestone originated from sediment once lying on a shallow seabed.

The footprints were dated to the Cretaceous period, roughly 83 to 80 million years ago, a time when sudden climatic changes, possibly linked to an asteroid impact, may have intensified seismic activity. Sandroni and colleagues suggest that the prints reflect a mass movement of sea turtles startled by an earthquake, as reported in Cretaceous Research.

Fossilized footprints from ancient seabeds are rare, as they are seldom preserved. The team believes these prints survived because sediment displaced by the quake quickly covered them. Considering the prehistoric marine fauna, potential candidates for these flipper marks included large extinct reptiles such as mosasaurs or plesiosaurs, along with sea turtles. Given the social and migratory behavior of sea turtles, they were deemed the most plausible trackmakers.

However, some experts remain skeptical. Anthony Romilio, a paleontologist at the University of Queensland, noted that the patterns do not resemble the spacing or anatomy typical of sea turtle flippers, suggesting the impressions could have non-biological origins. Despite this, the research team plans to collaborate with trace fossil specialists to further investigate these intriguing formations.

Author: Olivia Parker