Ancient Earthquake May Have Triggered a Mass Sea Turtle Stampede
About 80 million years ago, an earthquake may have set off a frantic rush of marine animals across a shallow seabed — and traces of that panic may have been preserved in stone along Italy’s Adriatic coast. The unusual fossil impressions were first noticed in 2019 by a group of free climbers on a steep, normally restricted slope above the sea.
The climbers photographed a slab covered with paddle-shaped marks and later showed the images to Paolo Sandroni, a geologist and fellow climber at the Marche Region’s Multi-Risk Functional Center. Sandroni and a colleague surveyed the site on foot and with drones and found more than 1,000 fossilized, paddle-like impressions in limestone, including blocks that had fallen to the beach below.
Geological context: The limestone containing the impressions formed from sediment that once lay on a shallow seafloor. The researchers dated the prints to the Late Cretaceous (roughly 83–80 million years ago), a period when abrupt climate shifts and heightened seismic activity — possibly linked to asteroid-related events — affected marine environments.
“The footprints probably represent a stampede of panicking sea turtles that were mobilized en masse by an earthquake,” Sandroni and co-authors wrote in their paper published in the journal Cretaceous Research.
Why sea turtles? To identify the track-makers, the team considered the marine vertebrates present at the time. Large marine reptiles such as mosasaurs and plesiosaurs existed then but were not typically social. Sea turtles are known to migrate and travel in groups, so the researchers argue they are the likeliest producers of many parallel paddle marks.
Preservation and alternative views: Footprints from ancient seafloors are rare because they are easily erased, but the team suggests a sudden blanket of sediment stirred up by an earthquake could have rapidly buried and preserved the impressions. Not all experts agree: Anthony Romilio, a paleontologist at the University of Queensland, told New Scientist that the impressions lack the spacing, rhythm and anatomical detail expected from turtle flipper strokes and may instead be abiotic (non-biological) structures.
Next steps: The research team plans to collaborate with specialists in trace fossils to test competing explanations and study the prints in greater detail. Whether biological or geological in origin, the discovery highlights how a chance photograph and careful fieldwork can reveal surprising snapshots of ancient environments.
Study source: Cretaceous Research. Initial reporting includes Nautilus and New Scientist.
