Vast ‘fish lizard’ graveyard discovered under melting glacier in Chile could reveal how the ancient ichthyosaurs became extinct

Scientists have discovered a vast graveyard of ancient marine reptiles, hidden under a glacier in Chile, that could change our understanding of how the species lived, died – and ultimately became extinct altogether.

Palaeontologists at the remote site in the southern Torres del Paine National Park said rocks containing nearly 50 complete ichthyosaur fossils were exposed as the vast Tyndall Glacier melted.

The specimens, from four different species of the ancient reptiles whose Greek name means “fish lizard”, lived between the Triassic and Cretaceous periods, which extended from 250 million to 66 million years ago.

Christian Salazar, a palaeontologist and natural history museum curator, said the way the remains had been deposited at the ichthyosaur cemetery was “unique”.

“It's the most recent great find in their history,” he said. “That's going to answer a lot of questions about how they became extinct, where they migrated to and how they lived.”

Wolfgang Stinnesbech, a palaeontologist from the University of Heidelberg in Germany who led the study, told Live Science that the ichthyosaurs, which “look a lot like dolphins today”, were extraordinarily well-preserved.

Only a small number of partial remnants from the ancient reptiles have ever been found in South America before, making this find all the more unusual.

Stinnesbech said these ichthyosaurs hunted for fish and squid-like creatures in flooded caves and canyons near the coastline, and were probably killed by a sudden mudslide to be preserved so well.

Such mudflows due to global warming have been described as one possible cause for the species to become extinct. Stinnesbeck said ichthyosaurs ruled the Earth’s seas at the same time as the dinosaurs and pterosaurs, but that they may well have died out before their land- and air-dwelling counterparts.