(NEWSWEEK) — The rare frilled shark is considered a “living fossil,” because evidence of its existence dates back to at least 80 million years ago. This summer, researchers found one alive and thriving off the coast of Portugal, adding yet more clues about the resilience of this ancient sea creature.

The shark was discovered off the Algarve coast by researchers who were working on a European Union project in the area, the BBC reported. The aim of the project was to “minimize unwanted catches in commercial fishing,” the researchers told SIC Noticisas TV, as the BBC noted. but the team unknowingly unearthed one of the rarest and most ancient animals on the planet.

Scientists believe the frilled shark has remained the same, both inside and out, since the Cretaceous Period, when the Tyrannosaurus Rex and Triceratops still roamed the planet.

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