Some things never change, and the frilled shark (Chlamydoselachus anguineus) is one of them.
This living fossil of a sea creature dates back at least 80 million years, and it hasn't changed in 65 million of them. Dinosaurs were still roaming the Earth when the snake-looking shark stopped evolving.
Unlike the dinosaurs, however, the frilled shark continues to live on, swimming through certain areas of the ocean looking decidedly fearsome. As the BBC reports, European Union scientists accidentally caught one this summer off Portugal's southern coast while researching ways to "minimize unwanted catches in commercial fishing." Their specimen measured 5 feet long and was found at a depth of 2,300 feet.
Not much is known about the frilled shark, thanks in no small part to its fondness for the ocean's darkest depths, anywhere from 390 to 4,200 feet below the surface. A Japanese study in 1991 found the shark mostly munches on members of the cephalopod class, meaning octopuses and squid. Lest you think these mollusks have much of a chance against such an ancient creature, the frilled shark has 300 teeth lined up in 25 nice little rows that are perfect for snatching prey.
As for the shark's name, its frills are actually along its gills. Unlike the sharks we're used to seeing, which have separate gills along their sides, the frilled shark's gills are single slits along its sides and each slit is covered with the creature's namesake frills.
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