The frilled shark is a rarely seen “living fossil” that has been around since at least 80 million years ago. This summer, researchers stumbled onto one off the coast of Portugal, providing more information about this resilient, ancient sea creature.
Researchers working on a European Union project off the Algarve coast were aiming to “minimize unwanted catches in commercial fishing.” But in their quest, the team unknowingly found one of the oldest animals on the planet, the BBC reports.
Scientists believe that the frilled shark has not changes since the Cretaceous Period, the time when dinosaurs such as the Tyrannosaurus Rex and the Triceratops roamed the planet. Known as Chlamydoselachus anguineus, the marine animal is incredibly simple and unevolved, primarily because of the lack of nutrients in its deep-sea habitat. A Japanese study on a frilled shark found in Suruga Bay showed that the creature’s diet was mostly composed of cephalopods, which includes squids and octopuses.
The frilled shark lives 390 and 4,200 feet below the surface, which is why it is rarely seen and was not even known to humans until the 19th century, despite having been around for millennia.
This shark from Portugal measured around five feet long, and can grow up to six-and-a-half feet. The sharks have the longest gestation period of any living animals at 42 months, according to the Suruga Bay study. Its physical appearance is somewhere between an eel and a fish.
The frilled shark is named for the appearance of its gills, which are unique in appearance. While other sharks have separate gills, the frilled shark’s first gills stretch across its throat. It has six pairs of gills that have ruffled-looking edges, hence the name.
The deep-sea animal has an unusual jaw shape lined with over 300 teeth in 25 rows. The teeth are lines with dermal denticles, giving the frilled shark a terrifying appearance all around.