A peculiar ancient-looking shark "with unusual features" was captured by a Portuguese trawler doing research off the coast of Algarve, southern Portugal, BBC reports, citing the local media outlet Sic Noticias TV.
This prehistoric deep-ocean dweller belongs to a notoriously elusive species of eel-like sharks called frilled sharks, or Chlamydoselachus anguineus — one of the rarest and most ancient creatures on the planet.
Referred to by the Portuguese scientists as a "living fossil," the frilled shark has remained virtually unchanged since this species shared the planet with dinosaurs. Remains of Chlamydoselachus anguineus have been dated back 80 million years to the Cretaceous period when Tyrannosaurus Rex and Triceratops still ruled the Earth.
According to the Portuguese news outlet, the researchers aboard the trawler were working on a European Union project aiming to "minimize unwanted catches in commercial fishing" when they fished out the mysterious shark by chance in the waters near Portimao, Algarve.
The captured frilled shark — a male, measuring 4.9 feet in length — was fished in August by a net set up at 2,300 feet below the surface, said researchers at the Portuguese Institute for the Sea and the Atmosphere. However, Chlamydoselachus anguineus are known to venture to even greater depths, of up to 4,200 feet, and they can grow to be 6.5 feet long.Secluded in the vast depths of the Atlantic and the Pacific, frilled sharks are seldom seen in their natural habitat and have been only occasionally spotted off the coasts of Australia, New Zealand, and Japan. This was the case in 2007, when a Japanese fisherman stumbled upon a live specimen — a 5.2-foot-long female which survived for just a few short hours, after being found dying at the surface.
This prehistoric shark's most striking feature is its unique mouth, sporting more than 300 teeth displayed in a frilled, or ruffled, arrangement over 25 rows. Professor Margarida Castro, from the University of the Algarve, told Sic Noticias TV this unusual adaptation was explicitly evolved "to trap squid, fish and other sharks in sudden lunges." This is where the frilled shark gets its name, Castro explained.
Another primitive trait of this ancient deep-dweller, dubbed a "monster of the deep" by Portuguese reporters, is the fact that frilled sharks have either six or seven gill slits — unlike all the other shark species, which only have five.
Although it's been around for quite some time, the species wasn't discovered until the late 19th century, when Samuel Garman first saw it in 1884. Frilled sharks are also said to have inspired sailors' famous tales of "sea serpents," on account of their snake-like movements in the water.
Newsweek reports this prehistoric shark feeds mainly on cephalopods, a class of mollusks that includes squids and octopuses. Yet "its biology and ecology are little known," notes a news release by the Alliance of Mediterranean News Agencies describing this chance encounter.
What we do know is that Chlamydoselachus anguineus have a rather uncomplicated anatomy. According to a Japanese study, the most likely explanation for the frilled shark's "deceptively simple and poorly calcified" skeleton is the scarcity of nutrients found in the deep-sea habitat in which the species resides. It is also probably the reason why this prehistoric shark rarely grows longer than 6.5 feet.
Even though the Independent mentions some scientists have accidentally cut their fingers while examining its teeth, the frilled shark is no threat to humans and has rarely been encountered alive.[Featured Image by Awashima Marine Park/Getty Images]