With its gaping, tooth-filled mouth and its slender, eel-like body, it’s not hard to see why scientists think the frilled shark may have inspired ancient tales of sea monsters. Looking like something out of a nightmare, the deep-sea creature is rarely seen. But fishers in Australia pulled one up this week.

The frilled shark is often called a “living fossil” because it is thought to have changed little in about 80 million years. The fish also bears a resemblance to ancestor species that lived during the time of the dinosaurs.

On Tuesday, Australian media reported that a fishing trawler pulled up a six-foot-long (two-meter) frilled shark in waters near Lakes Entrance off southeastern Victoria, Australia.

Simon Boag of Australia’s South East Trawl Fishing Association told the Australian Broadcasting Corporation that no local fisher had ever seen the creature before. “It does look 80 million years old,” Boag told the ABC. “It looks prehistoric. It looks like it’s from another time!” (See rare video of another species of “sea serpent.”)

“It has 300 teeth over 25 rows, so once you’re in that mouth, you’re not coming out,” he said.

View Images The six-foot-long (two-meter) shark has a slender body and a mouth full of teeth. Photograph by SETFIA

The shark "was on its last legs" when it made it to the surface, Boag told National Geographic.

Boag said the frilled shark was caught in about 3,300 feet (1,000 meters) of water. The species has previously been found at depths up to 5,000 feet (1,500 meters) but is generally thought to live no deeper than 4,000 feet (1,200 meters).

Australia’s national science agency, the Commonwealth Scientific and Industrial Research Organisation (CSIRO), confirmed that the specimen was a frilled shark.

Frilled sharks are occasionally seen at the surface, mostly when they are sick. Most known specimens have been around six feet (two meters) in length. But the California-based MarineBio Conservation Society says that the netting of a 25-foot-long (7.6-meter) shark related to the frilled shark in 1880 “suggests there may be some giant frilled sharks in the sea that could be taken for sea serpents.”

In 2007 a 5.3-foot-long (1.6-meter) frilled shark was found in shallow water in Japan and transferred to a marine park. It died hours after being caught. (See photos of more deep-sea creatures.)

Correction: An earlier version of this story had a typo in the subhead that stated the sharks "resemble their dinosaur ancestors"; they resemble their dinosaur-era ancestors.