This sea snake tail, with a diameter of only 3 cm and an arm length of about 8 cm, represents a brand-new starfish family, whose members can be traced back to the Jurassic period1.800 million years ago.

The tail of sea snakes may lurk in the environment of 360~560 meters deep, and it has not changed much for millions of years. Tim O'hara, director of the Museum of Invertebrates at Victoria Museum in Melbourne, Australia, said: "In this tropical depth, it seems to be a mature place to find the evolutionary remains or existing species of very old biological groups."

O 'Hara said: "This may be because the tropical environment is very old, which can be traced back to the dinosaur era and has not changed much so far. This allows some living fossils to continue into our time. "

In 20 15, O 'Hara discovered the tail of a sea snake in a barrel of unknown specimens in the French National Museum of Natural History in Paris. This specimen was collected during the 20 1 1 expedition to the French territory of New Caledonia in the South Pacific. Scientists used a big net called beam net to collect samples from the bottom of a fire ridge called Banc Durand and found this new sea snake tail. This specimen is very strange. It has eight arms, not five or six like a fragile star. It has a long chin and sharp teeth under its body. Its forelimbs have strange bone patterns, which look like the pig mouths of dozens of pigs are closely connected.

O 'Hara said: "Even at first glance, I can see that it is different from all other sea snakes I have ever seen."

After sequencing the DNA of the specimen, O 'Hara and his colleagues realized that echinoderms were not closely related to known echinoderms, including previously known echinoderms, starfish and other symmetrical benthic organisms, such as sand lizards.

Ben Thuy carrizo, a paleontologist at the Luxemburg National Museum of Natural History and co-author of the research report, realized that he had seen this strange pig mouth pattern on the arm of a sea snake before. O 'Hara said: "At first, he didn't understand why these fossils looked familiar, but then he saw a photo, which was strikingly similar to the fossils found in northern France that he posted on the science poster many years ago."

Anatomical similarity shows that the genetic relationship of this starfish can be traced back to10.80 billion years ago, when the supercontinent Pangaea was splitting to form a new ocean. Researchers have created a new family, which they call the Cobra family, to adapt to these new species. The name comes from "Ophio", an ancient Greek word meaning "snake", and also from Jura Mountain in Europe, where Jurassic geology was first defined.

They named the existing species exbodi, which is an acronym for the scientific expedition to discover the sea-tailed snake.

However, they may call it a "shredder" and they may put their arms into the water to catch plankton, such as shrimp. The arm may be covered with mucus, which enables it to stick to its prey. O 'Hara said: "The extra spikes on the arms of these fish are like meat hooks, which can trap plankton passing by. Rows of sharp teeth may be used to shred prey.

At present, O 'Hara said: The investigation of New Caledonia is still in progress, which gives people hope that this will not be the last living fossil of the dinosaur era found in this area.