Jurassic colony found in Pacific Ocean
Biologists from the French Museum of Natural History, exploring the South Pacific, have discovered a species of sea creatures previously unknown to science. These are starfish (ophiuras), according to Proceedings of the Royal Society B.
The creature, called Ophiojura exbodi, has eight “tentacles” about 10 centimeters long. Each of them is covered with rows of sharp thorns.
The Ophiur colony lived on a seamount, far from other ecosystems. Scientists came to the conclusion that evolution for them seemed to have stopped – they have not undergone any changes over the past 180 million years, that is, since the early Jurassic period.
Ophiur was spotted at a depth of 1,600 feet (over 480 meters) at the summit of Bank Duran, a seamount in the South Pacific. Scientists examined a fragment of their tentacles under an electron microscope. The study showed that the plates of the limb are connected in a chain, forming a skeleton. Each of them had a pair of holes: a nerve hole and a hole for the attachment of muscles. At the same time, the tentacles were very porous.
The structure of the starfish seemed very unusual to scientists. They could not find analogues among modern species. The picture became clearer when scientists compared the sample to microscopic early Jurassic fossils found in northern France.
“He looked exactly the same,” noted paleontologist Ben Tui.
Obviously, Ophiojura exbodi is the rarest relict species. DNA analysis showed that it separated from its closest relative 180 million years ago. Scientists have suggested that the place where it was found (seamounts in the Pacific Ocean) may be a reserve of as yet undiscovered marine species and living fossils, and an expedition should be equipped there.
Earlier it was reported that “living fossils” were found in the Pacific Ocean. They were thought to have become extinct 273 million years ago.