The eight-armed, pig-nosed brittle stars found in the depths of the South Pacific have their roots in the days of the dinosaur.
The brittle stars, which are just 1.1 inches (3 cm) in diameter and about 3 inches (8 cm) long arm, represent a new family of relatives of these starfish. One group has members dating back 180 million years. jurassic period.
Fragile stars may lurk in environments 1,180 feet to 1,837 feet (360 to 560 meters) deep, which hasn’t changed much over millions of years, said Tim O’Hara, head of invertebrate research at the Victoria Museum in Mel. Burn Australia The tropics at this depth appear to be a ripe spot for discovering evolutionary remains, he said. or surviving species from a very ancient group of organisms
“Maybe because the tropical environment is so pristine. Dating back to the age of dinosaurs And it hasn̵
7;t changed much,” O’Hara told Live Science. “This makes Some ‘living fossils’ can persist in our time.”Related: Ancient Footprints to Tiny ‘Vampires’: 8 Rare Fossils
(star) fish in a tank
O’Hara discovered the fragile star in 2015 in an unidentified cask stored in the French National Museum of Natural History in Paris. The sample was collected in 2011 during a trip to New Caledonia. French territories in the South Pacific Scientists have used large nets called barrel trawls to scope samples from the seafloor of the volcanic ridge Banc Durand and allow new brittle stars to appear. The example is weird with eight arms instead of five or six. This is normal for fragile stars. It has a long jaw under its body and sharp teeth. And its arms contained strange skeletons that looked as though they were made up of dozens of tiny pig noses snapped together.
“At first sight I could see that it was different from the other fragile stars. that I’m watching,” Ohara said.
After sequencing the samples DNA, O’Hara and his colleagues realized that fragile stars are not closely related to known echinoderm species. This group includes previously known fragile stars, starfish, and other symmetrical stars such as the dollar.
jurassic star
That’s when study co-author Ben Thuy Paleontologist at the Luxembourg National Museum of Natural History Realizing that he had seen bizarre motifs on fragile stars’ arms before, he didn’t understand why they looked familiar, O’Hara said, but then he saw photographs of similar fossils found in the sector. North of France, where he had posted scientific posters many years ago.
Anatomical resemblances reveal that fragile stars have relatives dating back 180 million years when supercontinents. Pangea is breaking up and opening up new oceans The researchers created a new family, which they dubbed Ophiojuridae, to fit these new species. The name comes from the word “Ophio,” which is the ancient Greek word for “serpent,” and comes from the European Jurassic Mountains where Jurassic geology was first defined.
They named the living species. Ophiojura exbodi; With “exbodi” meaning an acronym for a scientific expedition that discovered fragile stars.
They might name it. A fragile star may feed by extending its arm into the water to capture plankton, such as a small shrimp. A layer of mucus may cover the arm. Allowing it to cling to the prey, O’Hara adds that the extra sharp parts on the arm act like a meat hook to trap plankton. The rows and rows of sharp teeth could be used to tear the victim, he said.
The research appears June 16 in the journal Proceedings of the Royal Society B. O’Hara is still exploring New Caledonia. Hopefully it won’t be the last living fossil of the dinosaur age to be found in the region.
Originally published on Live Science.
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