A 520-million-year-old sea monster had 18 tentacles in his mouth


The discovery of a fossil showing an ancient sea creature with 18 tentacles around his mouth helped solve a modern-day mystery about the origins of a gelatinous carnivore called comb jelly, reveals a new study.

The "sea monster", until then unknown, which scientists have dubbed Daihua sanqiong, lived 518 million years ago in what is now China. And the extinct animal shares a number of anatomical features with modern comb jelly, a small marine creature that uses what are called rows of combs full of hair-like eyelash fillers for swimming. across the oceans.

The discovery suggests that this new species may be the distant relative of the comb, said lead researcher Jakob Vinther, a paleobiologist at the University of Bristol in the UK. [Photos: Ancient Shrimp-Like Critter Was Tiny But Fierce]

"Thanks to the fossils, we were able to discover the origins of the strange comb jellies," Vinther told Live Science. "Even though we can now show that they came from a very reasonable place, it does not make them any less strange."

This finding, however, sparked a debate. While the discovery of RE. sanqiong It's awesome, it's hard to say if this ancient creature is part of the lineage that produced the comb jellies, said Casey Dunn, professor of ecology and evolutionary biology at Yale University, who did not participate in the study.

"I am extremely skeptical about the conclusions they draw," Dunn told Live Science.

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An enlarged photo of rows of eyelashes on Daihua sanqiong, suggesting that it could be a distant relative from jelly to modern comb.

Credit: Jakob Vinther

Vinther fell on the RE. sanqiong fossil during a visit to colleagues from Yunnan University in China. Scientists showed him a number of fossils in their collection, including the mysterious creature they later named. Daihua sanqiong, which was discovered by the study's co-investigator Xianguang Hou, a paleobiologist at Yunnan University. The name of the genus honors the Dai tribe of Yunnan; "hua" means flower in Mandarin and refers to the flower shape of the creature.

On each of RE. Sanqiong & # 39; s the tentacles are thin, feather-like branches with rows of large ciliary hairs that have probably helped to catch prey. According to Vinther, these hairs caught his attention "because we only find large eyelashes on comb jellies". To swim, the comb jellies move their eyelashes, which then flash in beautiful iridescent colors.

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A living comb jelly, known as Euplokamis. The rainbow iridescence of the creature is caused by the movement of ciliary comb bands on the body of the animal.

Credit: Photography by Alexander Semenov

In addition, RE. sanqiong fossil bears an intriguing resemblance to other known ancient animals, including Xianguangia, another ancient creature with 18 tentacles and sea creatures resembling tulips dinomischus and Siphusauctum.

"To make a short story, we were able to rebuild the whole [early] The line of comb combs, "making anatomical comparisons, said Vinther, is a big problem, because some scientists say that these carnivorous swimmers were among the first animals to evolve on Earth, based 'Genealogical trees and genetic modeling of modern comb combs, but now this international team may have shown that comb jellies have a long lineage that precedes them,' said Vinther.

This newly described lineage suggests that some of the ancestors of comb jellies had skeletons and that their ancient tentacles evolved into combs with the densely packed eyelashes that we see today on comb jellies.

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Illustration of an artist from Daihua sanqiong.

Credit: Xiaodong Wang

The discovery also highlights where these ancient animals are probably sitting on the tree of life. For example, researchers previously thought that Xianguangia was a sea anemone, but she "actually is part of the jelly comb branch," said in a statement the co-investigator Peiyun Cong, professor of paleobiology at the Yunnan University.

These results also show that comb jellies are related to corals, sea anemones and jellyfish, the researchers said. "Those [ancient] The tentacles are the same tentacles that you see on corals and sea anemones. We can find comb jellies on these flower-like animals that lived over half a billion years ago. 39 years, "said Vinther. [Photos: Strange, Eyeless Creatures from the Cambrian Period]

But not everyone agrees with this analysis. While Dunn congratulated the researchers for their detailed description of RE. sanqiong and his proposed parents, some of these creatures have so different body shapes that it's hard to see how they could be related, he said. It is possible that the tulip looking dinomischus and Siphusayctum the creatures are related to each other. But Siphusauctum has ciliary rows inside her body, and the animal is supposed to come after, Galeactena, to these rows on the outside of his body. It's hard to see how this animal would turn away as it evolved, Dunn said. Given that some of these claims are tenuous, the burden of proof is heavier and the researchers are not doing it very well, Dunn said.

"These are exciting animals, no matter how connected they are to each other," Dunn said. "Although I am skeptical that tentacles and rows of combs are counterparts [evolutionarily related]I think as we describe more diversity of these deposits, we will certainly learn a lot more about the evolution of animals. "

The study was published online yesterday (March 21) in the journal Current Biology.

Originally published on Science live.


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