Thursday, December 10, 2020

New 'sea dragon' species discovered by amateur fossil hunter off English coast

A British fossil hunter has found a previously unidentified "sea dragon" on the southern English coast.
© Megan Jacobs An artist's impression of the new "sea dragon," Thalassodraco etches.

By Jack Guy, CNN 1 hour ago

Steve Etches unearthed the well-preserved ichthyosaur fossil in limestone on the Jurassic Coast in Dorset. He thought the fossil was so unusual that he gave it to experts at the University of Portsmouth, southern England, to study.

Megan Jacobs, a researcher at the University of Portsmouth and a PhD student at Baylor University, Texas, who has spent years working on ichthyosaurs, identified it as a new genus and species.

The two-meter long ichthyosaurus, which lived 150 million years ago, has been named the "Etches sea dragon" (Thalassodraco etchesi).

Etches said in a press release published by the University of Portsmouth Wednesday that he was honored the discovery was named after him.

"It's excellent that new species of ichthyosaurs are still being discovered, which shows just how diverse these incredible animals were in the Late Jurassic seas," Etches added.

Scientists have now identified five species of ichthyosaur from the Late Jurassic period in the UK.

They are known as sea dragons because of their usually large teeth and eyes.

Fossils of ichthyosaurs from this period are rare, according to Jacobs, but this one was well-preserved because it settled in a very soft seafloor when it died.

This meant the front part of its body sunk into the mud, protecting it from scavengers that ate the tail end.

"Thalassodraco etchesi is a beautifully preserved ichthyosaur, with soft tissue preservation making it all the more interesting," said Jacobs in the press release.

Ichthyosaurs were highly adapted marine predators with big eyes, streamlined bodies and lots of conical teeth for catching fish.

The newly identified species has a deep ribcage, small flippers and smooth teeth, which mark it out from other ichthyosaurs.

"It almost looks like a barrel with tiny little flippers sticking out," Jacobs told CNN.

Thalassodraco etchesi likely would have glided through the water using its tail for propulsion rather than its fins, added Jacobs, and its deep ribcage correlates with large lungs which would have allowed it to dive deep under water.

The newly discovered species has even larger eyes than other ichthyosaurs, covering almost a quarter of its whole skull, which would have allowed it to see in low light conditions deep underwater, said Jacobs, who explained that its tiny smooth teeth were probably used to catch soft prey such as squid.

This is the smallest ichthyosaur found so far. The largest known ichthyosaur lived in North America during the Triassic period and had skulls measuring almost five meters in length -- 10 times larger than the Thalassodraco etchesi.

The fossil will be displayed at the Etches Collection, a museum in Dorset which also houses Etches' many other discoveries.

The research was published in the journal PLOS ONE on Wednesday.
© Carla Cook/Etches Collection Steve Etches pictured with a drawing of the newly identified Thalassodraco etchesi.


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