305 Million Year Old Arachnid Holds Clues To The Origin Of Spiders

Posted: Mar 31 2016, 1:10am CDT | by , Updated: Mar 31 2016, 11:19pm CDT, in News | Latest Science News

305 Million Years Old Arachnid Hold Clues to the Origin of Spiders
Credit: University of Manchester

The fossil of an ancient arachnid marks the bridge between early arachnids and modern spiders.

Researchers have discovered a 305 million year old fossilized creature that looks almost like a spider, but it is not.

The creepy ancient arachnid once lived in the part of what is now eastern France and was ‘residing’ the Nation Museum of Natural History in Paris since it was first discovered in 1980s. The reason was that the body of the ancient creature was partially visible as it was encased in ironstone. Attempting to remove that thick case would simply mean damaging the fragile fossil. Therefore, researchers decided to leave it until they get advanced technology to examine the fossil and to see what’s inside the stone.

Now thanks to modern technology and high resolution 3D scans, researchers were able to analyze the animal without splitting it apart and getting the first look at ancient eight-legged ‘almost spider.’

“By CT scanning it, you can actually extract the full front half of the animal from the rock, to try and better understand its anatomy.” Study co-author Russell Garwood from University of Manchester told BBC.

“This fossil is the most closely related thing we have to a spider that isn’t a spider.”

The spider, named Idmonarachne brasieri, lived approximately 305 million years ago, meaning that creature was crawling on the Earth before the existence of dinosaurs. It was just 1.5 centimeters across and had a lot in common with modern spiders like eight legs and fangs. But they were missing one key aspect – the organs for producing silk. However, they had a tail-like appendage, which has been found on other arachnids of same time. They also had powerful jaws, further making them unique species.

“Our new fossil occupies a key position in the evolution of spiders. It isn't a true spider, but has given us new information regarding the order in which the bits of the anatomy we associate with spiders appeared as the group evolved." Garwood said in a statement.

These weird arachnids somehow went extinct in the past millions of years but their close relatives continued to evolve into modern spiders. This ancient spider-like creature may hold clues to the origin of modern spiders and may prove a missing link between early arachnids and present day spiders.

“Our creature probably split off the spider line after (Attercopus), but before true spiders appeard.” Garwood said.

Attercopus is an extinct genus of arachnids that lived some 80 million years ago. They could produce silk but not had spinnerets that allow spiders to weave web.

To make sure that the fossil did not have spinnerets, necessary for spinning silk, researchers examined it by using a Diamond synchrotron which enables to see tiny objects more clearly through high-powered X-rays.

Researchers found no evidence of a hole close to abdomen where this silk producing organ could lie, showing that the arachnid was not quite a spider but was very close to being one.

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<a href="/latest_stories/all/all/47" rel="author">Hira Bashir</a>
The latest discoveries in science are the passion of Hira Bashir (). With years of experience, she is able to spot the most interesting new achievements of scientists around the world and cover them in easy to understand reporting.




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