Paris, France – Researchers have analyzed with the latest technology an already found fossil in France, which has not been identified due to the complexity of the animal’s position, finding a lost piece in spider’s evolution.

An amateur fossil hunter in the 1980s, Daniel Sotty, was the one to discover the ancient creature in Montceau-les-Mines in eastern France. The rock was placed later at the Museúm National d’Histoire Naturelle in Paris.

Idmonarachne brasieri
Researchers analyzed the fossil of a Idmonarachne brasieri, and found that the species may be key to better understand spider’s evolution. Credit: National Geographic

The species is the closest relative to modern spiders ever discovered and dates back to 305 million years ago. For its analysis, scientists used high-resolution CT scans to create a 3D model of the animal and see what was really inside the rock, as reported by the Christian Science Monitor.

“This fossil is the most closely related thing we have to a spider that isn’t a spider,” said lead author Russell Garwood from the study published in the journal Proceedings of the Royal Society B.

The eight-legged creature was named Idmonarachne brasieri, from the Greek mythological figure Idmon, father of the weaver Arachne who was turned into a spider, and Martin Brasier, a British palaeobiologist who died in a car accident in 2014.

From Idmonarachne to modern spiders

Just the main characteristic that makes spiders, a spider, are the spinnerets. The Idmonarachne was capable of producing silk but not control it, due to the lack of extra appendage needed for its better management.

According to arachnologist Jonathan Coddington of the Smithsonian’s National Museum of Natural History, the results showed that the creature falls along the line of evolution towards true spiders.

The Fossil’s combination of features implies a fairly neat set of transitions to true silk production, Coddington added.

To confirm that the Idmonarachne did not have spinnerets, deeper investigations were needed. The team, instead of using the regular laboratory CT scanner, used a high-powered X-rays of Diamond synchrotron in Oxfordshire.

Source: National Geographic