Part spider, part scorpion creature captured in amber

Feb 07, 2018, 00:54
Part spider, part scorpion creature captured in amber

For now, researchers disagree on the exact placement of the part-spider, part-scorpion critter.

The finding is described in a paper appearing in Nature Ecology & Evolution by an global team including Paul Selden of the Paleontological Institute and Department of Geology at the University of Kansas and colleagues from China, Germany, Virginia and the United Kingdom.

In addition to the tail and the fangs, this new spider has male pedipalps, four walking legs, and silk-producing spinnerets at the rear.

"Gonzalo Giribet at Harvard University in Cambridge, Massachusetts, Diying Huang at the Chinese Academy of Sciences in Nanjing and their colleagues analysed two fossils of the animal dating to about 100 million years ago". The other study details two additional individuals. Happily, their results were close enough that the journal opted to publish both papers. For example, if they discover that these ancient creatures made venom, that could place them more firmly in the modern spider lineage. Comparison with fossils subsequently unearthed showed that this newly classified branch of arachnids differed from spiders - the Araneae - in several structural ways, notably in the positioning of silk-producing spigots, and a tail-like appendage, known as a telson, at the end of the abdomen. Their hindquarters bear spinnerets, the same organs from which living species spin their silken webs.

Although Selden doesn't think these creatures are quite spiders, he acknowledges they certainly share many arachnid-like characteristics.

"We have known for a decade or so that spiders evolved from arachnids that had tails, more than 315 million years ago", Russell Garwood of The University of Manchester, a co-researcher on the study, told the BBC.

"There's been a lot of amber being produced from northern Myanmar and its interest stepped up about ten years ago when it was discovered this amber was mid-Cretaceous; therefore, all the insects found in it were much older than first thought", said Selden.

"It seems to be an intermediate form", Selden said - midway between the spinneret-less A. fimbriunguis and the spiders of today.

True spider or not, this animal might still haunt your dreams tonight.

Anyone who hates spiders won't enjoy the latest major discovery of prehistoric creatures.

Besides having a flagellum or tail - believed to have been used by the invertebrate as a sensory organ - Chimerarachne stands out from much older arachnids of 300 million years ago in having silk-producing spinnerets. In the 1880s, scientists working in Madagascar were surprised to see a new type of "assassin spider" crawling about. "These things appear to be essentially spiders with tails!" says Jason Bond, an evolutionary biologist at Auburn University in Alabama who was not involved with the work. This family contains about 100 species of medium-size spiders that have back plates and spinnerets. It makes us wonder if these may still be alive today. The fossil is extremely well preserved in Burmese amber, and dates back to the Cretaceous period, when the likes of Tyrannosaurus rex, Velociraptor and Triceratops walked the earth.