Not Actually an Ancient Giant Spider

[Recusant]

For a while, Mongolarachne chaoyangensis was a thing--a very large arachnid from the Lower Cretaceous. Then, after a closer look, it wasn't.

"A 'Jackalope' of an Ancient Spider Fossil Deemed a Hoax, Unmasked as a Crayfish" | University of Kansas

Image Credit: Paul Selden, et al.

Earlier this year, a remarkable new fossil specimen was unearthed in the Lower Cretaceous Yixian Formation of China by area fossil hunters – possibly a huge ancient spider species, as yet unknown to science.

The locals sold the fossil to scientists at the Dalian Natural History Museum in Liaoning, China, who published a description of the fossil species in Acta Geologica Sinica, the peer-reviewed journal of the Geological Society of China. The Chinese team gave the spider the scientific name Mongolarachne chaoyangensis.

But other scientists in Beijing, upon seeing the paper, had suspicions. The spider fossil was huge and strange looking. Concerned, they contacted a U.S. colleague who specializes in ancient spider fossils: Paul Selden, distinguished professor of invertebrate paleontology in the Department of Geology at the University of Kansas.

"I was obviously very skeptical," Selden said. "The paper had very few details, so my colleagues in Beijing borrowed the specimen from the people in the Southern University, and I got to look at it. Immediately, I realized there was something wrong with it – it clearly wasn't a spider. It was missing various parts, had too many segments in its six legs, and huge eyes. I puzzled and puzzled over it until my colleague in Beijing, Chungkun Shih, said, 'Well, you know, there's quite a lot of crayfish in this particular locality. Maybe it's one of those.' So, I realized what happened was I got a very badly preserved crayfish onto which someone had painted on some legs."

[Continues . . .]

[billy rubin]

" . . . onto which someone had painted on some legs??"

that's a palaeontological no-no.

but seriously funny.

[No one]

That's not Boris?

[Sandra Craft]

Why get excited over that when they have bigger ones living now in Australia?