Although those changes occur slowly and gradually, living beings evolve over time. Therefore, you should not be surprised to learn that millions of years ago, there was a creature that was part spider, part scorpion!
So, I bet spiders we spot these days look much less scary now, don’t they?
It was found trapped in amber discovered in Myanmar. These creatures lived in the bark of resin-producing trees during the mid-Cretaceous period, and as tree sap poured over their bodies, it trapped and preserved their corpses, and amber miners discovered them millions of years later.
The spider has a scorpion tail and as the tree resin was roughly 100 million years ago, the discovery indicates that the family of arachnids could have roamed the Earth for over 280 million years.
Two different teams of researchers discovered four specimens of the insect in the amber markets of Myanmar and published their findings in two separate papers in the journal Nature Ecology & Evolution.
Prashant Sharma, an evolutionary developmental biologist at the University of Wisconsin in Madison who was not involved in the work, explained that the discovery “could help close major gaps in our understanding of spider evolution.”
Greg Edgecombe, an invertebrate paleobiologist at the Natural History Museum in London, commented that “the material is stunning in the quality of its preservation,” and “it throws up a combination of characters that initially seems alien to an arachnologist.”
Several years ago, amber fossil dealers independently showed two paleobiologists at the Nanjing Institute of Geology and Paleontology in China specimens that looked like 5-millimeter-long Uraraneida encased in amber.
The first one, Wang Bo, assembled a team to investigate his two specimens, which they eventually named Chimerachne yingi (“chimera spider” in Latin).
The other one, Huang Diying, created a second team of researchers, to examine his pair of fossils. The two teams didn’t know about each other until they published their results to the same journal.
Yet, as Edgecombe explained, “they draw the same conclusion—that fossil uraraneids, as this group is called, are the closest extinct relatives of spiders.”
The creepy crawler had eight legs, fangs, and silk-producing spinnerets near its rear end, and males had two modified appendages called pedipalps as well.
The arachnid was quite small, only about 2.5 millimeters long, and its tail, called a telson, was twice its body and resembled the one of whip-scorpions or vinegarroons.
Yet, it was probably a sensory organ and was not used for attacking.
Paleontologist and arachnologist Paul Selden of the University of Kansas said:
“Any sort of flagelliform appendage tends to be like an antenna. It’s for sensing the environment. Animals that have a long whippy tail tend to have it for sensory purposes.”
Gonzalo Giribet, an invertebrate biologist from Harvard University and an author on one of the papers, added:
“Take the front of a spider, the end of a vinegarroon and then you put spinnerets on it and that’s our fossil.”