Researchers announced on Monday the discovery of a strange 100 million-year-old spider fossils. The spider fossils were found trapped in amber. At the origins of the identification of this new spider species are four primitive spider fossils, captured in amber 100 million years ago on the territory of actual Myanmar.
Very well preserved, the specimens are the subject of two different studies published in the journal Nature Ecology & Evolution.
Apart from legs, front claws, and spinnerets organs (appendices used to make silk threads and spiderwebs), this very old spiders also had a short-haired tail similar to the tail of the Scorpions.
The tail could have allowed for environmental detection, according to Paul Selden, of the Institute of Paleontology and the Department of Geology of the University of Kansas, co-author of one of the studies.
Being minuscule, given that each fossil was about 7-8 mm long, including the 5 millimeters of the tail, the animal was called Chimerarachne yingi, a reference to Himera, the hybrid monster of Greek mythology, because it is a curious mixture of old and modern characteristics.
From the point of view of Paul Selden, Chimerarachne yingi would be an intermediate species between modern spiders with spinnerets organs but without the tail, and the very old Uraraneida (an order of arachnids, known as “spider cows”) who lived between the years of 380 and 250 million BC and possessed tails but not spinnerets organs.
Chimerarachne yingi could thus be the arachnid species most similar to modern spiders. According to the researchers, it is even possible that some of this species queens are still present in the Myanmar forests.
But from the point of view of Gonzalo Giridet’s team at Harvard University, who conducted the other study, Chimerarachne yingi would be a Uraraneida itself and would have gotten extinct without leaving descendants.
Emerging on the Earth more than 380 million years ago, spiders are now present across the globe and are divided into not less than 47,000 species, according to scientists. However, the 100 million-year-old spider fossils could change some of the theories regarding the evolution of the spiders.