THE picture above is of one of the five known specimens of Chimerarachne yingi, a newly discovered arthropod that lived 100m years ago, during the Cretaceous period. It is preserved in amber and was found in the Hukawng Valley amber mines in northern Myanmar. It, and one of the other specimens, are described in a paper that has just been published in Nature Ecology and Evolution by Wang Bo of the Nanjing Institute of Geology and Palaeontology, in China, and his colleagues.
Dr Wang thinks Chimerarachne yingi is a spider, albeit an unusual one in that it has a tail. Two further specimens are reported simultaneously in a different paper in the same journal, by a team led by Huang Diying, a colleague of Dr Wang in Nanjing, and Gonzalo Giribet of Harvard University. They think the critter is part of an extinct group, related to but different from spiders, called the Uraraneida, of which tails are characteristic.