You know how horrible it is when you encounter a spider in your house? It instills a kind of fear that's almost totally paralyzing to some people. Well, as scary as spiders can be, it turns out that millions of years ago there was something equally as horrifying. Paleontologists with the Royal Ontario Museum (ROM) have discovered spider ancestor fossils, and let's just say we'll take spiders over this thing any day.
The newly discovered creature, given the Latin name Mollisonia plenovenatrix, is now considered to be the oldest chelicerate, according to a press release from the ROM. It was discovered in the Burgess Shale, located in British Columbia.
Chelicerates are distinguished by the presence of chelicerae, those terrifying pincer things that make them look like they come from a nightmare dimension.
"Before this discovery, we couldn’t pinpoint the chelicerae in other Cambrian fossils, although some of them clearly have chelicerate-like characteristics," lead author Cédric Aria said in the release. "This key feature, this coat of arms of the chelicerates, was still missing." Aria has been a member of the Royal Ontario Museum’s Burgess Shale expeditions since 2012. He is currently a post-doctoral fellow at the Nanjing Institute of Geology and Palaeontology.
This particular species was also one that lived in the water. Imagine stepping into the lake and feeling a few of these things (which were as big as a thumb, by the way) crawling on your feet? No, thanks. The release also describes the creature as having "egg-shaped eyes," as well as "numerous pairs of limbs that could all-together sense, grasp, crush and chew." Sounds delightful.
This particular species is not only an amazing discovery in terms of finding an ancient ancestor to modern arachnids. It also seems to provide more answers about the Cambrian explosion, a "time of uniquely rapid diversification of body forms," according to the release.
Previously, only the exoskeleton of the animal had been described. "It is the first time that evidence of the limbs and other soft-tissues of this type of animal are described, which were key to revealing its affinity," said co-author Jean-Bernard Caron, Richard M. Ivey Curator of Invertebrate Palaeontology at the Royal Ontario Museum in the release.
This newly discovered species will be on display in the ROM's upcoming Willner Madge Gallery, Dawn of Life, which is set to open in 2021.