Spiders are the most successful group of Arachnids and one of the most successful groups of Arthropods, with over 40 000 described species in over 100 families, distinguished by having eight legs, producing silk, and having a venomous bite. The the evolutionary lineage that produced Spiders, separate from other Arachnids, appears in the fossil record in the Silurian, about 420 million years ago; though these earliest 'Spiders', called Trigonotarbids, lacked the ability to make silk. Silk producing Spiders appear in the fossil record in the Devonian, 386 million years ago. Since the evolution of the production of silk, Spiders have evolved to fill a wide variety of ecological niches, colonizing every environment except the polar regions and the oceans.
In a paper published in the journal ZooKeys on 17 August 2012, Charles Griswold of the Arachnology Lab at the California Academy of Sciences, the Department of Biological Sciences at San Francisco State University and Environmental Science, Policy and Management at the University of California, Berkeley, Tracy Audisio of the Arachnology Lab at the California Academy of Sciences, the Department of Biological Sciences at San Francisco State University and the Summer Systematics Institute at the California Academy of Sciences and Joel Ledford of the Arachnology Lab at the California Academy of Sciences and Environmental Science, Policy and Management at the University of California, Berkeley, describe a new species of Spider from cave systems in southwestern Oregon and Northwestern California.
The new species is named Trogloraptor marchingtoni, where Trogloraptor means 'clawed cave dweller' and marchingtoni honours Neil Marchington, a Deputy with the Deschutes County Sheriff's Office and a caver, biologist and conservationist. It is deemed to be sufficiently different from all other described species of Spiders that it is placed in a new family, the Trogloraptoridae, largely on account of the destictive claws on the limbs of the Spiders, which help them to run about on the ceilings of caves.
Trogloraptor marchingtoni. Griswold et al. (2012).