''Trogloraptor'' is a genus of large spiders found in the caves of southwestern Oregon. It is the sole genus in the family Trogloraptoridae, and includes only one species, ''Trogloraptor marchingtoni''. These spiders are predominantly yellow-brown in color with a maximum leg span of . They are remarkable for having hook-like claws on the raptorial last segments of their legs. ''Trogloraptor'' belongs to one of only three new spider families described since 1990. The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

is in honor of the amateur cave biologist and deputy sheriff Neil Marchington.

Discovery

The spiders were first collected in 2010 by Geo Graening, Neil Marchington, Ron Davis and Daniel Snyder, cave conservationists from the Western Cave Conservancy. They were described in 2012 by a research team consisting of

arachnologists Arachnology is the scientific study of arachnids, which comprise spiders and related invertebrates such as scorpions, pseudoscorpions, and harvestmen. Those who study spiders and other arachnids are arachnologists. More narrowly, the study of sp ...

Charles Griswold, Tracy Audisio and Joel Ledford of the California Academy of Sciences. The male holotype was recovered from the M2 cave near Grants Pass, Oregon, on July 29, 2010. The female holotype was recovered from a cave in

Josephine County Josephine County is one of the 36 counties in the U.S. state of Oregon. As of the 2020 census, the population was 88,090. The county seat is Grants Pass. The county is probably named after a stream in the area called Josephine Creek, which in ...

, Oregon, on September 16, 2010. Lead researcher Griswold claimed that ''Trogloraptor'' might explain the legends of giant cave spiders in the area. The discovery is also notable because only two other new spider families have been described since 1990. The American arachnologist Norman Platnick commented that it was "...as fascinating to arachnologists as the discovery of a new dinosaur is to paleontologists."

Taxonomy

''Trogloraptor'' includes only one species, ''Trogloraptor marchingtoni'', and is the only genus in the monotypic family Trogloraptoridae. It was initially suggested that ''Trogloraptor'' was a primitive member of the six-eyed spider

superfamily SUPERFAMILY is a database and search platform of structural and functional annotation for all proteins and genomes. It classifies amino acid sequences into known structural domains, especially into SCOP superfamilies. Domains are functional, str ...

Dysderoidea. However, ''Trogloraptor'' exhibits several unique features, including primitive respiratory systems, that justify its assignment to a separate family. The family probably diverged from other spiders about 130 million years ago, which would make it another notable relict taxon from

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

. A 2014 study based on ribosomal DNA found that ''Trogloraptor'' fell outside the Dysderoidea and concluded that it should not be included in this

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

. The

is in honor of Neil Marchington. The generic name ''Trogloraptor'' means "cave robber", in reference to the spider's habitat and hooked raptorial tarsi.

Distribution

Additional live specimens recovered in 2010 and 2011 from Oregon were all found deep inside caves. Except for a single juvenile specimen recovered from the understory debris of old growth

redwood Sequoioideae, popularly known as redwoods, is a subfamily of coniferous trees within the family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affini ...

forests of northwest California, none have been found outside the caves. This specimen has different markings than ''T. marchingtoni'' and may represent a new undescribed species. The family Trogloraptoridae may have had a wider distribution given that

redwood forest ''Sequoia sempervirens'' ()''Sunset Western Garden Book,'' 1995:606–607 is the sole living species of the genus '' Sequoia'' in the cypress family Cupressaceae (formerly treated in Taxodiaceae). Common names include coast redwood, coast ...

s encompassed a far greater area in

during the Pliocene (about 5

mya Mya may refer to: Brands and product names * Mya (program), an intelligent personal assistant created by Motorola * Mya (TV channel), an Italian Television channel * Midwest Young Artists, a comprehensive youth music program Codes * Burmese ...

). Other species may still be present in other caves.

Description

Trogloraptor marchingtoni, female tarsus of leg IV

Adult ''Trogloraptor'' have six eyes and a body length of about in males and in females. With its legs outstretched, the spider can reach up to in length. The entire body is yellow-brown, except for a dark brown V-shaped mark on the

cephalothorax The cephalothorax, also called prosoma in some groups, is a tagma of various arthropods, comprising the head and the thorax fused together, as distinct from the abdomen behind. (The terms ''prosoma'' and ''opisthosoma'' are equivalent to ''cepha ...

, the orange-brown chelicerae, and the purple-brown abdomen ( opisthosoma) with a series of faint light-colored chevron markings. The

carapace A carapace is a Dorsum (biology), dorsal (upper) section of the exoskeleton or shell in a number of animal groups, including arthropods, such as crustaceans and arachnids, as well as vertebrates, such as turtles and tortoises. In turtles and tor ...

is pear-shaped with a heart-shaped sternum. The abdomen is oval and sparsely covered with small bristles ( setae). The males possess enlarged piriform pedipalps. The spiders are unique in the flexible and teethed hook-like claws on the last segments ( tarsus) of their legs. These elongated claws resemble those of spiders in the family

Gradungulidae Gradungulidae, also known as large-clawed spiders, is a spider family endemic to Australia and New Zealand. They are medium to large-sized haplogyne spiders with three claws and two pairs of book-lungs similar to Mygalomorphae. Some species build ...

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

and New Zealand, but the two families are only distantly related. Hooked tarsal claws are also present to a lesser extent in the unrelated genera ''

Doryonychus ''Doryonychus'' is a monotypic genus of Hawaiian long-jawed orb-weavers containing the single species, ''Doryonychus raptor''. It was first described by Eugène Louis Simon in 1900, and is known only from the Hawaiian island of Kauai. See also ...

'' of

Tetragnathidae Long-jawed orb weavers or long jawed spiders (Tetragnathidae) are a family of araneomorph spiders first described by Anton Menge in 1866. They have elongated bodies, legs, and chelicerae, and build small orb webs with an open hub with few, wid ...

, '' Hetrogriffus'' of Thomisidae and '' Celaenia'' of

Araneidae Orb-weaver spiders are members of the spider family Araneidae. They are the most common group of builders of spiral wheel-shaped webs often found in gardens, fields, and forests. The English word "orb" can mean "circular", hence the English name ...

Ecology

''Trogloraptor'' spin simple webs with only a few strands, hung from the roofs of caves. Griswold ''et al.'' stated that the claws may have a significant function in capturing prey. Similar to the Nelson cave spider of New Zealand ('' Spelungula cavernicola'', a

gradungulid Gradungulidae, also known as large-clawed spiders, is a spider family endemic to Australia and New Zealand. They are medium to large-sized haplogyne spiders with three claws and two pairs of book-lungs similar to Mygalomorphae. Some species build ...

), ''Trogloraptor'' probably dangle upside down from their webs, snatching at passing flying insects with their claws. However their exact prey remains unknown. Captured live specimens were raised in climate-controlled laboratory conditions in an effort to find out. These specimens were offered moths, crickets and other spiders as food; but these were declined and the specimens starved after two weeks. This may indicate a preference for very specific prey. Like most spiders, ''Trogloraptor'' possess venom glands. However, the venom is not known to be harmful to humans. The spiders themselves are very shy and unaggressive. They immediately flee illumination.

References

External links

Western Cave Conservancy
{{Taxonbar, from=Q18642907 Cave spiders Araneomorphae Monotypic Araneomorphae genera Spiders of the United States Endemic fauna of the United States Biota of Oregon Fauna of the Northwestern United States