''Palaeoperenethis'' is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

monotypic genus of

nursery web spider Nursery web spiders (Pisauridae) is a family of araneomorph spiders first described by Eugène Simon in 1890. They resemble wolf spiders (Lycosidae) except for several key differences. Wolf spiders have two very prominent eyes in addition to the o ...

family Pisauridae, and at present, it contains the single species ''Palaeoperenethis thaleri''. The genus is solely known from

Early Eocene In the geologic timescale the Ypresian is the oldest age or lowest stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by the Eocene Lutetian Age. The Ypresian i ...

, Ypresian

Okanagan Highlands The Okanagan Highland is an elevated hilly plateau area in British Columbia, Canada, and the U.S. state of Washington (where it is spelled Okanogan Highlands). Rounded mountains with elevations up to above sea level and deep, narrow valleys are ...

deposits in the

Cariboo The Cariboo is an intermontane region of British Columbia, Canada, centered on a plateau stretching from Fraser Canyon to the Cariboo Mountains. The name is a reference to the caribou that were once abundant in the region. The Cariboo was the ...

region of British Columbia, Canada.

History and classification

''Palaeoperenethis thaleri'' is known only from one fossil, the holotype, number "ROM31304" consisting of part and counterpart impressions that is currently residing in the paleontological collections in the

Royal Ontario Museum The Royal Ontario Museum (ROM) is a museum of art, world culture and natural history in Toronto, Ontario, Canada. It is one of the largest museums in North America and the largest in Canada. It attracts more than one million visitors every year ...

, Toronto, Ontario, Canada. It is an adult male individual preserved as a compression fossil in the fine-grained lacustrian rock and thus has been flattened from its dimensions in life. The compression specimen was mentioned in publication by paleoichthylologist Mark Wilson (1977) while discussing the paleoecology of the

Horsefly Shales Horse-flies or horseflies are true flies in the family Tabanidae in the insect order Diptera. They are often large and agile in flight, and only the female horseflies bite animals, including humans, to obtain blood. They prefer to fly in su ...

Lagerstätte fossil site. ''P. thaleri'' was first studied by Paul A. Selden and David Penney, with their 2009

type description A species description is a formal description of a newly discovered species, usually in the form of a scientific paper. Its purpose is to give a clear description of a new species of organism and explain how it differs from species that have be ...

being published in the journal '' Contributions to Natural History''. The

generic Generic or generics may refer to: In business * Generic term, a common name used for a range or class of similar things not protected by trademark * Generic brand, a brand for a product that does not have an associated brand or trademark, other ...

name was coined by P. Selden and D. Penney as a combination of the Greek word ''palaios'' meaning "ancient" and ''

Perenethis ''Perenethis'' is a genus of nursery web spiders that was first described by Ludwig Carl Christian Koch in 1878. Species it contains six species, found in Africa, Asia, Australia, and Papua New Guinea: *'' Perenethis dentifasciata'' (O. Pickard ...

'', a modern Nursery web spider genus. This is in reference to the age of the type specimen and the African-Asian genus which ''Palaeoperenethis'' is similar in appearance to. The specific epithet "''thaleri''" was designated by P. Selden and D. Penney in honor of the late Dr.

Konrad Thaler Konrad Thaler (born 19 December 1940 in Innsbruck, Austria – died 11 June 2005) was an Austrian arachnologist. Peter J. Schwendinger, other Austrian arachnologist, studied with Konrad Thaler, in Innsbruck University. Tributes The specific epit ...

, past president of the International Society of Arachnology.International Society of Arachnology website
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Description

Due to the incomplete nature of the type specimen, 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 ...

and opisthosoma are missing, the overall size of ''Palaeoperenethis thaleri'' is not certain. The general shape of the carapace is indicated in the position and disposition of the legs which suggest a subcircular or polygonal carapace. The placement of ''Palaeoperenethis'' into Pisauridae is based on the shape and structure of the elongated pedipalps which have a brush of bristles along one edge. Several important characters of the family, such as nursery web construction and egg sack care, are not verifiable in the fossil. The presence of ''Palaeoperenethis'' in a lacustrine environment is another feature indicating a placement in Pisauridae. While bristles on the pedipalp are also known in the family

Trechaleidae Trechaleidae (''tre-kah-LEE-ih-dee'') is a family of Araneomorphae, araneomorph spiders first described by Eugène Simon in 1890, and includes about 140 described species in 16 genera. They all live in Central America, Central and South America e ...

, other overall morphology found in ''Palaeoperenethis'' is much closer to Pisauridae. Though the morphology is similar to the modern genus ''Perenethis'' a direct relationship to the genus is unknown, however ''Palaeoperenethis'' is most similar to members of the subfamily Pisaurinae.

References

{{Taxonbar, from=Q3360789 Pisauridae Eocene arthropods Fossil taxa described in 2009 Geology of British Columbia Cenozoic animals of North America Horsefly Shales