''Palaeoperenethis'' is an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unisp ...

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of nursery web spider 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 (geology), age or lowest stage (stratigraphy), stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by th ...

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

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 a ...

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 (North America), caribou that were once abundant in the reg ...

region of

British Columbia British Columbia is the westernmost Provinces and territories of Canada, province of Canada. Situated in the Pacific Northwest between the Pacific Ocean and the Rocky Mountains, the province has a diverse geography, with rugged landscapes that ...

, Canada.

History and classification

''Palaeoperenethis thaleri'' is known only from one fossil, the holotype, number "ROM31304" consisting of

part and counterpart A compression fossil is a fossil preserved in sedimentary rock that has undergone physical compression. While it is uncommon to find animals preserved as good compression fossils, it is very common to find plants preserved this way. The reason fo ...

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 Toronto ( , locally pronounced or ) is the List of the largest municipalities in Canada by population, most populous city in Canada. It is the capital city of the Provinces and territories of Canada, Canadian province of Ontario. With a p ...

, Ontario, Canada. It is an adult male individual preserved as a

compression fossil A compression fossil is a fossil preserved in sedimentary rock that has undergone physical compression. While it is uncommon to find animals preserved as good compression fossils, it is very common to find plants preserved this way. The reason f ...

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 Paleoecology (also spelled palaeoecology) is the study of interactions between organisms and/or interactions between organisms and their environments across geologic timescales. As a discipline, paleoecology interacts with, depends on and informs ...

of the

Horsefly Shales Horse flies and deer flies are true flies in the family Tabanidae in the insect order Diptera. The adults are often large and agile in flight. Only females bite land vertebrates, including humans, to obtain blood. They prefer to fly in sunli ...

Lagerstätte A Fossil-Lagerstätte (, from ''Lager'' 'storage, lair' '' Stätte'' 'place'; plural ''Lagerstätten'') is a sedimentary deposit that preserves an exceptionally high amount of palaeontological information. ''Konzentrat-Lagerstätten'' preserv ...

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 scientific description of a newly encountered species, typically articulated through a scientific publication. Its purpose is to provide a clear description of a new species of organism and explain how it differ ...

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 Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

word ''palaios'' meaning "ancient" and '' Perenethis'', 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, past president of the

International Society of Arachnology The International Society of Arachnology (ISA) promotes the study of arachnids and the exchange of information among researchers in this field. It acts as an umbrella organisation for regional societies and individuals interested in spiders, and rel ...

.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 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 tortoises, the unde ...

and

opisthosoma The opisthosoma is the posterior part of the body in some arthropods, behind the prosoma ( cephalothorax). It is a distinctive feature of the subphylum Chelicerata (arachnids, horseshoe crabs and others). Although it is similar in most respects ...

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

pedipalp Pedipalps (commonly shortened to palps or palpi) are the secondary pair of forward appendages among Chelicerata, chelicerates – a group of arthropods including spiders, scorpions, horseshoe crabs, and sea spiders. The pedipalps are lateral to ...

s 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 araneomorph spiders first described by Eugène Simon in 1890. It includes about 140 described species in 16 genera. They all live in Central and South America except for '' Shinobius orienta ...

, 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