Palaeoperenethis
Encyclopedia
Palaeoperenethis is an extinct monotypic
genus
of Nursery web spider
family Pisauridae, and at present, it contains the single species Palaeoperenethis thaleri. The genus is solely known from the Early Eocene, Ypresian
Okanagan Highlands deposits in the Cariboo
region of British Columbia
, Canada
.
impressions that is currently residing in the paleontological collections in the Royal Ontario Museum
, Toronto, Canada. It is a single 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 Dr. Mark Wilson in his 1977 paper discussing the paleoecology
of the Horsefly Lagerstätte
fossil sites. P. thaleri was first studied by Paul A. Selden and David Penney, with their 2009 type description being published in the journal Contributions to Natural History. The generic
name was coined by P. Selden and D. Penney as a combination of the Greek
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
.
and opisthosoma
are missing, the overall size of Palaeoperenethis thaleri 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
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
, othe 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.
Monotypic
In biology, a monotypic taxon is a taxonomic group with only one biological type. The term's usage differs slightly between botany and zoology. The term monotypic has a separate use in conservation biology, monotypic habitat, regarding species habitat conversion eliminating biodiversity and...
genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of Nursery web spider
Nursery web spider
Nursery web spiders are spiders of the family Pisauridae. They resemble wolf spiders , but they carry their egg sacs by means of their jaws and pedipalps . When the eggs are about to hatch, a mother spider will build a nursery "tent," put her egg sac inside, and mount guard outside...
family Pisauridae, and at present, it contains the single species Palaeoperenethis thaleri. The genus is solely known from the Early Eocene, Ypresian
Ypresian
In the geologic timescale the Ypresian is the oldest age or lowest stratigraphic stage of the Eocene. It spans the time between and , is preceded by the Thanetian age and is followed by the Eocene Lutetian age....
Okanagan Highlands deposits in the Cariboo
Cariboo
The Cariboo is an intermontane region of British Columbia along a plateau stretching from the Fraser Canyon to the Cariboo Mountains. The name is a reference to the woodland caribou that were once abundant in the region...
region of British Columbia
British Columbia
British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...
, Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
.
History and classification
Palaeoperenethis thaleri is known only from one fossil, the holotype, number "ROM31304" consisting of part and counterpartCounter slab
Counter slab and slab are the matching halves of a fossil-bearing matrix formed in sedimentary deposits. When excavated the matrix may be split along the natural grain or cleavage of the rock. A fossil embedded in the sediment may then also split down the middle, with fossil remains sticking to...
impressions that is currently residing in the paleontological collections in the Royal Ontario Museum
Royal Ontario Museum
The Royal Ontario Museum is a museum of world culture and natural history in Toronto, Ontario, Canada. With its main entrance facing Bloor Street in Downtown Toronto, the museum is situated north of Queen's Park and east of Philosopher's Walk in the University of Toronto...
, Toronto, Canada. It is a single adult male individual preserved as a compression fossil
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...
in the fine-grained lacustrian rock and thus has been flattened from its dimensions in life. The compression specimen was mentioned in publication by Dr. Mark Wilson in his 1977 paper discussing the paleoecology
Paleoecology
Paleoecology uses data from fossils and subfossils to reconstruct the ecosystems of the past. It involves the study of fossil organisms and their associated remains, including their life cycle, living interactions, natural environment, and manner of death and burial to reconstruct the...
of the Horsefly Lagerstätte
Lagerstätte
A Lagerstätte is a sedimentary deposit that exhibits extraordinary fossil richness or completeness.Palaeontologists distinguish two kinds....
fossil sites. P. thaleri was first studied by Paul A. Selden and David Penney, with their 2009 type description being published in the journal Contributions to Natural History. The generic
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
name was coined by P. Selden and D. Penney as a combination of the Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
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
Konrad Thaler
Konrad Thaler was an Austrian arachnologist.Peter J. Schwendinger, other Austrian arachnologist, studied with Konrad Thaler, in Innsbruck University.-Tributes:...
, past president of the International Society of Arachnology
International Society of Arachnology
The International Society of Arachnology 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 related animals, and organises an International Congress...
.
Description
Due to the incomplete nature of the type specimen, the carapaceCarapace
A carapace is a dorsal 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 underside is called the plastron.-Crustaceans:In crustaceans, the...
and opisthosoma
Opisthosoma
The opisthosoma is the posterior part of the body in some arthropods, behind the prosoma . It is a distinctive feature of the subphylum Chelicerata...
are missing, the overall size of Palaeoperenethis thaleri 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
Pedipalp
Pedipalps , are the second pair of appendages of the prosoma in the subphylum Chelicerata. They are traditionally thought to be homologous with mandibles in Crustacea and insects, although more recent studies Pedipalps (commonly shortened to palps or palpi), are the second pair of appendages of the...
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
The Trechaleidae are a spider family with 75 described species in 15 genera.-Distribution:Almost all species in this family live in Central and South America...
, othe 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.