''Slaugenhopia'' 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 ...

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 ...

dvinosauria Dvinosaurs are one of several new clades of temnospondyls named in the phylogenetic review of the group by Yates and Warren 2000. They represent a group of primitive semi-aquatic to completely aquatic temnospondyls, and are known from the Late C ...

temnospondyl Temnospondyli (from Greek language, Greek τέμνειν, ''temnein'' 'to cut' and σπόνδυλος, ''spondylos'' 'vertebra') or temnospondyls is a diverse ancient order (biology), order of small to giant tetrapods—often considered Labyrinth ...

within the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Tupilakosauridae Tupilakosauridae is an extinct family of dvinosaurian temnospondyls. It contains the genera ''Slaugenhopia'', '' Thabanchuia'', '' Tupilakosaurus'', and possibly ''Kourerpeton''. Tupilakosaurs are known from Texas, Greenland, Russia, and France. ...

. Fossils have been found from the

Early Permian 01 or 01 may refer to: * The year 2001, or any year ending with 01 * The month of January * 1 (number) Music * '01 (Richard Müller album), ''01'' (Richard Müller album), 2001 * 01 (Urban Zakapa album), ''01'' (Urban Zakapa album), 2011 * ''01011 ...

San Angelo Formation The San Angelo Formation is a geologic formation in Texas. It preserves fossils dating back to the Permian period. Along with the Chickasha Formation is one of the two geologically youngest formations in North America to preserve fossils of case ...

Texas Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...

. The

type Type may refer to: Science and technology Computing * Typing, producing text via a keyboard, typewriter, etc. * Data type, collection of values used for computations. * File type * TYPE (DOS command), a command to display contents of a file. * ...

and only species, ''S. texensis'', was named in 1962. It may be closely related to the dvinosaur ''

Kourerpeton ''Kourerpeton'' is an extinct genus of dvinosaurian temnospondyl. Fossils of ''Kourerpeton'' were discovered in a window of a barber's shop in either Bisbee, Arizona, Bisbee or Mesa, Arizona. ''Kourerpeton'' was named in 1976, with the type spec ...

''. ''Slaugenhopia'' was once classified as a trimerorhachid but is now classified as a tupilakosaurid.

Description and history

''Slaugenhopia'' was found from the San Angelo Formation within the Kahn Quarry of Driver Ranch in

Knox County, Texas Knox County is a county located in the U.S. state of Texas. As of the 2020 census, its population was 3,353. Its county seat is Benjamin. The county was created in 1858 and later organized in 1886. It is named for Henry Knox, an American Revol ...

. Although it was known only from fragments, paleontologist

Everett C. Olson Everett Claire Olson (November 6, 1910 – November 27, 1993) was an American zoologist, paleontologist, and geologist noted for his seminal research of origin and evolution of vertebrate animals. Through his research studying terrestrial verte ...

reconstructed the entire skull when he named the genus in 1962. He placed the genus in the dvinosaur family Trimerorhachidae and thought that it was intermediate between the dvinosaurs ''

Trimerorhachis ''Trimerorhachis'' is an extinct genus of dvinosaurian temnospondyl within the family (biology), family Trimerorhachidae. It is known from the Early Permian of the southwestern United States, with most fossil specimens having been found in the Re ...

'' and ''

Dvinosaurus ''Dvinosaurus'' is an extinct genus of amphibious Temnospondyli, temnospondyls localized to regions of western and central Russia during the Middle Permian, middle and late Permian, approximately 265-254 million years ago. Its discovery was first ...

'' based on the shape of the skull. A mandible that was found earlier in Little Croton Creek was also referred to ''Slaugenhopia''. ''Slaugenhopia'' continued to be classified as a trimerorhachid until 1999 when a new dvinosaur called ''

Thabanchuia ''Thabanchuia'' is an extinct genus of dvinosaurian temnospondyl within the family Tupilakosauridae. It is known from the Lystrosaurus Assemblage Zone in Thaba N'chu, Free State, South Africa. The genus contains just one species, ''Thabanchui ...

'' was named from

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...

. ''Thabanchuia'' is a member of the family Tupilakosauridae and shares many similarities with ''Slaugenhopia''. Because of these similarities, ''Slaugenhopia'' is now considered a tupilakosaurid. Defining characteristics of ''Slaugenhopia'' include a notch in the pterygoid bone of the

palate The palate () is the roof of the mouth in humans and other mammals. It separates the oral cavity from the nasal cavity. A similar structure is found in crocodilians, but in most other tetrapods, the oral and nasal cavities are not truly sep ...

called the pterygoid incisure; the wideness of a projection of bone in the palate called the cultriform process, a wide contact between the

parasphenoid The parasphenoid is a bone which can be found in the cranium of many vertebrates. It is an unpaired dermal bone which lies at the midline of the roof of the mouth. In many reptiles (including birds), it fuses to the endochondral (cartilage-derived ...

and basisphenoid bones on the underside of the skull, and uniquely L-shaped

postparietal Postparietals are cranial bones present in fish and many Tetrapod, tetrapods. Although initially a pair of bones, many lineages possess postparietals which were fused into a single bone. The postparietals were Dermal bone, dermal bones situated alo ...

bones at the back of the skull. Another Early Permian dvinosaur called ''Kourerpeton'' is also known from Texas and may be related to ''Slaugenhopia''. Both dvinosaurs have an enlarged

postorbital The ''postorbital'' is one of the bones in vertebrate skulls which forms a portion of the dermal skull roof and, sometimes, a ring about the orbit. Generally, it is located behind the postfrontal and posteriorly to the orbital fenestra. In some ve ...

bone and a small

postfrontal The postfrontal is a paired cranial bone found in many tetrapods. It occupies an area of the skull roof between and behind the orbits (eye sockets), lateral to the frontal and parietal bones, and anterior to the postorbital bone. The postfrontal ...

bone near the eye sockets. They also have similar vertebrae, with ring-like intercentra and small, crescent-shaped pleurocentra. While the posterior margin of the skull is relatively straight in ''Slaugenhopia'', the same margin is curved and irregular in ''Kourerpeton''. ''Kourerpeton'' also lacks the pterygoid incisure of ''Slaugenhopia'', which is characteristic of other tupilakosaurids as well. Based on these differences, ''Kourerpeton'' is probably a basal relative of tupilakosaurids, including ''Slaugenhopia''.

References

{{Taxonbar, from=Q7539002 Dvinosauria Cisuralian temnospondyls of North America Taxa named by Everett C. Olson Fossil taxa described in 1962