| Kourerpeton Temporal range: Permian or Early Triassic | |
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| Family: | †Kourerpetidae |
| Genus: | †Kourerpeton Olson and Lammers, 1976 |
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Kourerpeton is an extinct genus of dvinosaurian temnospondyl. Fossils of Kourerpeton were discovered in a window of a barber's shop in either Bisbee or Mesa, Arizona. [1] Kourerpeton was named in 1976, with the type and only species being K. bradyi. [2] It was originally assigned to the monotypic family Kourerpetidae, which has been alternatively spelled Kourerpetontidae. [3] [4]
Because it was not found in situ, the provenance and age of Kourerpeton is unknown. The fossils are rumored to have been from the Glen Rose Formation near Glen Rose, Texas. [1] Olson and Lammers (1976) discredited this idea because they noted that the Glen Rose Formation is Cretaceous in age, and therefore not a likely source for a temnospondyl. [a] [2] Several studies have claimed that it is Permian or Early Triassic in age. Warren (1999) suggested that Kourerpeton is from an unknown Guadalupian (Middle Permian) to Early Triassic locality in North America, or possibly even from a locality outside North America. [5] Milner and Sequeira (2004) have proposed that Kourerpeton may have been from the Early Permian San Angelo Formation in Texas, which has also been the source of the tupilakosaurid Slaugenhopia . The San Angelo Formation is in close proximity to the Glen Rose Formation, occurring in a north–south belt across north-central Texas about 80 miles (130 km) west of Glen Rose. [1]
Kourerpeton is usually classified in its own dvinosaurian family, the Kourerpetidae. Milner and Sequeira (2004) suggested that Kourerpeton may be a tupilakosaurid based on similarities with the genus Slaugenhopia. Like Slaugenhopia, Kourerpeton possesses enlarged postorbitals and reduced postfrontals, bones that form the portion of the skull roof above the eye sockets. Both Kourerpeton and Slaugenhopia possess incomplete-ring intercentra, which form the cenra of vertebrae. The pleurocentra, which also comprise the centra, are slender and crescentic in both genera. Unlike Slaugenhopia, Kourerpeton lacks an incisure, or notch, on the pterygoid bone of the palate. In Slaugenhopia, this incisure appears as a deep notch in the posterior margin of the central palate. In Kourerpeton, the posterior edge of the skull table is strongly undulated, and has a medial concavity. This is unlike Slaugenhopia, which has a relatively straight skull roof margin. Based on these differences, Milner and Sequeira (2004) considered Kourerpeton to be a primitive stem-tupilakosaurid. [1]
Temnospondyli or temnospondyls is a diverse ancient order of small to giant tetrapods — often considered primitive amphibians — that flourished worldwide during the Carboniferous, Permian and Triassic periods, with fossils being found on every continent. A few species continued into the Jurassic and Early Cretaceous periods, but all had gone extinct by the Late Cretaceous. During about 210 million years of evolutionary history, they adapted to a wide range of habitats, including freshwater, terrestrial, and even coastal marine environments. Their life history is well understood, with fossils known from the larval stage, metamorphosis, and maturity. Most temnospondyls were semiaquatic, although some were almost fully terrestrial, returning to the water only to breed. These temnospondyls were some of the first vertebrates fully adapted to life on land. Although temnospondyls are amphibians, many had characteristics such as scales and armour-like bony plates that distinguish them from the modern soft-bodied lissamphibians.
Dvinosaurs are one of several new clades of Temnospondyl amphibians named in the phylogenetic review of the group by Yates and Warren 2000. They represent a group of primitive semi-aquatic to completely aquatic amphibians, and are known from the Late Carboniferous to the Early Triassic, being most common in the Permian period. Their distinguishing characteristics are a reduction of the otic notch; the loss of a flange on the rear side of the pterygoid; and 28 or more presacral vertebrae.
Saharastega is an extinct genus of basal temnospondyl which lived during the Late Permian period, around 251 to 260 million years ago. Remains of Saharastega, discovered by paleontologist Christian Sidor at the Moradi Formation in Niger, were described briefly in 2005 and more comprehensively in 2006. The description is based on a skull lacking the lower jaws.
Zatrachys is an extinct genus of large and flat-headed zatracheidid temnospondyl from the early Permian of North America.
Chenoprosopus is a genus of extinct cochleosauridae that lived during late Carboniferous and early Permian periods. Two known species of Chenoprosopus are C. milleri and C. lewisi. Chenoprosopus lewisi was described in the basis of a virtually complete skull with maximum skull length of 95 mm. It is significantly smaller than Chenoprosopus milleri and was differentiated from that taxon by Hook (1993) based on sutural patterns of the skull roof. Hook also mentioned the reduced size of the vomerine tusks differentiated C. lewisi from C. milleri, but the different size of these tusks may be different ontogenetic stages of growth. Many of other cochleosaurids from the same time period have an elongated vomer and wide and elongate choana. However, Chenoprosopus is distinguished by its more narrowly pointed snout and separation between the nasal from the maxilla by the broad lacrimal-septomaxilla contact.
Nigerpeton is an extinct genus of crocodile-like temnospondyl amphibians from the late Permian (Changhsingian) period. These temnospondyls lived in modern-day Niger, which was once part of central Pangaea, about 250 million years ago. Nigerpeton is a member of the Cochleosauridae family, a group of edopoid temnospondyl amphibians known from the late Carboniferous (Pennsylvanian) and early Permian (Cisuralian).
Trematopidae is a family of dissorophoid temnospondyl spanning the late Carboniferous to the early Permian. Together with Dissorophidae, the family forms Olsoniformes, a clade comprising the medium-large terrestrial dissorophoids. Trematopids are known from numerous localities in North America, primarily in New Mexico, Oklahoma, and Texas, and from the Bromacker quarry in Germany.
Microposaurus is an extinct genus of trematosaurid temnospondyl. Fossils are known from the Cynognathus Assemblage Zone of the Beaufort Group in South Africa and the Rouse Hill Siltstone of Australia that date back to the Anisian stage of the Middle Triassic. These aquatic creatures were the short snouted lineage from Trematosaurinae.
Limnarchia is a clade of temnospondyls. It includes the mostly Carboniferous-Permian age Dvinosauria and the mostly Permian-Triassic age Stereospondylomorpha. The clade was named in a 2000 phylogenetic analysis of stereospondyls and their relatives. Limnarchia means "lake rulers" in Greek, in reference to their aquatic lifestyles and long existence over a span of approximately 200 million years from the Late Carboniferous to the Early Cretaceous. In phylogenetic terms, Limnarchia is a stem-based taxon including all temnospondyls more closely related to Parotosuchus than to Eryops. It is the sister group of the clade Euskelia, which is all temnospondyls more closely related to Eryops than to Parotosuchus. Limnarchians represent an evolutionary radiation of temnospondyls into aquatic environments, while euskelians represent a radiation into terrestrial environments. While many euskelians were adapted to life on land with strong limbs and bony scutes, most limnarchians were better adapted for the water with poorly developed limbs and lateral line sensory systems in their skulls.
Almasaurus is an extinct genus of trematosaurian temnospondyl within the family Latiscopidae. It is known from several skulls and some postcranial material found from the Argana Formation in Morocco, which dates back to the Late Triassic.
Acroplous is an extinct genus of dvinosaurian Temnospondyli within the family Eobrachyopidae.
Lapillopsis is an extinct genus of stereospondyl temnospondyl within the family Lapillopsidae. Fossils belonging to the genus have been found in the Arcadia Formation of Queensland, Australia.
Phonerpeton is an extinct genus of dissorophoid temnospondyl within the family Trematopidae that is known from the early Permian of Texas.
Trimerorhachis is an extinct genus of dvinosaurian temnospondyl within the family Trimerorhachidae. It is known from the Early Permian of the southwestern United States, with most fossil specimens having been found in the Texas Red Beds. The type species of Trimerorhachis, T. insignis, was named by American paleontologist Edward Drinker Cope in 1878. Cope named a second species from Texas, T. mesops, in 1896. The species T. rogersi and T. greggi are also from Texas, and the species T. sandovalensis is from New Mexico.
Tersomius is an extinct genus of dissorophoid temnospondyl within the family Micropholidae. It is known from the early Permian of North America.
Slaugenhopia is an extinct genus of dvinosaurian temnospondyl within the family Tupilakosauridae. Fossils have been found from the Early Permian San Angelo Formation in Texas. The type and only species, S. texensis, was named in 1962. It may be closely related to the dvinosaur Kourerpeton. Slaugenhopia was once classified as a trimerorhachid but is now classified as a tupilakosaurid.
Dimacrodon is an extinct genus of non-mammalian synapsid from the latest Early Permian San Angelo Formation of Texas. It is distinguished by toothless, possibly beaked jaw tips, large lower canines and a thin bony crest on top of its head. Previously thought to be an anomodont therapsid related to dicynodonts, it was later found to lack any diagnostic features of anomodonts or even therapsids and instead appears to be a 'pelycosaur'-grade synapsid of uncertain classification.
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. The earliest tupilakosaur, Slaugenhopia, is Early Permian in age while the latest known tupilakosaurs are Early Triassic in age. Derived tupilakosaurs possess embolomerous centra in their vertebrae, which are diplospondylous. They also have a deep notch in the pterygoid bone of the palate. Tupilakosaurs were aquatic, and used an undulatory mode of swimming much like that of eels.
Perryella is an extinct genus of dvinosaurian(?) temnospondyl from the Permian of Oklahoma.
