| Perryella Temporal range: | |
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Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Amphibia |
| Order: | † Temnospondyli |
| Suborder: | † Dvinosauria |
| Genus: | † Perryella Carlson, 1987 |
| Species | |
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Perryella is an extinct genus of dvinosaurian(?) temnospondyl from the Permian of Oklahoma.
The type and only species, P. olsoni, was named in 1987 from the Wellington Formation exposures of Noble County, Oklahoma, which is Early Permian in age. [1] It is known from several skulls and partial remains of vertebrae and limbs. The genus name is for the nearby town of Perry, Oklahoma. The specific name honors the American paleontologist Everett C. Olson. A subsequent study by Ruta & Bolt (2006) was based on the further preparation of the cranial material in particular. [2]
Perryella has a melange of different features, which contributes to uncertainty regarding its phylogenetic position (see below). It has proportionately large orbits and interpterygoid vacuities and a well-developed otic notch. Ruta & Bolt (2006) listed an extensive number of features that contribute to a unique combination of features, such as a frontal entering the orbit; orbits positioned at the approximate midlength of the skull; the absence of lateral line grooves; and parasphenoid denticles restricted to the region anterior to the basipterygoid processes. These were based on autapomorphies identified from their phylogenetic analysis, and the more recent diagnosis listed by Schoch & Milner (2014) only lists seven features, some shared with Ruta & Bolt and others new (e.g., humerus with supinator process). [3]
As originally interpreted by Carlson (1987), Perryella shared features with both trimerorhachid dvinosaurs and with dissorophoids based on select comparisons. For example, it shares a medial process of the quadratojugal that participates in the jaw articulation with Micromelerpeton, but this process does not wrap around a dorsal process of the quadrate as in many dissorophoids. A large exposure of the palatine bone on the skull roof (typically only exposed on the palate), termed a 'lateral exposure of the palatine' (LEP) is also common to dissorophoids and is found in Perryella, but it also occurs in some dvinosaurs like Acroplous and Isodectes. Carlson also cited proportions of the orbits, otic notches, and interpterygoid vacuities; the presence of denticles on the parasphenoid; the absence of an intertemporal; the presence of a double occipital condyle; and a retroarticular process on the lower jaw as evidence of dissorophoid affinities, although as he noted, these are commonly shared with other "advanced" temnospondyls and are perhaps better viewed as evidence against dvinosaur affinities. Carlson's reticence to place it within Dissorophoidea stemmed from the anatomy of the otic notch, as well as the separation between the lacrimal and the orbit and an anteriorly extensive jugal. [1] Carlson (1987) originally did not place it within a particular family or superfamily as a result.
Other workers more confidently placed Perryella as a dissorophoid. [4] In 2006, a phylogenetic analysis of Perryella as part of a larger redescription placed it within Dvinosauria as an intermediate form between trimerorhachids and other dvinosaurs. This analysis included stem tetrapods and Paleozoic temnospondyls and recovered dissorophoids and dvinosaurs as sister groups. Below is a portion of their phylogenetic topology:
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Schoch & Milner (2014) placed Perryella as an indeterminate dissorophoid, arguing that it shared certain features such as the LEP with 'amphibamids' (now amphibamiforms) and micromelerpetids; this classification was based on qualitative comparisons, as they did not perform a phylogenetic analysis. Schoch (2018) included Perryella in an analysis and recovered it as a "stem dissorophoid" (closely related to Dissorophoidea). Below is Schoch's phylogeny: [5]
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Cacops, is a genus of dissorophid temnospondyls from the Kungurian stage of the early Permian of the United States. Cacops is one of the few olsoniforms whose ontogeny is known. Cacops fossils were almost exclusively known from the Cacops Bone Bed of the Lower Permian Arroyo Formation of Texas for much of the 20th century. New material collected from the Dolese Brothers Quarry, near Richards Spur, Oklahoma in the past few decades has been recovered, painting a clearer picture of what the animal looked and acted like.
Dissorophidae is an extinct family of medium-sized, temnospondyl amphibians that flourished during the late Carboniferous and early Permian periods. The clade is known almost exclusively from North America.
Dissorophoidea is a clade of medium-sized, temnospondyl amphibians that appeared during the Moscovian in Euramerica, and continued through to the Late Permian and the Early Triassic of Gondwana. They are distinguished by various details of the skull, and many species seem to have been well adapted for life on land.
Temnospondyli is a diverse order of small to giant tetrapods—often considered primitive amphibians—that flourished worldwide during the Carboniferous, Permian, and Triassic periods. A few species continued into the Jurassic and Cretaceous periods. Fossils have been found on every continent. 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 considered amphibians, many had characteristics, such as scales and armour-like bony plates, that distinguish them from modern amphibians (lissamphibians).
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.
Laidleria is an extinct genus of temnospondyl that likely lived between the Early to Middle Triassic, though its exact stratigraphic range is less certain. Laidleria has been found in the Karoo Basin in South Africa, in Cynognathus Zone A or B. The genus is represented by only one species, L. gracilis, though the family Laidleriidae does include other genera, such as Uruyiella, sister taxon to Laidleria, which was discovered and classified in 2007.
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.
Konzhukovia is an amphibian genus that belongs to an extinct group of temnospondyls, the largest clade of basal tetrapods including about 198 genera, 292 species, and more than half of which were alive during the early Mesozoic period. The animal was a predator that lived about 260 million years ago, and could get up to about three meters in length. Specifically, Konzukovia lived during the Permian, between 252 and 270 million years ago according to the type of rock the fossil was found in. There are three species within this genus, K. vetusta, K. tarda, and K. sangabrielensis, the first two originating from Russia while the latest originating from Southern Brazil. The discovery of this specimen in Southern Brazil provided more evidence to support the idea that during this animals existence, there was a “biological corridor” because of the supercontinent Pangea, allowing these species to be found so far apart from each other. Konzhukovia belongs to the family Archegosauridae, a family consisted of large temnospondyls that most likely compare to modern day crocodiles. Since the discovery of the latest species, K. sangabrielensis, Pacheco proposes that there must be the creation of a new family, Konzhokoviidae, a monophyletic group in a sister-group relationship with Stereospondlyi in order to accommodate the three species. Konzhukovia skulls usually exhibit typical rhinesuchid features including an overall parabolic shape, small orbits located more posteriorly, and the pterygoids do not reach the vomer. These animals were long-snouted amphibians that had clear adaptations made for fish catching, as well as exemplifying aquatic features.
Rhinesuchidae is a family of tetrapods that lived primarily in the Permian period. They belonged to the broad group Temnospondyli, a successful and diverse collection of semiaquatic tetrapods which modern amphibians are probably descended from. Rhinesuchids can be differentiated from other temnospondyls by details of their skulls, most notably the interior structure of their otic notches at the back of the skull. They were among the earliest-diverging members of the Stereospondyli, a subgroup of temnospondyls with flat heads and aquatic habits. Although more advanced stereospondyls evolved to reach worldwide distribution in the Triassic period, rhinesuchids primarily lived in the high-latitude environments of Gondwana during the Guadalupian and Lopingian epochs of the Permian. The taxonomy of this family has been convoluted, with more than twenty species having been named in the past; a 2017 review recognized only eight of them to be valid. While several purported members of this group have been reported to have lived in the Triassic period, most are either dubious or do not belong to the group. However, at least one valid genus of rhinesuchid is known from the early Triassic, a small member known as Broomistega. The most recent formal definition of Rhinesuchidae, advocated by Mariscano et al. (2017) is that of a stem-based clade containing all taxa more closely related to Rhinesuchus whaitsi than to Lydekkerina huxleyi or Peltobatrachus pustulatus. A similar alternate definition is that Rhinesuchidae is a stem-based clade containing all taxa more closely related to Uranocentrodon senekalensis than to Lydekkerina huxleyi, Trematosaurus brauni, or Mastodonsaurus giganteus.
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.
Anconastes is an extinct genus of dissorophoid temnospondyl within the family Trematopidae. It is known from two specimens from the Late Carboniferous Cutler Formation of north-central New Mexico in the southwestern United States. The genus name derives from two Greek roots, ankos and nastes ("inhabitant"), which refers to the type locality of El Cobre Canyon where the specimens were found. The specific name is derived from the Latin word vesperus ("western"). The more complete specimen, the holotype, is a partial skull with articulated mandibles and a substantial amount of the postcranial skeleton. The less complete specimen, the paratype, consists only of the right margin of the skull with an articulated mandible.
Actiobates is an extinct genus of trematopid temnospondyl that lived during the Late Carboniferous. It is known from the Garnett Quarry in Kansas.
Ecolsonia is an extinct genus of trematopid temnospondyl. Its phylogenetic position within Olsoniformes has been historically debated, but it is presently considered to be a trematopid.
Doleserpeton is an extinct, monospecific genus of dissorophoidean temnospondyl within the family Amphibamidae that lived during the Upper Permian, 285 million years ago. Doleserpeton is represented by a single species, Doleserpeton annectens, which was first described by John R. Bolt in 1969. Fossil evidence of Doleserpeton was recovered from the Dolese Brothers Limestone Quarry in Fort Sill, Oklahoma. The genus name Doleserpeton is derived from the initial discovery site in Dolese quarry of Oklahoma and the Greek root "herp-", meaning "low or close to the ground". This transitional fossil displays primitive traits of amphibians that allowed for successful adaptation from aquatic to terrestrial environments. In many phylogenies, lissamphibians appear as the sister group of Doleserpeton.
Dissorophus (DI-soh-ROH-fus) is an extinct genus of temnospondyl amphibian that lived during the Early Permian Period about 273 million years ago. Its fossils have been found in Texas and in Oklahoma in North America. Its heavy armor and robust build indicate Dissorophus was active on land, similar to other members of the clade Dissorophidae that are known from the Late Carboniferous to the Early Permian periods. Dissorphus is distinguished by its small body size, disproportionately large head and short trunk.
Iratusaurus is an extinct genus of dissorophoid temnospondyl within the family Dissorophidae. It was described by Gubin (1980) on the basis of a fragmentary posterior skull. It is estimated to have been comparably large to Kamacops, another Russian dissorophid, but little more can be said about it, and it is rarely mentioned in comparative descriptions and has never been tested in a phylogenetic analysis. Distinguishing features include a large, triangular otic notch and a median crest on the postparietals.
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.
Tersomius is an extinct genus of dissorophoid temnospondyl within the family Micropholidae. It is known from the early Permian of North America.
Amphibamiformes is an unranked clade with Dissorophoidea created by Schoch (2018). It encompasses all of the taxa traditionally considered to be "amphibamids", branchiosaurids, and hypothetically lissamphibians under the traditional temnospondyl hypothesis of lissamphibian origins. These taxa are typically small-bodied dissorophoids and form the sister group to Olsoniformes, which comprises dissorophids and trematopids.
