| Parioxys Temporal range: Early Permian | |
|---|---|
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Amphibia |
| Order: | † Temnospondyli |
| Family: | † Parioxyidae Moustafa, 1955 |
| Genus: | † Parioxys Cope, 1878 |
| Species | |
Parioxys is an extinct genus of temnospondyl amphibian from the Early Permian of Texas.
The type species, Parioxys ferricolus, was named in 1878 by American paleontologist Edward Drinker Cope based on two badly preserved skulls were collected from the early Permian Texas red beds. [1] Both skulls were collected in the same year from Mount Barry, a site in the Petrolia Formation [2] (formerly "Belle Plains Formation") of Wichita County, Texas. They are now stored in the American Museum of Natural History (AMNH). One of the P. ferricolus skulls, AMNH 4309, has frequently been conflated with AMNH 4310, a slightly larger Eryops skull ("Eryops anatinus") collected from Wichita County in 1880. The other P. ferricolus skull is designated AMNH 2445. [3]
Over the course of several papers in 1952 and 1955, Egyptian paleontologist Youssef S. Moustafa redescribed Cope's skulls along with new material from additional localities in Texas. [3] [4] [5] [6] AMNH 4309 was designated as the holotype of P. ferricolus. [3] One of the new specimens, MCZ 1162, was collected from Baylor County in 1934. MCZ 1162 consists of a large block containing fossils from at least eight individuals, including four skulls and numerous postcranial bones. [4] [5]
Further preparation of P. ferricolus skull material allowed a redescription by Schoch & Sues (2022). [2] Moustafa described a second species, P. romeri, on the basis of an isolated humerus, but this was regarded as being indeterminate. [2] Another proposed species, Parioxys bolli, was named and described by Canadian paleontologist Robert Carroll in 1964. [7] This species is only known from postcranial fragments from the Archer City Formation of Archer County. [2] Some sources have suggested that P. bolli is an unrelated species of temnospondyl, possibly a trematopid close to Ecolsonia cutlerensis . [8]
Parioxys was historically considered to be closely related to eryopoids, more specifically the well-known Eryops megalocephalus. Eryops fossils have been collected from the same locality as the type material of P. ferricolus. Subsequent to his original description, Cope listed P. ferricolus as a species of Eryops, [9] [10] possibly because he considered it to be a juvenile specimen of Eryops. [11]
In 1911, Parioxys was revived as a distinct genus [11] [12] with a suggestion that the original specimens described by Cope might have been inadvertently described as other taxa by later authors. [13] Its affinities continued to be debated, with some suggestions that it might instead belong to the Trematopidae. [14] [15] Moustafa (1955) placed Parioxys in its own family and suggested that it was related to the Dissorophidae. [5] Schoch & Milner (2014) placed Parioxys within Dissorophidae based on personal observations of further preparation of historic material, although at the time this suggestion was not tested via a phylogenetic analysis, due to the poor quality of much of the material. [16]
The revision by Schoch & Sues (2022) finally tested the position of P. ferricolus in a dissorophoid-oriented phylogenetic matrix. They recovered it as a eucacopine dissorophid, most closely related to Kamacops from the Middle Permian of Russia. They list the following features as features shared between this species and Kamacops and not with Cacops: (1) smaller interpterygoid vacuities, resulting from the medial expansion of palatine and pterygoid (condition more extreme in K. acervalis); (2) the enlarged vomer with the posteriorly elongated, slit-like choana; and (3) the absence of an internarial fenestra.
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 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.
Zatracheidae is a family of Late Carboniferous and Early Permian temnospondyl amphibians known from North America and Europe. Zatracheidids are distinguished by lateral (sideways) bony protuberances of the quadratojugal bone of the skull, and a large opening in the snout called the internarial fontanelle that is bordered by enlarged premaxillae. The skull is flattened, with small orbits or eye sockets set far back. The opening in the snout may have housed a gland for producing a sticky substance so that prey would adhere to the tongue. If so, this indicates that these animals spent a large part of their time on land.
Platyhystrix is an extinct temnospondyl amphibian with a distinctive sail along its back, similar to the unrelated synapsids, Dimetrodon and Edaphosaurus. It lived during the boundary between the latest Carboniferous and earliest Permian periods throughout what is now known as the Four Corners, Texas, and Kansas about 300 million years ago.
Sclerocephalus is an extinct genus of temnospondyl amphibian from the lowermost Permian of Germany and Czech Republic with four valid species, including the type species S. haeuseri. It is one of the most completely preserved and most abundant Palaeozoic tetrapods. Sclerocephalus was once thought to be closely related to eryopoid temnospondyls, but it is now thought to be more closely related to archegosauroids. It is the only genus in the family Sclerocephalidae.
Zatrachys is an extinct genus of large and flat-headed zatracheidid temnospondyl from the early Permian of North America.
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.
Broiliellus is an extinct genus of dissorophoid temnospondyl within the family Dissorophidae. Broiliellus is most closely related to the genus Dissorophus, and both have been placed in the subfamily Dissorophinae. Broiliellus is known from five species from the Early Permian: the type species is Broiliellus texensis, and the other species are Broiliellus brevis,Broiliellus olsoni, Broiliellus arroyoensis, and Broiliellus reiszi. An additional species, Broiliellus novomexicanus, which was originally named Aspidosaurus novomexicanus, is now thought to fall outside the genus as a member of the subfamily Eucacopinae.
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.
Pariotichus is an extinct genus of gymnarthrid microsaurs 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.
Micropholis is an extinct genus of dissorophoid temnospondyl. Fossils have been found from the Lystrosaurus Assemblage Zone of the Karoo Basin in South Africa and are dated to the Induan. Fossils have also been found from the lower Fremouw of Antarctica.Micropholis is the only post-Permian dissorophoid and the only dissorophoid in what is presently the southern hemisphere and what would have been termed Gondwana during the amalgamation of Pangea.
The Amphibamidae are an ancient family of dissorophoid temnospondyls known from Late Carboniferous-Early Permian strata in the United States.
Perryella is an extinct genus of dvinosaurian(?) temnospondyl from the Permian of Oklahoma.
Eucacopinae is an extinct clade of dissorophid temnospondyls. Eucacopines differ from the other main group of dissorophids, the Dissorophinae, in having more lightly built skeletons and more knobby skulls. The subfamily was originally named Cacopinae, but since the name was already established for a group of living microhylid frogs in 1931, the name was changed to Eucacopinae in 2013. Eucacopinae is a stem-based taxon defined as the most inclusive clade containing the species Cacops apsidephorus but not Dissorophus multicinctus, which belongs to Dissorophinae. According to the most recent phylogenetic analyses of Dissorophidae, Eucacopinae includes the basal ("primitive") species Conjunctio multidens and Scapanops neglecta from the southwestern United States and a more derived ("advanced") group including several species of Cacops and the Russian genera Kamacops and Zygosaurus. Derived eucacopines have two rows of bony plates called osteoderms running down their backs, while the more basal eucacopines have only a single row. Dissorophines also have a double row of osteoderms but probably evolved them independently because the most recent common ancestor of the two groups had a single row of osteoderms.
Reiszerpeton is an extinct genus of dissorophid temnospondyl known from the Early Permian Archer City Formation of Texas. It is known solely from the holotype, MCZ 1911, a complete skull. This specimen was originally referred to the amphibamiform Tersomius texensis. A reappraisal of the holotype of T. texensis and a number of other referred specimens by Maddin et al. (2013) noted a number of differences from both T. texensis and amphibamiforms more broadly that suggested affinities with the Dissorophidae. This was confirmed by a phylogenetic analysis, which placed it as the sister taxon to the Eucacopinae. Reiszerpeton is known only from the type species, R. renascentis, which was named for Canadian paleontologist Robert Reisz. The species name refers to the recognition of Reisz as a "renaissance paleontologist." It is differentiated from other dissorophids by its small size, small and more numerous maxillary teeth, smooth cranial ornamentation, and greater distance between the orbit and the otic notch.
Nanobamus is an extinct genus of amphibamiform temnospondyl amphibian. The type species is Nanobamus macrorhinus. The type specimen is UCLAVP 3686, a skull recovered from the Lower Permian Arroyo Formation.
