Admetophoneus

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Admetophoneus
Temporal range: Middle Permian
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Chordata
Clade: Therapsida
Suborder: Dinocephalia
Genus: Admetophoneus
Efremov, 1954
Species:
A. kargalensis
Binomial name
Admetophoneus kargalensis
Efremov, 1954

Admetophoneus is a dubious genus of non-mammalian synapsid from Russia. Its type and only species is Admetophoneus kargalensis.

Contents

History

Admetophoneus was named by the Russian paleontologist Ivan Efremov in 1954, based on some teeth, a fragmentary maxilla, and a humerus. [1] :260 It was originally classified as a member of Brithopodidae. [1] :235–236 Later, it was classified in Phthinosuchidae. [2] :984–985 Recent study, however, has shown that it is a member of Anteosauria, but lacks diagnostic features. [3] :287 It is essentially identical to the contemporaneous Titanophoneus , and could be synonymous with it, but its poor preservation means that it cannot be proven.

See also

Related Research Articles

Dinosaurus is an extinct genus of therapsid of controversial affinities. Its type and only species is Dinosaurus murchisonii. It is only known from a partial snout from the Permian of Russia. Its taxonomic history is intertwined with several other poorly-known Russian therapsids, particularly Rhopalodon, Brithopus, and Phthinosuchus.

Synapsid Clade of tetrapods

Synapsids are a group of animals that includes mammals and every animal more closely related to mammals than to the other members of the amniote clade, such as reptiles and birds. Unlike other amniotes, they have a temporal fenestra, an opening low in the skull roof behind each eye, leaving a bony arch beneath each; this accounts for their name. Primitive synapsids are usually called pelycosaurs or pelycosaur-grade synapsids. This informal term consists of all synapsids that are not therapsids, a monophyletic, more advanced, mammal-like group. The non-mammalian synapsids were described as mammal-like reptiles in classical systematics, but this misleading terminology is no longer in use as synapsids as a whole are no longer considered reptiles. They are now more correctly referred to as stem mammals or proto-mammals.

Therapsid Clade of synapsids

Therapsida is a major group of eupelycosaurian synapsids that includes mammals and their ancestors. Many of the traits today seen as unique to mammals had their origin within early therapsids, including limbs that were oriented more underneath the body, as opposed to the sprawling posture of many reptiles and salamanders. The earliest fossil attributed to Therapsida used to be Tetraceratops insignis from the Lower Permian. However, in 2020 a study concluded that Tetraceratops is not a true therapsid, but should be considered a member of the more ancient Sphenacodontia, from which the therapsids evolved.

Dinocephalia Extinct clade of mammals

Dinocephalia is a clade of large-bodied early therapsids that flourished for a brief time in the Middle Permian between 270 and 260 million years ago (Ma), but became extinct, leaving no descendants. Dinocephalians included herbivorous, carnivorous, and omnivorous forms. Many species had thickened skulls with many knobs and bony projections. Dinocephalians were the first non-mammalian therapsids to be scientifically described and their fossils are known from Russia, China, Brazil, South Africa, Zimbabwe, and Tanzania.

Biarmosuchia Extinct suborder of therapsids

Biarmosuchia is an extinct clade of non-mammalian synapsids from the Permian. Biarmosuchians are the most basal group of the therapsids. They were moderately-sized, lightly-built carnivores, intermediate in form between basal sphenacodont "pelycosaurs" and more advanced therapsids. Biarmosuchians were rare components of Permian ecosystems, and the majority of species belong to the clade Burnetiamorpha, which are characterized by elaborate cranial ornamentation.

<i>Titanophoneus</i> Extinct genus of therapsids

Titanophoneus is an extinct genus of carnivorous dinocephalian therapsid from the Middle Permian. It is classified within the family Anteosauridae. The type species is Titanophoneus potens. Remains of Titanophoneus have been found at Isheevo in Russia.

Anteosaur Extinct clade of therapsids

Anteosaurs are a group of large, primitive carnivorous dinocephalian therapsids with large canines and incisors and short limbs, that are known from the Middle Permian of South Africa, Russia, China, and Brazil. Some grew very large, with skulls 50–80 centimetres (20–31 in) long, and were the largest predators of their time. They died out at the end of the Middle Permian, possibly as a result of the extinction of the herbivorous Tapinocephalia on which they may have fed.

Caseasauria Extinct clade of synapsids

Caseasauria is one of the two main clades of early synapsids, the other being the Eupelycosauria. Caseasaurs are currently known only from the Late Carboniferous and the Permian, and include two superficially different families, the small insectivorous or carnivorous Eothyrididae, and the large, herbivorous, potentially aquatic Caseidae. These two groups share a number of specialised features associated with the morphology of the snout and external naris.

Therocephalia Extinct suborder of therapsids

Therocephalia is an extinct suborder of eutheriodont therapsids from the Permian and Triassic. The therocephalians ("beast-heads") are named after their large skulls, which, along with the structure of their teeth, suggest that they were carnivores. Like other non-mammalian synapsids, therocephalians were once described as "mammal-like reptiles". Therocephalia is the group most closely related to the cynodonts, which gave rise to the mammals. This relationship takes evidence in a variety of skeletal features. The phylogeny of therocephalians has been disputed, as the monophyly of the group and the relationships of its members are unclear.

Casea is an extinct genus of medium to large-bodied, herbivorous, pelycosaur synapsids from the late Carboniferous until the middle Permian. The name Casea references its appearance from the Caseasauria which developed new morphology of their external naris and snout. Casea were known to be about 1.2 meters long. It weighed between 150 kg to 200 kg. It was slightly smaller than the otherwise very similar Caseoides. Casea was one of the first amniote herbivores, sharing its world with animals such as Dimetrodon and Eryops. It was possibly also aquatic.

<i>Brithopus</i> Extinct genus of mammal ancestors

Brithopus is an extinct genus of dinocephalian therapsids. It contains a single species, Brithopus priscus, known from fragmentary remains found in the Copper Sandstones near Isheevo, Russia.

<i>Daptocephalus</i> Extinct genus of dicynodonts

Daptocephalus is an extinct genus of non-mammalian synapsid anomodont dicynodont, it which was found in Late Permian strata, in a biozone known precisely for the presence of fossils of this dicynodont, the Daptocephalus Zone, in the Karoo Basin in South Africa. An additional species, D. huenei, is known from the Usili Formation in Tanzania and was formerly assigned to the genus Dicynodon before a study in 2019 recognised that the type specimen belonged to Daptocephalus.

Elliotsmithia is a small varanopid synapsid found from the late Middle Permian of South Africa. It is the sole basal synapsid "pelycosaur" known from the supercontinent Gondwana and only two specimens have been yielded to date. Its species name longiceps is derived from Latin, meaning "long head". Both known Elliotsmithia fossils were recovered from Abrahamskraal Formation rocks—within the boundaries of the Tapinocephalus Assemblage Zone—of the lower Beaufort Group.

<i>Mesenosaurus</i> Extinct genus of synapsids

Mesenosaurus is an extinct genus of amniote. It belongs to the family Varanopidae. This genus includes two species: the type species Mesenosaurus romeri from the middle Permian Mezen River Basin of northern Russia, and Mesenosaurus efremovi from the early Permian (Artinskian) Richards Spur locality. M. romeri’s stratigraphic range is the middle to late Guadalupian while M. efremovi’s stratigraphic range is the Cisuralian.

Orthopus is an extinct genus of non-mammalian synapsids. It is based on a partial humerus that closely resembles Estemmenosuchus, in the limited comparisons possible.

Oromycter is an extinct genus of caseid synapsids from the Early Permian of Oklahoma. The sole and type species, Oromycter dolesorum, was named in 2005 by Robert R. Reisz.

<i>Niaftasuchus</i> Extinct genus of therapsids

Niaftasuchus is an extinct genus of therapsids. Its type and only named species is Niaftasuchus zekkeli.

<i>Smilesaurus</i> Extinct genus of therapsids

Smilesaurus is an extinct genus of gorgonopsian known from Africa. It lived during the Late Permian. It contains the single species S. ferox.

<i>Ulemica</i> Extinct genus of therapsids

Ulemica is an extinct genus of venjukoviid therapsids. It was a basal member of the suborder Anomodontia that existed during the Middle Permian in Russia. The type species, U. invisa, was assigned to the genus Venjukovia prior to being placed within its own genus in 1996. This small anomonodont is only known from a partial skull found in the Amanakskaya Formation.

Parasumina is an extinct genus of anomodont known from the late Capitanian age at the end of the middle Permian period of European Russia. The type and only species is Parasuminia ivakhnekoi. It was closely related to Suminia, another Russian anomodont, and was named for its resemblance. Little is known about Parasuminia as the only fossils are of fragmentary pieces of the skull and jaw, but the known remains suggest that its head and jaws were deeper and more robust than those of Suminia, and with shorter, stouter teeth. However, despite these differences they appear to have been similar animals with a similarly complex method of processing vegetation.

References

  1. 1 2 Efremov, I. A. (1954). Фауна наземных позвоночных в пермских медистых песчаниках западного Приуралья[The terrestrial vertebrate fauna from the Permian copper sandstones of the western Fore-Urals]. Trudy Paleontologicheskogo Instituta, Akademiya Nauk SSSR (in Russian). 54.
  2. Ivakhnenko, M. F. (2008). "Cranial morphology and evolution of Permian Dinomorpha (Eotherapsida) of Eastern Europe". Paleontological Journal. 42 (9). doi:10.1134/S0031030108090013.
  3. Kammerer, Christian F. (2011). "Systematics of the Anteosauria (Therapsida: Dinocephalia)". Journal of Systematic Palaeontology. 9 (2): 261–304. doi:10.1080/14772019.2010.492645.