Cisuralian genus extinctions

Dimetrodon ( or ; ) is an extinct genus of sphenacodontid synapsid that lived during the Cisuralian (Early Permian) epoch of the Permian period, around 295–272 million years ago. With most species measuring long and weighing , the most prominent feature of Dimetrodon is the large neural spine sail on its back formed by elongated spines extending from the vertebrae. It was an obligate quadruped (it could walk only on four legs) and had a tall, curved skull with large teeth of different sizes set along the jaws. Most fossils have been found in the Southwestern United States, the majority of

Calamites is a genus of extinct arborescent (tree-like) horsetails to which the modern horsetails (genus Equisetum) are closely related. Unlike their herbaceous modern cousins, these plants were medium-sized trees, growing to heights of . They were components of the understories of coal swamps of the Carboniferous Period (around ).

Edaphosaurus (, meaning "pavement lizard" for dense clusters of its teeth) is a genus of extinct edaphosaurid synapsids that lived in what is now North America and Europe around 303.4 to 272.5 million years ago, during the Late Carboniferous to Early Permian. The American paleontologist Edward Drinker Cope first described Edaphosaurus in 1882, naming it for the "dental pavement" on both the upper and lower jaws, from the Greek ' ("ground"; also "pavement") and (') ("lizard").

Sphenacodon (meaning "wedge point tooth") is an extinct genus of synapsid that lived from about 300 to about 280 million years ago (Ma) during the Late Carboniferous and Early Permian periods. Like the closely related Dimetrodon, Sphenacodon was a carnivorous member of the Eupelycosauria family Sphenacodontidae. However, Sphenacodon had a low crest along its back, formed from blade-like bones on its vertebrae (neural spines) instead of the tall dorsal sail found in Dimetrodon. Fossils of Sphenacodon are known from New Mexico and the Utah–Arizona border region in North America.

Glossopteris (etymology: from Ancient Greek γλῶσσα, glôssa 'tongue' + πτερίς, pterís 'fern') is the largest and best-known genus of the extinct Permian order of seed plants known as Glossopteridales (also known as Arberiales, Ottokariales, or Dictyopteridiales). The name Glossopteris refers only to leaves, within the framework of form genera used in paleobotany, used for leaves of plants belonging to the glossopterid family Dictyopteridiaceae.

Ophiacodon (meaning "snake tooth") is an extinct genus of synapsid belonging to the family Ophiacodontidae that lived from the Late Carboniferous to the Early Permian in North America and Europe. The genus was named along with its type species O. mirus by paleontologist Othniel Charles Marsh in 1878 and currently includes five other species. As an ophiacodontid, Ophiacodon is one of the most basal synapsids and is close to the evolutionary line leading to mammals.

Eryops (; from Greek , , 'drawn-out' + , , 'face', because most of its skull was in front of its eyes) is a genus of extinct, amphibious temnospondyls. It contains the type species '''', the fossils of which are found mainly in early Permian deposits of the Texas Red Beds, and Eryops grandis from New Mexico. Fossils have also been found in late Carboniferous rocks from New Mexico and early Permian deposits of Oklahoma, Utah, the Pittsburgh tri-state region, and Prince Edward Island. Several complete skeletons of Eryops'' have been found in lower Permian rocks, but skull bones and teeth are its

Secodontosaurus (meaning "cutting-tooth lizard") is an extinct genus of "pelycosaur" synapsids that lived from between about 285 to 272 million years ago during the Early Permian. Like the well known Dimetrodon, Secodontosaurus is a carnivorous member of the Eupelycosauria family Sphenacodontidae and has a similar tall dorsal sail. However, its skull is long, low, and narrow, with slender jaws that have teeth that are very similar in size and shape—unlike the shorter, deep skull of Dimetrodon ("two-measure tooth"), which has large, prominent canine-like teeth in front and smaller slicing teeth

Limnoscelis (/limˈnäsələ̇s/, meaning "marsh footed") is an extinct genus of large diadectomorph tetrapods from the Late Carboniferous to early Permian of western North America. It includes two species: the type species Limnoscelis paludis from New Mexico, and Limnoscelis dynatis from Colorado, both of which are thought to have lived concurrently. No specimens of Limnoscelis are known from outside of North America. Limnoscelis was carnivorous, and likely semiaquatic, though it may have spent a significant portion of its life on land. Limnoscelis had a combination of derived amphibian and primit

Varanops is an extinct genus of Early Permian varanopid known from Texas and Oklahoma of the United States. It was first named by Samuel Wendell Williston in 1911 as a second species of Varanosaurus, Varanosaurus brevirostris. In 1914, Samuel W. Williston reassigned it to its own genus and the type species is Varanops brevirostris. thumb|Reconstruction of Varanops brevirostris

Varanodon is an extinct genus of amniotes from the family Varanopidae. It has been found in the Chickasha Formation of Oklahoma, which dates to the Roadian stage of the Middle Permian. The largest varanopid known at the time of its description, with a skull length of , it was closely related to and lived alongside its much larger relative Watongia. The two may represent growth stages of a single animal.

Aerosaurus (meaning "copper lizard") is an extinct genus within Varanopidae, a family of non-mammalian synapsids. It lived between 252-299 million years ago during the Early Permian in North America. The name comes from Latin aes (aeris) (combining stem: aer-) “copper” and Greek sauros “lizard,” for El Cobre Canyon (from Spanish cobre “copper”) in northern New Mexico, where the type fossil was found and the site of former copper mines. Aerosaurus was a small to medium-bodied carnivorous synapsid characterized by its recurved teeth, triangular lateral temporal fenestra, and extended teeth row.

Mycterosaurus (Greek as mykter/mykteros meaning nose/snout, sauros meaning "lizard") is an extinct genus of amniotes belonging to the family Varanopidae. It is classified in the varanopid subfamily Mycterosaurinae. Mycterosaurus is the most primitive member of its family, existing from 290.1 to 272.5 MYA, known to Texas and Oklahoma. It lacks some features that its advanced relatives have.

Glaucosaurus is an extinct genus of edaphosaurid synapsid from the Early Permian of Texas. The type species, G. megalops, was named in 1915.

Oedaleops is an extinct genus of caseasaur synapsids from the Early Permian of the Southwestern United States. Fossils have been found in the Cutler Formation in New Mexico, which dates back to the Wolfcampian stage of the Early Permian. All remains belong to the single known species Oedaleops campi. Oedaleops was closely related to Eothyris, and both are part of the family Eothyrididae. Like Eothyris, it was probably an insectivore.

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.

Apsisaurus is an extinct genus of Early Permian varanopid synapsids known from Texas of the United States. It was first named by Michel Laurin in 1991 and the type species is Apsisaurus witteri. Apsisaurus witteri is known from the holotype MCZ 1474, a three-dimensionally preserved partial skeleton including an incomplete skull and mandibles. The skull roof of Archeria is also articulated to the postcranial skeleton. It was collected in the Archer City Bonebed 1 site, from the Archer City Formation of the Wichita Group, dating to the Early Permian epoch. Apsisaurus was formerly assigned a

genus of synapsid

Aspidosaurus is an extinct genus of dissorophoid temnospondyl within the family Dissorophidae.

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.

Lupeosaurus is an extinct genus of pelycosaurian synapsids, assigned to the family Edaphosauridae. Lupeosaurus was about long and weighed around .

Baldwinonus is an extinct genus of basal synapsids from the Early Permian. The type species is Baldwinonus trux, named in 1940 from the Cutler Formation of New Mexico. A second species, Baldwinonus dunkardensis, was named in 1952 from Ohio. Baldwinonus was first classified in the family Eothyrididae, but the group has since been recognized as a wastebasket taxon for many early synapsids. More recently, Baldwinonus has been placed in the family Ophiacodontidae. Its phylogenetic relationship to other early synapsids remains poorly understood because it is only known from a few fragments of bone.

Aeduella is an extinct genus of freshwater ray-finned fish that lived during the Gzhelian (Late Pennsylvanian, Carboniferous ) and Asselian-Sakmarian (Cisuralian/early Permian epoch) ages in what is now France (Auvergne, Burgundy and Aveyron), Germany (Baden-Württemberg, Rhineland-Palatine, Saarland), Switzerland (Basel-Landschaft, Zürich) and the Czech Republic.

Ruthiromia is an extinct genus of varanopid synapsids from the Early Permian of the United States.

Elonichthys is an extinct genus of prehistoric freshwater ray-finned fish known from the late Paleozoic. The genus sensu stricto contains three species known from the latest Carboniferous to the earliest Permian of freshwater ecosystems of Europe, but as a former wastebasket taxon, it contains many more dubiously-classified species from the Carboniferous and Permian of Europe, Greenland, South Africa, and North America.

Gorgodon is an extinct genus of basal synapsids. The genus is monotypic, known only from the type species Gorgodon minutus from the Early Permian of the southwestern United States. The only known remains of Gorgodon are two fossils consisting of fragments of the skull. Gorgodon was described and named by paleontologist Everett C. Olson in 1962 from the San Angelo Formation in Knox County, Texas. Based on what is known of Gorgodon—the squamosal, quadrate, and pterygoid bones of the back of the skull, the maxilla and premaxilla bones that make up the front of the skull, and several teeth—Gorgodo