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.
Zygosaurus is an extinct genus of dissorophid temnospondyl from the Middle-Late Permian of Russia. It was described in 1848 by Eduard Eichwald, making it the first dissorophid to be described and is known from a single species, Zygosaurus lucius. The location of the holotype, and only known specimen, is unknown, and although casts are reposited in several institutions, little is known about this taxon beyond qualitative aspects of the skull. The skull was estimated to be around 20 cm in length, making it one of the largest dissorophids, being only slightly smaller than Kamacops.
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.
Aspidosaurus is an extinct genus of dissorophoid temnospondyl within the family Dissorophidae.
Actiobates is an extinct genus of trematopid temnospondyl that lived during the Late Carboniferous. It is known from the Garnett Quarry in Kansas.
Conjunctio is an extinct genus of dissorophid temnospondyl amphibian from the early Permian of New Mexico. The type species, Conjunctio multidens, was named by paleontologist Robert L. Carroll in 1964.
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.
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.
Ostodolepis is an extinct genus of microsaur within the family Ostodolepidae. It is known from the Arroyo Formation in Texas.
Rileymillerus is an extinct genus of temnospondyl amphibian from the Late Triassic Post Quarry in the Dockum Group of Texas that was described by John Bolt and Sankar Chatterjee in 2000. The holotype, a nearly complete skull with articulated jaws, is housed at the Museum of Texas Tech University. The genus is named for Riley Miller, who allowed Chatterjee to work on the Post Quarry, and the species is named for the paleontologist John Cosgriff.
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.
Olsoniformes is a clade of dissorophoid temnospondyls. It includes the families Dissorophidae and Trematopidae. Most members of the clade were highly adapted to a terrestrial lifestyle. The clade was named in 2008 and is defined as the least inclusive clade containing Dissorophus multicinctus and Acheloma cumminsi but not Amphibamus grandiceps, Micromelerpeton credneri, and Apateon pedestris. Olsoniforms share various features such as a stout and low ilium and a thin cultriform process.
Perryella is an extinct genus of dvinosaurian(?) temnospondyl from the Permian of Oklahoma.
Parioxys is an extinct genus of temnospondyl amphibian from the Early Permian of Texas.
Scapanops is an extinct genus of dissorophid temnospondyl amphibian known from the Early Permian Nocona Formation of north-central Texas, United States. It contains only the type species Scapanops neglecta, which was named by Rainer R. Schoch and Hans-Dieter Sues in 2013. Scapanops differs from other dissorophids in having a very small skull table, which means that its eye sockets are unusually close to the back of the skull. The eye sockets are also very large and spaced far apart. Scapanops was probably small-bodied with a proportionally large head and short trunk and tail. Like other dissorophids, it probably spent most of its life on land.
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.
The Waggoner Ranch Formation is a geologic formation in northern Texas. It preserves fossils dating back to the Artinskian to Kungurian stages of the Permian period.
