"Labyrinthodontia" is an informal grouping of extinct predatory amphibians which were major components of ecosystems in the late Paleozoic and early Mesozoic eras. Traditionally considered a subclass of the class Amphibia, modern classification systems recognize that labyrinthodonts are not a formal natural group (clade) exclusive of other tetrapods. Instead, they consistute an evolutionary grade, ancestral to living tetrapods such as lissamphibians and amniotes. "Labyrinthodont"-grade vertebrates evolved from lobe-finned fishes in the Devonian, though a formal boundary between fish and amphibian is difficult to define at this point in time.
Eureptilia is one of the two major subgroups of the clade Sauropsida, the other one being Parareptilia. Eureptilia includes Diapsida, as well as a number of primitive Permo-Carboniferous forms previously classified under Anapsida, in the old order "Cotylosauria".
Lethiscus is the earliest known representative of the Aistopoda, a group of very specialised snake-like tetrapodomorphs known from the early Carboniferous (Mississippian).
Crassigyrinus is an extinct genus of carnivorous stem tetrapod from the Early Carboniferous Limestone Coal Group of Scotland and possibly Greer, West Virginia.
Eucritta is an extinct genus of stem-tetrapod from the Viséan epoch in the Carboniferous period of Scotland. The name of the type and only species, E. melanolimnetes is a homage to the 1954 horror film Creature from the Black Lagoon.
Ophiderpeton is an extinct genus of aistopod tetrapodomorphs from the early Carboniferous to the early Permian. Remains of this genus are widespread and were found in Ohio, United States, Ireland, and the Czech Republic.
Embolomeri is an order of tetrapods or stem-tetrapods, possibly members of Reptiliomorpha. Embolomeres first evolved in the Early Carboniferous (Mississippian) Period and were the largest and most successful predatory tetrapods of the Late Carboniferous (Pennsylvanian) Period. They were specialized semiaquatic predators with long bodies for eel-like undulatory swimming. Embolomeres are characterized by their vertebral centra, which are formed by two cylindrical segments, the pleurocentrum at the rear and intercentrum at the front. These segments are equal in size. Most other tetrapods have pleurocentra and intercentra which are drastically different in size and shape.
Anthracosaurus is an extinct genus of embolomere, a possible distant relative of reptiles that lived during the Late Carboniferous in what is now Scotland, England, and Ohio. It was a large, aquatic eel-like predator. It has a robust skull about 40 centimetres (1.3 ft) in length with large teeth in the jaws and on the roof of the mouth. Anthracosaurus probably inhabited swamps, rivers and lakes. Its name is Greek for "coal lizard".
Pederpes is an extinct genus of early Carboniferous tetrapod, dating from 348 to 347.6 Ma in the Tournaisian age. Pederpes contains one species, P. finneyae, 1 m long.
Edops is an extinct genus of temnospondyl amphibian from the Late Carboniferous - Early Permian periods. Unlike more advanced temnospondyls of the time, such as Eryops, Edops exhibited an archaic pattern of palatal bones, and still possessed various additional bones at the back of the skull. Edopoids also had particularly big premaxillae and proportionally small external nostrils. Within the clade, the most basal member seems to be Edops from the Early Permian Archer City Formation of the US, a broad-skulled animal with large palatal teeth.
Micromelerpetontidae is an extinct family of dissorophoid temnospondyls that lived from the Late Carboniferous to the Early Permian in what is now Europe, with one Carboniferous species also known from North Africa. They were biologically similar to the related branchiosaurids, but proportionally akin to the unrelated microsaurs.
Brachydectes is an extinct genus of lysorophian tetrapods that lived from the Late Carboniferous to the Early Permian. It had a very small head and long body, B. elongatus had 1–2 centimetres (0.39–0.79 in) long skull and pre-sacral length up to 150 centimetres (59 in), while B. newberryi, which have proportionally larger skull than B. elongatus, for specimen with 7.6 millimetres (0.30 in) skull roof had estimated total length of 11 centimetres (4.3 in), while the largest skull exceeds 3 centimetres (1.2 in).
Spathicephalus is an extinct genus of stem tetrapods that lived during the middle of the Carboniferous Period. The genus includes two species: the type species S. mirus from Scotland, which is known from two mostly complete skulls and other cranial material, and the species S. pereger from Nova Scotia, which is known from a single fragment of the skull table. Based on the S. mirus material, the appearance of Spathicephalus is unlike that of any other early tetrapod, with a flattened, square-shaped skull and jaws lined with hundreds of very small chisel-like teeth. However, Spathicephalus shares several anatomical features with a family of stem tetrapods called Baphetidae, leading most paleontologists who have studied the genus to place it within a larger group called Baphetoidea, often as part of its own monotypic family Spathicephalidae. Spathicephalus is thought to have fed on aquatic invertebrates through a combination of suction feeding and filter feeding.
Limnarchia is a clade of temnospondyls. It includes the mostly Carboniferous-Permian age Dvinosauria and the mostly Permian-Triassic age Stereospondylomorpha. The clade was named in a 2000 phylogenetic analysis of stereospondyls and their relatives. Limnarchia means "lake rulers" in Greek, in reference to their aquatic lifestyles and long existence over a span of approximately 200 million years from the Late Carboniferous to the Early Cretaceous. In phylogenetic terms, Limnarchia is a stem-based taxon including all temnospondyls more closely related to Parotosuchus than to Eryops. It is the sister group of the clade Euskelia, which is all temnospondyls more closely related to Eryops than to Parotosuchus. Limnarchians represent an evolutionary radiation of temnospondyls into aquatic environments, while euskelians represent a radiation into terrestrial environments. While many euskelians were adapted to life on land with strong limbs and bony scutes, most limnarchians were better adapted for the water with poorly developed limbs and lateral line sensory systems in their skulls.
Megamolgophis is an extinct genus of eel-like tetrapod, possibly belonging to the group Lysorophia. Fossils from this genus have been found in the Allegheny mountains of the eastern United States. The genus is endemic to geological formations of this area, such as the Greene and Washington formations of the Early Permian Dunkard Group, as well as the Pennsylvanian Conemaugh Group.
Tuditanidae is an extinct family of microsaurian tetrapods. Fossils have been found from Nova Scotia, Ohio, and the Czech Republic and are Late Carboniferous in age.
Kyrinion is an extinct genus of baphetid tetrapodomorph from the Late Carboniferous of England. It is known from a skull that was found in Tyne and Wear county dating back to the Westphalian stage. Along with the skull is part of the lower jaw, an arch of the atlas bone and a rib possibly belonging to a cervical (neck) vertebra. The type species K. martilli was named from this material in 2003.
Eldeceeon is an extinct genus of reptiliomorph from the Mississippian of Scotland. It is known from two fossil specimens found within the Viséan-age East Kirkton Quarry in West Lothian. The type and only species, E. rolfei, was named in 1994. Eldeceeon is thought to be closely related to embolomeres, but it has several distinguishing features including long limbs and a short trunk. Initially known from two crushed partial skeletons, additional specimens have been reported by Ruta & Clack (2006). Eldeceeon was redescribed by Ruta, Clack, & Smithson (2020). The redescription supported affinities with Silvanerpeton, reconstructed a skull with larger eyes and a shorter snout, and emphasized potential correlations for an enlarge puboischiofemoralis internus 2 muscle.
Eusauropleura is an extinct genus of gephyrostegid reptiliomorph from the Pennsylvanian of Linton, Ohio. The type species and only species, Eusauropleura digitata, was first described by American paleontologist Edward Drinker Cope in 1868 as Sauropleura digitata. In 1930, paleontologist Alfred Romer placed the species in the new genus Eusauropleura. Romer considered S. digitata to be a reptile or a more primitive relative of reptiles, making it only distantly related to Sauropleura, which is a lepospondyl amphibian.
Edopoidea is a clade of primitive temnospondyl amphibians including the genus Edops and the family Cochleosauridae. Edopoids are known from the Late Carboniferous and Early Permian of North America and Europe, and the Late Permian of Africa. They are among the most basal temnospondyls, and possess a number of primitive features that were lost in later members of the group.
