Lepospondyli is a diverse taxon of early tetrapods. With the exception of one late-surviving lepospondyl from the Late Permian of Morocco, lepospondyls lived from the Early Carboniferous (Mississippian) to the Early Permian and were geographically restricted to what is now Europe and North America. Five major groups of lepospondyls are known: Adelospondyli; Aïstopoda; Lysorophia; Microsauria; and Nectridea. Lepospondyls have a diverse range of body forms and include species with newt-like, eel- or snake-like, and lizard-like forms. Various species were aquatic, semiaquatic, or terrestrial. None were large, and they are assumed to have lived in specialized ecological niches not taken by the more numerous temnospondyl amphibians that coexisted with them in the Paleozoic. Lepospondyli was named in 1888 by Karl Alfred von Zittel, who coined the name to include some tetrapods from the Paleozoic that shared some specific characteristics in the notochord and teeth. Lepospondyls have sometimes been considered to be either related or ancestral to modern amphibians or to Amniota. It has been suggested that the grouping is polyphyletic, with aïstopods being primitive stem-tetrapods, while recumbirostran microsaurs are primitive reptiles.
Stegops is an extinct genus of euskelian temnospondyl from the Late Carboniferous of the eastern United States. Fossils are known from the Pennsylvanian coal deposits of Linton, Ohio. It was once classified in the eryopoid family Zatrachydidae because it and other zatrachydids have spikes extending from the margins of its skull, but it is now classified as a dissorophoid that independently evolved spikes. Stegops was first named by American paleontologist Edward Drinker Cope in 1885, with his description of the type species Stegops divaricata. Cope had also named a species of Sauropleura from Linton in 1875, which he called Sauropleura newberryi. This species was later synonymized with Stegops divaricata when the type specimen of S. newberryi was prepared and found to be a large specimen of Stegops.
Adamanterpeton is a genus of Edopoid Temnospondyl within the family Cochleosauridae. The type species A. ohioensis was named in 1998 and is currently the only known species within this genus. Adamanterpeton is rare in the Linton vertebrate assemblage, with other amphibians like Sauropleura, Ophiderpeton, and Colosteus being more common. Unlike other Linton vertebrates, Adamanterpeton may have been adapted to a terrestrial lifestyle.
Anthracodromeus is an extinct genus of Late Carboniferous "protorothyridid" eureptile known from Ohio. It is known from the holotype AMNH 6940, a nearly complete skeleton. It was collected in the Linton site in Jefferson County, from the Allegheny Group. A. longipes was first assigned by Edward Drinker Cope in 1875 to a species of Sauropleura. The genus was first named by Robert L. Carroll and Donald Baird in 1972 and the type species is Anthracodromeus longipes. It is amongst the oldest known tetrapods to display adaptations for climbing.
The Urocordylidae are an extinct family of nectridean lepospondyl amphibians. Urocordylids lived during the Late Carboniferous and Early Permian in what is now Europe and North America and are characterized by their very long, paddle-like tails. In life, they were probably newt-like and aquatic.
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.
Sauropleurinae is an extinct subfamily of nectridean tetrapodomorphs. Along with the subfamily Urocordylinae, Sauropleurinae is part of the family Urocordylidae. Like other urocordylids, sauropleurines have long, flattened tails and superficially resemble aquatic newts. They differ from urocordylines in having narrow, pointed skulls. Sauropleurinae includes the genera Sauropleura, Crossotelos, Lepterpeton, and Montcellia, which lived during the Late Carboniferous and Early Permian in what is now North America and Europe.
Paleontology or palaeontology is the study of prehistoric life forms on Earth through the examination of plant and animal fossils. This includes the study of body fossils, tracks (ichnites), burrows, cast-off parts, fossilised feces (coprolites), palynomorphs and chemical residues. Because humans have encountered fossils for millennia, paleontology has a long history both before and after becoming formalized as a science. This article records significant discoveries and events related to paleontology that occurred or were published in the year 2023.
