| Adelospondylus Temporal range: Carboniferous, | |
|---|---|
 | |
| Life restoration | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Clade: | Sarcopterygii |
| Clade: | Tetrapodomorpha |
| Order: | † Adelospondyli |
| Family: | † Adelogyrinidae |
| Genus: | † Adelospondylus Carroll, 1967 |
| Type species | |
| Adelospondylus watsoni Carroll, 1967 | |
Adelospondylus is an extinct adelospondyl tetrapodomorph from the Carboniferous of what is now Scotland. [1] [2]
"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.
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.
Adelospondyli is an order of elongated, presumably aquatic, Carboniferous amphibians. They have a robust skull roofed with solid bone, and orbits located towards the front of the skull. The limbs were almost certainly absent, although some historical sources reported them to be present. Despite the likely absence of limbs, adelospondyls retained a large part of the bony shoulder girdle. Adelospondyls have been assigned to a variety of groups in the past. They have traditionally been seen as members of the subclass Lepospondyli, related to other unusual early tetrapods such as "microsaurs", "nectrideans", and aïstopods. Analyses such as Ruta & Coates (2007) have offered an alternate classification scheme, arguing that adelospondyls were actually far removed from other lepospondyls, instead being stem-tetrapod stegocephalians closely related to the family Colosteidae.
Lethiscus is the earliest known representative of the Aistopoda, a group of very specialised snake-like tetrapodomorphs known from the early Carboniferous (Mississippian).
Robert "Bob" Lynn Carroll was an American–Canadian vertebrate paleontologist who specialised in Paleozoic and Mesozoic amphibians and reptiles.
The Visean, Viséan or Visian is an age in the ICS geologic timescale or a stage in the stratigraphic column. It is the second stage of the Mississippian, the lower subsystem of the Carboniferous. The Visean lasted from 346.7 to 330.9 Ma. It follows the Tournaisian age/stage and is followed by the Serpukhovian age/stage.
Eryopoidea is a clade of late Carboniferous and Permian temnospondyl amphibians, known from North America and Europe. Carroll (1998) includes no fewer than ten families, but Yates and Warren (2000) replaced this with a cladistic approach that includes three closely-related families, the Eryopidae, Parioxyidae and Zatrachydidae. They define the Eryopoidea as all members of Euskelia in which the choana are relatively rounded and the iliac blade is vertical. A similar definition is provided by Laurin and Steyer (2000).
Eryopidae were a group of medium to large amphibious temnospondyls, known from North America and Europe. They are defined as all eryopoids with interpterygoid vacuities that are rounded at the front; and large external nares. Not all of the genera previously included in the Eryopidae are retained under the cladistic revisions.
Dendrerpeton is a genus of an extinct group of temnospondyl amphibians. Its fossils have been found primarily in the Joggins Formation of Eastern Canada and in Ireland. It lived during the Carboniferous and is said to be around 309–316 million years of age, corresponding to more specifically the Westphalian (stage) age. Of terrestrial temnospondyl amphibians evolution, it represents the first stage. Although multiple species have been proposed, the species unanimously recognized is D. acadianum. This species name comes from “Acadia” which is a historical name for the Nova Scotia region as a French colony. It refers to the location of the coal field at which the fossil was found.
Gephyrostegus is a genus of extinct gephyrostegid reptiliomorph amphibian. It was a small animal at 22 cm snout-vent length, of generally lizard-like build and presumably habit. It had large eyes and a large number of small, pointed teeth, indicating it was an active insectivorous hunter. The remains have been found in Nýřany, Czech Republic, dating from around 310 million years ago.
Acherontiscus is an extinct genus of stegocephalians that lived in the Early Carboniferous of Scotland. The type and only species is Acherontiscus caledoniae, named by paleontologist Robert Carroll in 1969. Members of this genus have an unusual combination of features which makes their placement within amphibian-grade tetrapods uncertain. They possess multi-bone vertebrae similar to those of embolomeres, but also a skull similar to lepospondyls. The only known specimen of Acherontiscus possessed an elongated body similar to that of a snake or eel. No limbs were preserved, and evidence for their presence in close relatives of Acherontiscus is dubious at best. Phylogenetic analyses created by Marcello Ruta and other paleontologists in the 2000s indicate that Acherontiscus is part of Adelospondyli, closely related to other snake-like animals such as Adelogyrinus and Dolichopareias. Adelospondyls are traditionally placed within the group Lepospondyli due to their fused vertebrae. Some analyses published since 2007 have argued that adelospondyls such as Acherontiscus may not actually be lepospondyls, instead being close relatives or members of the family Colosteidae. This would indicate that they evolved prior to the split between the tetrapod lineage that leads to reptiles (Reptiliomorpha) and the one that leads to modern amphibians (Batrachomorpha). Members of this genus were probably aquatic animals that were able to swim using snake-like movements.
Boii is an extinct genus of microsaur within the family Tuditanidae. It was found in Carboniferous coal from mines near the community of Kounov in the Czech Republic. The only remains of the genus consist of a crushed skull, shoulder girdle bones, and scales, which were similar to microsaurian elements originally referred to Asaphestera. Boii can be characterized by its heavily sculptured skull, thin ventral plate of the clavicles, and a larger number of fangs on the roof of the mouth. For many years the type and only known species, Boii crassidens, was considered to be a species of Sparodus, until 1966 when Robert Carroll assigned it to its own genus.
Crinodon is an extinct genus of microsaur within the family Tuditanidae. The type and only species C. limnophyes was found in Carboniferous deposits of Nyrany and described by M. C. Steen in 1938 as Ricnodon limnophyes. It was assigned to the new genus Crinodon by R. L. Carroll and P. Gaskill in 1978.
Limnerpeton is an extinct genus of dissorophoidean euskelian temnospondyl within the family Amphibamidae.
Tuditanus is an extinct genus of tuditanid microsaur from the Carboniferous, ~ 306 Ma ago. It was of small size, reaching a length of about 24 cm.
Coelostegus is an extinct genus of Late Carboniferous basal reptile known from Pilsen of Czech Republic. It is known from the holotype ČGH 3027, a partial skeleton of an immature individual. It was collected in the Nýřany site from the Nýřany Member of the Kladno Formation. It was first named by Robert L. Carroll and Donald Baird in 1972 and the type species is Coelostegus prothales. The most recent phylogenic study of primitive reptile relationships found Coelostegus to be the basalmost known eureptile.
Brouffia is an extinct genus of Late Carboniferous basal reptile known from Pilsen of Czech Republic. It is known from a single partial skeleton, the holotype ČGH III B.21.C.587 and MP 451. It was collected in the Nýřany site from the Nýřany Member of the Kladno Formation. It was first named by Robert L. Carroll and Donald Baird in 1972 and the type species is Brouffia orientalis.
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.
Cephalerpeton is an extinct genus of "protorothyridid" eureptile known from the Late Carboniferous of Illinois.
The Junggar Basin, also known as the Dzungarian Basin or Zungarian Basin, is one of the largest sedimentary basins in Northwest China. It is located in Dzungaria in northern Xinjiang, and enclosed by the Tarbagatai Mountains of Kazakhstan in the northwest, the Altai Mountains of Mongolia in the northeast, and the Heavenly Mountains in the south. The geology of Junggar Basin mainly consists of sedimentary rocks underlain by igneous and metamorphic basement rocks. The basement of the basin was largely formed during the development of the Pangea supercontinent during complex tectonic events from Precambrian to late Paleozoic time. The basin developed as a series of foreland basins – in other words, basins developing immediately in front of growing mountain ranges – from Permian time to the Quaternary period. The basin's preserved sedimentary records show that the climate during the Mesozoic era was marked by a transition from humid to arid conditions as monsoonal climatic effects waned. The Junggar basin is rich in geological resources due to effects of volcanism and sedimentary deposition. According to Guinness World Records it is a land location remotest from open sea with great-circle distance of 2,648 km from the nearest open sea at 46°16′8″N86°40′2″E.
2D, stereoscopic, and 3D imagery of the type specimen of Adelospondylus watsoni
 | This article about a tetrapodomorph is a stub. You can help Wikipedia by expanding it. |
