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Sinerpeton Temporal range: | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Amphibia |
Order: | Urodela |
Genus: | † Sinerpeton Gao & Shubin, 2001 |
Type species | |
Sinerpeton fengshanense Gao & Shubin, 2001 | |
Synonyms [1] | |
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Sinerpeton is an extinct genus of salamander from the Late Jurassic of China. [2] It is monotypic and consists of one species, S. fengshanense. [2] [1]
Sinerpeton was recovered from Late Jurassic (Tithonian) fossil beds in Fengshan, China, which overlay the Zhangjiakou Formation. [2] The type species was originally named S. fengshanensis, though was later amended to the proper S. fengshanense. [1]
Sinerpeton retains various characteristics basal to salamanders, including small dorsal processes on the maxillae, nasals that articulate in the midline, separate angular and coronoid bones, and the fusion of the first and second distal carpals. It has unicapitate ribs, similar to cryptobranchoids. Based on its ossified mesopodium and paired ceratobranchials, it was originally suggested that Sinerpeton retained its external gills into adulthood, [2] though ossified ceratobranchials occur in both metamorphosed and neotenic salamanders, and the presence of ossified mesopodial elements suggests it likely underwent conventional metamorphosis. [3]
The Jurassic is a geologic period and stratigraphic system that spanned from the end of the Triassic Period 201.4 million years ago (Mya) to the beginning of the Cretaceous Period, approximately 145 Mya. The Jurassic constitutes the middle period of the Mesozoic Era and is named after the Jura Mountains, where limestone strata from the period were first identified.
Salamanders are a group of amphibians typically characterized by their lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults. All ten extant salamander families are grouped together under the order Urodela from the group Caudata. Urodela is a scientific Latin term based on the Ancient Greek οὐρά δήλη: ourà dēlē "conspicuous tail". Caudata is the Latin for "tailed ones", from cauda: "tail".
The Cryptobranchidae are a family of large salamanders that are fully aquatic. The family includes some of the largest living amphibians. They are native to China, Japan, and the eastern United States. Giant salamanders constitute one of two living families—the other being the Asiatic salamanders belonging to the family Hynobiidae—within the Cryptobranchoidea, one of two main divisions of living salamanders.
The Asiatic salamanders are primitive salamanders found all over Asia, and in European Russia. They are closely related to the giant salamanders, with which they form the suborder Cryptobranchoidea. About half of hynobiids currently described are endemic to Japan, but their range also covers parts of china, Russia, Afghanistan and iran.
The Alytidae are a family of primitive frogs. Their common name is painted frogs or midwife toads. Most are endemic to Europe, but three species occur in northwest Africa, and a species formerly thought to be extinct is found in Israel.
Choristodera is an extinct order of semiaquatic diapsid reptiles that ranged from the Middle Jurassic, or possibly Triassic, to the Miocene. Choristoderes are morphologically diverse, with the best known members being the crocodile-like neochoristoderes such as Champsosaurus. Other choristoderans had lizard-like or long necked morphologies. Choristoderes appear to have been confined to the Northern Hemisphere, having been found in North America, Asia, and Europe, and possibly also North Africa. Choristoderes are generally thought to be derived neodiapsids that are close relatives or members of Sauria.
Gerrothorax is an extinct genus of temnospondyl amphibian from the Triassic period of Greenland, Germany, Poland, Sweden, and possibly Thailand. It is known from a single species, G. pulcherrimus, although several other species such as G. pustuloglomeratus have been named in the past.
Microsauria is an extinct, possibly polyphyletic order of tetrapods from the late Carboniferous and early Permian periods. It is the most diverse and species-rich group of lepospondyls. Recently, Microsauria has been considered paraphyletic, as several other non-microsaur lepospondyl groups such as Lysorophia seem to be nested in it. Microsauria is now commonly used as a collective term for the grade of lepospondyls that were originally classified as members of Microsauria.
The Salamandroidea are a suborder of salamanders, referred to as advanced salamanders. The members of the suborder are found worldwide except for Antarctica, sub-Saharan Africa, and Oceania. They differ from suborder Cryptobranchoidea as the angular and prearticular bones in their lower jaws are fused, their trunk ribs are bicapitate, and all members use internal fertilization. The female is fertilized by means of a spermatophore, a sperm-containing cap placed by the male in her cloaca. The sperm is stored in spermathecae on the roof of the cloaca until it is needed at the time of oviposition.
The Cryptobranchoidea are a suborder of salamanders found in Asia, European Russia, and the United States. They are known as primitive salamanders, in contrast to Salamandroidea, the advanced salamanders. It has two living subdivisions, Cryptobranchidae, and Hynobiidae, commonly known as Asian salamanders.
Albanerpeton is an extinct genus of salamander-like albanerpetontid amphibian found in North America, Europe and Asia first appearing in Cretaceous-aged strata. There are eight described members of the genus, and one undiagnosed species from the Paskapoo Formation, making it by far the most speciose genus in the family. Members of the genus had a robust head and neck which likely allowed them to actively burrow, characteristic of fossorial species, and they lived in a wide range of environments. This genus of amphibian was the last of its order, surviving until into the Early Pleistocene (Gelasian) of northern Italy, and possibly northern Spain, until around 2 million years ago. It likely became extinct when the region developed its present Mediterranean-type climate, having preferred one that was cold and humid. The monophyly of Albanerpeton has recently been questioned, with some authors regarding the genus as paraphyletic.
Chunerpeton tianyiensis is an extinct species of salamander from the Late Jurassic Daohugou Beds in Ningcheng County, Nei Mongol, China. It is the only species classified under the genus Chunerpeton, which means "early creeping animal". It was a small animal measuring 18 cm in length. It was neotenic, with the retention of external gills into adulthood. In the original description it was placed in Cryptobranchidae, which contains modern giant salamanders. A redescription published in 2020 found it to be a stem-group caudatan outside the crown group of modern salamanders. A 2021 study found it to be a member of Cryptobranchoidea outside of Cryptobranchidae. In 2022 a more extensive analysis, with greater character and taxon sampling, recovered Chunerpeton tianyiense as a stem-group caudatan, outside the crown group of modern salamanders, and associated with Beiyanerpeton jianpingensis and Qinglongtriton gangouensis.
Callobatrachus is an extinct genus of frog from the Early Cretaceous-age Yixian Formation of Liaoning, China. It was described in 1999 by K. Gao of the American Museum of Natural History and Y. Wang of the Chinese Academy of Sciences. It was discovered in the Sihetun locality of the western part of Liaoning province.
Iridotriton is an extinct genus of prehistoric salamander known from a fossil found in stratigraphic zone 6 of the late Jurassic Morrison Formation in the Dinosaur National Monument. One species has been described, Iridotriton hechti. It is likely a member of Cryptobranchoidea.
Liaoxitriton is an extinct genus of prehistoric cryptobranchoid salamanders from the Early Cretaceous of China. It contains one species, L. zhongjiani, from the Aptian aged Yixian Formation. A second species, L. daohugouensis from the Middle/Late Jurassic Tiaojishan Formation, was moved to the genus Neimengtriton in 2021 after a number of studies noted morphological differences between the two genera.
Liaobatrachus is a genus of prehistoric frog, the first fossil specimen of which was recovered from the Yixian Formation of Liaoning Province, China. It was the first Mesozoic era frog ever found in China. The species Callobatrachus sanyanensis,Mesophryne beipiaoensis and Yizhoubatrachusmacilentus were classified as species of Liaobatrachus in one study, but this has been rejected by other authors. The genus has been considered a nomen dubium by some authors due to the poor preservation of the holotype specimen. Fossils were found in the Sihetun locality of the western part of Liaoning province, in the lower part of the Yixian Formation, and date to approximately 124.6 Ma. Another specimen was collected near Heitizigou, 25 kilometres (16 mi) south of Beipiao. The specimen has a snout–vent length of 69 millimetres (2.7 in). Liaobatrachus is considered to be the most basal member of Discoglossidae based on phylogenetic analysis.
Laccotriton is an extinct genus of prehistoric salamanders which lived in Eastern Asia during the Early Cretaceous. A nearly complete skeleton of L. subsolanus was found at Hebei, China.
Pangerpeton is an extinct genus of salamanders. Its monotypic species is Pangerpeton sinensis.
The Haifanggou Formation, also known as the Jiulongshan Formation, is a fossil-bearing rock deposit located near Daohugou village of Ningcheng County, in Inner Mongolia, northeastern China.
Beiyanerpeton is an extinct genus of salamandroid amphibians known from the Late Jurassic of western Liaoning Province, China. It contains a single species, B. jianpingensis. Alternative analyses suggest that B. jianpingensis is a stem salamander and not a salamandroid.