Jeholotriton Temporal range: Middle or Late Jurassic, | |
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Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Amphibia |
Order: | Urodela |
Suborder: | Cryptobranchoidea |
Genus: | † Jeholotriton Wang, 2000 |
Type species | |
†Jeholotriton paradoxus Wang, 2000 |
Jeholotriton is a genus of primitive salamander from the Daohugou Beds (possibly dating to the late Jurassic period) near Daohugou village of Inner Mongolia, China.
Wang Yuan from the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences first described the species in 2000. [1] In 2005, he presented a full description in the Journal of Vertebrate Paleontology along with C. S. Rose from James Madison University, United States. [2]
The genus name "Jehol-" refers to Jehol Biota, which flourished during the Early Cretaceous in northeastern China. The original naming paper (Wang, 2000) regarded the salamander a member of the biota, but recent studies reveals this fossil-bearing Daohugou Beds is lower, Middle/Late Jurassic in age. The specific name "paradoxus" refers to the strange skull morphology of the animal.
A phylogenetic analysis by Wang and S.E. Evans in 2006 found that Jeholotriton is a possible sister taxon to Pangerpeton , a short-bodied salamander from an adjacent locality in Lingyuan, Liaoning, strata comparable to the Daohugou Beds. These two taxa are close to the base of crown−group Urodela (modern salamanders), either just outside it or just within. [3]
Sinobaatar is a genus of extinct mammal from the Lower Cretaceous of China. It is categorized within the also extinct order Multituberculata and among these it belongs to the plagiaulacid lineage. Sinobaatar was a small herbivore during the Mesozoic era, commonly called "the age of the dinosaurs". The genus was named by Hu Y. and Wang Y. in 2002. Three species have been described.
The Caudata are a group of amphibians containing the extant salamanders (Urodela) and all extinct species of amphibians more closely related to salamanders than to frogs. They are typically characterized by a superficially 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.
Castorocauda is an extinct, semi-aquatic, superficially otter-like genus of docodont mammaliaforms with one species, C. lutrasimilis. It is part of the Yanliao Biota, found in the Daohugou Beds of Inner Mongolia, China dating to the Middle to Late Jurassic. It was part of an explosive Middle Jurassic radiation of Mammaliaformes moving into diverse habitats and niches. Its discovery in 2006, along with the discovery of other unusual mammaliaforms, disproves the previous hypothesis of Mammaliaformes remaining evolutionarily stagnant until the extinction of the non-avian dinosaurs.
Lycoptera is an extinct genus of fish that lived from the late Jurassic to Cretaceous periods in present-day China, North Korea, Mongolia and Siberia. It is known from abundant fossils representing sixteen species, which serve as important index fossil used to date geologic formations in China. Along with the genus Peipiaosteus, Lycoptera has been considered a defining member of the Jehol Biota, a prehistoric ecosystem famous for its feathered dinosaurs, which flourished for 20 million years during the Early Cretaceous, where it occurs abundantly in often monospecific beds, where they are thought to have died in seasonal mass death events. Lycoptera is a crown group teleost belonging to an early diverging lineage of the Osteoglossomorpha, which contains living mooneyes, arapaima, arowana, elephantfish and knifefish/featherbacks.
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 2000.
The Jehol Biota includes all the living organisms – the ecosystem – of northeastern China between 133 and 120 million years ago. This is the Lower Cretaceous ecosystem which left fossils in the Yixian Formation and Jiufotang Formation. These deposits are composed of layers of tephra and sediment. It is also believed to have left fossils in the Sinuiju series of North Korea. The ecosystem in the Lower Cretaceous was dominated by wetlands and numerous lakes. Rainfall was seasonal, alternating between semiarid and mesic conditions. The climate was temperate. The Jehol ecosystem was interrupted periodically by ash eruptions from volcanoes to the west. The word "Jehol" is a historical transcription of the former Rehe Province.
Gobiconodon is an extinct genus of carnivorous mammal from the Middle Jurassic to Early Cretaceous. It weighed 5.4 kilograms (12 lb), had a skull of 10 cm (3.9 in) in length, and had 35 cm (14 in) in presacral body length. It was one of the largest mammals known from the Mesozoic. Like other gobiconodontids, it possesses several speciations towards carnivory, such as shearing molar teeth, large canine-like incisors and powerful jaw and forelimb musculature, indicating that it probably fed on vertebrate prey; rather uniquely among predatory mammals and other eutriconodonts, the lower canines were vestigial, with the first lower incisor pair having become massive and canine-like. Like the larger Repenomamus there might be some evidence of scavenging.
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. 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.
Eoscapherpeton is an extinct genus of giant salamander, known from the Late Cretaceous of Central Asia. Fossils have been found in the Cenomanian aged Khodzhakul Formation and Dzharakuduk Formation, Turonian aged Bissekty Formation and the Coniacian-Santonian aged Aitym Formation of Uzbekistan, the Santonian aged Yalovach Formation of Tajikistan, and the Santonian-lower Campanian aged Bostobe Formation and Campanian aged Darbasa Formation of Kazakhstan.
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 Daohugou Beds, 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.
Pangerpeton is an extinct genus of salamanders. Its monotypic species is Pangerpeton sinensis.
The Tiaojishan Formation is a geological formation in Hebei and Liaoning, People's Republic of China, dating to the middle-late Jurassic period. It is known for its exceptionally preserved fossils, including those of plants, insects and vertebrates. It is made up mainly of pyroclastic rock interspersed with basic volcanic and sedimentary rocks. Previously, the Tiaojishan Formation was grouped together with the underlying Haifanggou Formation as a single "Lanqi Formation." The Tiaojishan Formation forms a key part of the Yanliao Biota assemblage, alongside the Haifanggou Formation.
The Yixian Formation is a geological formation in Jinzhou, Liaoning, People's Republic of China, that spans about 1.6 million years during the early Cretaceous period. It is known for its fossils, listed below.
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.
Liushusaurus is an extinct genus of lizard described by Susan E. Evans and Yuan Wang in 2010. The genus has a single species, Liushusaurus acanthocaudata, and is known from eight fossils, several of which preserve soft tissue detail. The specimens were found in the Lower Cretaceous aged Yixian Formation of Northeast China. Liushusaurus is one of eight lizards that are known and have been named from the Yixian Formation, part of the diverse Jehol Biota ecosystem.
Daohugoupterus is a genus of pterosaur from the Middle to Late Jurassic Daohugou Beds of the Tiaojishan Formation in Inner Mongolia, China.
Liaodactylus is a genus of filter-feeding ctenochasmatid pterosaur from the Jurassic of China. The genus contains one species, L. primus, described by Zhou et al. in 2017. As an adaptation to filter-feeding, Liaodactylus had approximately 150 long, comb-like teeth packed closely together. It is both the earliest known ctenochasmatid and the first filter-feeding pterosaur from the Jurassic Tiaojishan Formation. Later and more specialized ctenochasmatids differ from Liaodactylus in having longer snouts, smaller openings in the skull, and more teeth. Within the Ctenochasmatidae, Liaodactylus was most closely related to the European Ctenochasma.
The Yanliao Biota is the name given to an assembly of fossils preserved in northeastern China from the Middle to Late Jurassic. It includes fossils from the Tiaojishan Formation, Lanqi Formation, Jiulongshan Formation and Haifanggou Formation. This spans approximately 199 to 146 million years ago.
Archisargidae is an extinct family of brachyceran flies known from the Jurassic and Cretaceous periods. It is part of the extinct superfamily Archisargoidea. Most members of the family are known from the Callovian-Oxfordian Daohugou biota of Inner Mongolia, China, and the equivalently aged Karabastau Formation of Kazakhstan. The family has been found to be paraphyletic with respect to Eremochaetidae in a cladistic analysis.