Acipenseriformes is an order of basal ray-finned fishes that includes living and fossil sturgeons and paddlefishes (Acipenseroidei), as well as the extinct families Chondrosteidae and Peipiaosteidae. They are the second earliest diverging group of living ray-finned fish after the bichirs. Despite being early diverging, they are highly derived, having only weakly ossified skeletons that are mostly made of cartilage, and in modern representatives highly modified skulls.
Paddlefish are a family of ray-finned fish belonging to order Acipenseriformes, and one of two living groups of the order alongside sturgeons (Acipenseridae). They are distinguished from other fish by their elongated rostra, which are thought to enhance electroreception to detect prey. Paddlefish have been referred to as "primitive fish" because the Acipenseriformes are among the earliest diverging lineages of ray-finned fish, having diverged from all other living groups over 300 million years ago. Paddlefish are almost exclusively North American and Chinese, both extant and in the fossil record.
The Chinese paddlefish, also known as the Chinese swordfish, is an extinct species of fish that was formerly native to the Yangtze and Yellow River basins in China. With records of specimens over three metres and possibly 7 m (23 ft) in length, it was one of the largest species of freshwater fish. It was the only species in the genus Psephurus and one of two recent species of paddlefish (Polyodontidae), the other being the American paddlefish. It was an anadromous species, meaning that it spent part of its adult life at sea, while migrating upriver to spawn.
Hyphalosaurus is a genus of freshwater aquatic reptiles, belonging to the extinct order Choristodera. They lived during the early Cretaceous period, about 122 million years ago. The genus contains two species, H. lingyuanensis and H. baitaigouensis, both from the Yixian Formation of Liaoning Province, China. They are among the best-known animals from the Jehol Biota, with thousands of fossil specimens representing all growth stages in scientific and private collections.
Edaphodon was a fish genus of the family Callorhinchidae. As a member of the Chimaeriformes, Edaphodon was a type of rabbitfish, a cartilaginous fish related to sharks and rays. The genus appeared in the Aptian age of the Lower Cretaceous and vanished in the Pliocene. It was most prominent during the Late Cretaceous. Many Edaphodon species were found in the Northern Hemisphere, but species from the Southern Hemisphere are also known.
Terminonatator is a genus of elasmosaurid plesiosaur from the Late Cretaceous of Saskatchewan, Canada. It is known from a skull and partial skeleton from a young adult, found in the Campanian-age Bearpaw Formation near Notukeu Creek in Ponteix. Terminonatator is currently one of the youngest plesiosaurs from the Western Interior Seaway.
Rugosuchus is an extinct genus of neosuchian crocodyliform from the late Early Cretaceous of China. It is known from most of a skull, a partial postcranial skeleton, and a second partial skeleton including part of the hips. It was described by Xiao-Chun Wu and colleagues in 2001, with R. nonganensis as the type species. At the time of its description, it was the most complete crocodyliform from northeastern China, and only the second known.
Mesophryne beipiaoensis is an extinct species of frog, from the Cretaceous Yixian Formation of Liaoning (China), and the only species in the genus Mesophryne. It is known from a single specimen collected near Heitizigou, 25 kilometres (16 mi) south of Beipiao, from which the specific epithet derives. The specimen has a snout–vent length of 69 millimetres (2.7 in). While some authors have suggested Mesophryne is a synonym of Liaobatrachus, this has been rejected by other authors. In a phylogenetic analysis it was found to be a crown group frog, which was more derived than Ascaphus and Leiopelma, but less so than alytids and other more advanced frogs.
Carsosaurus is a genus of extinct amphibious reptiles, in the mosasaur superfamily, containing only the species Carsosaurus marchesetti. It is known from a single individual that lived during the Upper Cretaceous in what is now Slovenia. The specimen is well-preserved, containing many different bones as well as some skin impressions and sternal cartilage. While more remains are needed to be certain, it is generally thought to belong to Aigialosauridae. In life, it was an amphibious creature that spent most of its time on land, although its later relatives would become fully aquatic.
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.
Palaeopsephurus is an extinct genus of paddlefish (Polyodontidae). At present the genus contains the single species Palaeopsephurus wilsoni. The genus is known from the Late Cretaceous (Maastrichtian) aged Hell Creek Formation of Montana.
Raptorex is a genus of tyrannosaurid dinosaur. Its fossil remains consist of a single juvenile specimen probably uncovered in Mongolia, or possibly northeastern China. The type species is R. kriegsteini, described in 2009 by Sereno and colleagues. The genus name is derived from Latin raptor, "robber", and rex, "king". The specific name honours Roman Kriegstein, a survivor of the Holocaust, whose son Henry Kriegstein donated the specimen to the University of Chicago for scientific study.
Longicrusavis is an extinct genus of basal ornithuromorph bird found only at Dawangzhangzi village in Liaoning Province, China. Longicrusavis was a ground dwelling carnivore, a wader, and part of biological family Hongshanornithidae, considered to have been a dominant species in the Jehol Biota, the prehistoric Chinese ecosystem which supported them. The name Hongshanornithidae represents one of China's oldest recorded cultures in the region, the Hongshan culture.
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.
Mesoraphidiidae is an extinct family of snakeflies in the suborder Raphidiomorpha. The family lived from the Late Jurassic through the Late Cretaceous and is known from twenty-five genera. Mesoraphidiids have been found as both compression fossils and as inclusions in amber. The family was first proposed in 1925 by the Russian paleoentomologist Andrey Vasilyevich Martynov based on Upper Jurassic fossils recovered in Kazakhstan. The family was expanded in 2002 by the synonymizing of several other proposed snakefly families. The family was divided into three subfamilies and one tribe in a 2011 paper, further clarifying the relationships of the included genera.
Ptilotodon is an extinct genus of teiid lizard from the Early Cretaceous of Oklahoma. The type and only known species is Ptilotodon wilsoni, named in 2002 on the basis of a single lower jaw with four teeth found in the Antlers Formation. The small size of the specimen may be an indication that it belonged to a juvenile.
Crossopholis is an extinct fish known from the early Eocene (Ypresian) of North America, approximately 52 million years ago. It is a close relative of the contemporary American paddlefish, belonging to the paddlefish family Polyodontidae.
Peipiaosteidae is an extinct family of fish, known from the Late Jurassic and Early Cretaceous of Asia. They are members of Acipenseriformes, related to sturgeons (Acipenseridae) and paddlefish (Polyodontidae). Fossils have been found in freshwater deposits in China, Russia, Kazakhstan, and Mongolia. They are generally considered either the earliest diverging group of Acipenseriformes, or the sister group to the clade containing Acipenseridae and Polyodontidae. At least Yanosteus was likely to have been piscivorous, based on a specimen of Lycoptera found in the mouth of one specimen.
Australopachycormus is an extinct genus pachycormiform fish. It is only known from the type species, A. hurleyi, from the Early Cretaceous (Albian) Toolebuc Formation of Queensland, Australia. Like the related Protosphyraena, it possessed an elongated rostrum.
Parapsephurus is an extinct genus of paddlefish in the family Polyodontidae. Currently the only known species in this genus is the type species, Parapsephurus willybemisi.P. willybemisi is known a nearly complete specimen from the Tanis locality of the Hell Creek Formation in North Dakota, USA, which dates to the late Maastrichtian stage of the Late Cretaceous, approximately 66 million years ago.
