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The Sao Khua sclerorhynchoid is an unnamed genus and species of sclerorhynchoid from the Early Cretaceous Sao Khua Formation in Thailand. It is known from the tip of a rostral denticle that is deposited in the Sirindhorn Museum as SM 2012-1-021. The denticle has a single barb similar to Onchopristis , Onchosaurus , and Pucapristis , but is distinguished from all other genera by having a row of enameloid "droplets" on each side. [1] It is one of the earliest sclerorhynchoids, along with Celtipristis and Onchopristis which also appeared in the Barremian. [2]
Rajiformes is one of the four orders in the superorder Batoidea, flattened cartilaginous fishes related to sharks. Rajiforms are distinguished by the presence of greatly enlarged pectoral fins, which reach as far forward as the sides of the head, with a generally flattened body. The undulatory pectoral fin motion diagnostic to this taxon is known as rajiform locomotion. The eyes and spiracles are located on the upper surface of the head and the gill slits are on the underside of the body. Most species give birth to live young, although some lay eggs enclosed in a horny capsule.
Siamotyrannus is a genus of theropod dinosaur from the early Cretaceous of Thailand.
Siamosaurus is a genus of spinosaurid dinosaur that lived in what is now known as China and Thailand during the Early Cretaceous period and is the first reported spinosaurid from Asia. It is confidently known only from tooth fossils; the first were found in the Sao Khua Formation, with more teeth later recovered from the younger Khok Kruat Formation. The only species Siamosaurus suteethorni, whose name honours Thai palaeontologist Varavudh Suteethorn, was formally described in 1986. In 2009, four teeth from China previously attributed to a pliosaur—under the species "Sinopliosaurus" fusuiensis—were identified as those of a spinosaurid, possibly Siamosaurus. It is yet to be determined if two partial spinosaurid skeletons from Thailand and an isolated tooth from Japan also belong to Siamosaurus.
Tangvayosaurus is a genus of sauropod dinosaur from the Aptian-Albian age Lower Cretaceous Gres superieurs Formation of Savannakhet Province, Laos. It was a basal somphospondylan, about 15 m long, and is known from the remains of two or three individuals.
Kinnareemimus is a genus of ornithomimosaurian theropod dinosaur from Thailand. It is known only from incomplete remains discovered no later than the early 1990s that includes vertebrae, partial pubic bones, metatarsals, and an incomplete fibula. The third metatarsal exhibits a distinctive lateral "pinching", known as the "arctometarsalian" condition, variations of which are found in ornithomimosaurs, tyrannosauroids, troodontids, and caenagnathids. Its remains were collected from the Early Cretaceous Sao Khua Formation, dating to the Barremian stage, at Phu Wiang, Khon Kaen Province. Its early occurrence makes it among the earliest ornithomimosaur known, depending on the age of the formation. Buffetaut et al. suggest the fossils of Kinnareemimus may indicate an Asian origin for advanced ornithomimosaurs.
Phuwiangosaurus is a genus of titanosaur dinosaur from the Early Cretaceous (Valanginian-Hauterivian) Sao Khua Formation of Thailand. The type species, P. sirindhornae, was described by Martin, Buffetaut, and Suteethorn in a 1993 press release and was formally named in 1994. The species was named to honor Princess Maha Chakri Sirindhorn of Thailand, who was interested in the geology and palaeontology of Thailand, while the genus was named after the Phu Wiang area, where the fossil was discovered.
Sclerorhynchus is an extinct genus of ganopristid sclerorhynchoid that lived during the Late Cretaceous. The genus Ganopristis is considered a junior synonym of Sclerorhynchus. It was a widespread genus, with fossils found in the Middle East, North Africa, Europe, and North America. While it had a long rostrum with large denticles similar to sawfishes and sawsharks, its closest living relatives are actually skates. Complete specimens of S. atavus show that its fin arrangement was similar to skates, with the pectoral and pelvic fins touching, both dorsal fins located behind the pelvic fins, and a reduced caudal fin.
Ischyrhiza is an extinct genus of sclerorhynchoid ray from the Late Cretaceous and Early Paleogene.
The Sao Khua Formation is a middle member of the Khorat Group. It consists of an alteration of pale red to yellowish-gray, fine to medium-grained sandstone and grayish-reddish brown siltstone and clay. Rare pale red to light gray conglomerates, containing carbonate pebbles, are also characteristic of this formation. This geological formation in Thailand dates to the Early Cretaceous age, specifically the Valanginian through Hauterivian stages.
Siamamia is an extinct genus of ray-finned fish from Northeasthern Thailand. They belong to family Amiidae and are halecomorph fishes endemic to Early Cretaceous freshwater environments in eastern Asia.
Siamosuchus is a genus of goniopholidid mesoeucrocodylian. Its fossils have been recovered from the pre-Aptian-age Lower Cretaceous Sao Khua Formation of eastern Thailand. It is known from a partial skull, most of the right half of the postcranial skeleton, and some bony scutes. Siamosuchus was described by Lauprasert and colleagues in 2007. The type species is S. phuphokensis. Siamosuchus may be closely related to the European genus Goniopholis.
Phu Wiang Dinosaur Museum is a geological museum mainly exhibiting fossils. It is under the administration of the Department of Mineral Resources, Ministry of Natural Resources and Environment, of the Royal Thai Government, and situated in the Khok Sanambin public area in Tambon Nai Muang, Wiang Kao district, Khon Kaen province in the northeastern region of Thailand. The museum was constructed with a budget from the Tourism Authority of Thailand under the supervision of the Department of Mineral Resources and comprises an area of 40 acres (160,000 m2). It has been open to the public since 2009.
The Early Cretaceous Phra Wihan Formation is the second lowest member of the Mesozoic Khorat Group which outcrops in Northeast Thailand.
Harranahynchus is an extinct genus of schizorhizid sclerorhynchoid that lived during the Late Cretaceous. It contains one valid species, H. minutadens. It is known from relatively complete cranial and body fossils found in the Muwaqqar Chalk Marl Formation of Jordan. Its rostral denticles are extremely small and are arranged in batteries like its close relative Schizorhiza. It has an estimated length of around 2 m (6.6 ft).
Camarillasaurus is a genus of spinosaurid dinosaur from the Early Cretaceous period (Barremian) of Camarillas, Teruel Province, in what is now northeastern Spain. Described in 2014, it was originally identified as a ceratosaurian theropod, before being referred to the Spinosauridae in 2021.
Sclerorhynchoidei is an extinct suborder of rajiform rays that had long rostra with large denticles similar to sawfishes and sawsharks. This feature was convergently evolved and their closest living relatives are actually skates. While they are often called "sawfishes", sawskates is a more accurate common name for sclerorhynchoids. The suborder contains five named families: Ganopristidae, Ischyrhizidae, Onchopristidae, Ptychotrygonidae, and Schizorhizidae. Several genera are not currently placed in any of these families. Sclerorhynchoids first appeared in the Barremian and went extinct during the Cretaceous–Paleogene extinction event, with former Paleocene occurrences being misidentifications or reworked specimens.
Atlanticopristis is an extinct genus of sclerorhynchid that lived during the Middle Cretaceous (Cenomanian) of what is now the Northeast Region of Brazil, between 100.5 and 93.9 million years ago. Fourteen fossil teeth from Atlanticopristis were found in the Alcântara Formation, and referred to the closely related Onchopristis in 2007; a redescription in 2008 by Brazilian paleontologists Manuel Medeiros and Agostinha Pereira assigned it to a new genus containing one species, Atlanticopristis equatorialis.
Varavudh Suteethorn, or Warawut Suteethorn is a Thai palaeontologist and geologist. He is the current director of the Palaeontological Research and Education Centre, Mahasarakham University. He is best known for his work on vertebrate paleontology in northeastern Thailand, having contributed to the discovery of many fossil taxa and dig sites in the Khorat Plateau, as a part of a long-standing collaboration between Thai and French scientists.
Phuwiangvenator is an extinct genus of megaraptoran theropod that lived during the Early Cretaceous period in what is now Thailand. It contains only the type species, P. yaemniyomi. The generic name of Phuwiangvenator comes from the Phu Wiang mountains, where the holotype was discovered, and the Latin word "venator" meaning hunter. The specific name, "yaemniyomi", is in honor of Sudham Yaemniyom, who was a historical paleontologist from Thailand and the first person to discover fossils there.
Vayuraptor is a genus of basal coelurosaurian theropod dinosaur that lived in the Early Cretaceous (Barremian) Sao Khua Formation of Thailand. The genus contains a single species, V. nongbualamphuensis, known from a partial skeleton.