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 type 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.
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.
Thalattosuchia is the name given to a clade of marine crocodylomorphs from the Early Jurassic to the Early Cretaceous that had a cosmopolitan distribution. They are colloquially referred to as marine crocodiles or sea crocodiles, though they are not members of Crocodilia. The clade contains two major subgroupings, the Teleosauroidea and Metriorhynchoidea. Within Metriorhynchoidea, the Metriorhynchidae displayed extreme adaptions for life in the open ocean, including the transformation of limbs into flippers, the development of a tail fluke, and smooth, scaleless skin.
Goniopholididae is an extinct family of moderate-sized semi-aquatic crocodyliforms superficially similar to living crocodiles. They lived between the Early Jurassic and the Late Cretaceous.
Eusuchia is a clade of crocodylomorphs that first appeared in the Early Cretaceous with Hylaeochampsa. Along with Dyrosauridae and Sebecosuchia, they were the only crocodyliformes who survived the K-T extinction. Since the other two clades died out 47 and 11 million years ago respectively, all living crocodilian species are eusuchians, as are many extinct forms.
Hybodontiformes, also called hybodonts, are an extinct subset of Elasmobranchii which existed from the late Devonian to the Late Cretaceous. They form the group of sharks closest to neoselachians, the clade of modern sharks and rays. Hybodonts were named and are distinguished based on their conical tooth shape. They comprised the main group of Jurassic sharks in Europe and North America. They survived into the Late Cretaceous before going extinct, possibly due to competition from other sharks. Lonchidion was one of the last hybodonts — its distinctive serrated fine spines occur in freshwater deposits from Wyoming alongside the fossils of the last non-avian dinosaurs, including Tyrannosaurus rex and Triceratops. Hybodontiformes are identified in the fossil record predominantly based on distinct teeth and fin spines. They were known to live in both fresh and salt water environments.
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.
Gilchristosuchus is an extinct genus of neosuchian crocodyliform. Its fossils have been found in the upper Milk River Formation of Alberta, Canada, in rocks of either latest Santonian or earliest Campanian age. Gilchristosuchus was described in 1993 by Wu and Brinkman. The type species is G. palatinus, in reference to its distinctive palatine bones.
Brillanceausuchus is an extinct genus of atoposaurid crocodylomorph. Fossils have been found in Early Cretaceous–age rocks of Cameroon. The genus is notable for the position of the secondary choana within its palate. Parts of the pterygoid bones make up the rostral margin of the choana and thus separate it from the palatines, a feature also seen in the more advanced neosuchian suborder Eusuchia. This characteristic was once thought to be characteristic of Eusuchia, but its presence in Brillanceausuchus suggests that the trait is homoplasic, thus making the evolution of the position of the choana within crocodilians more complex than previously thought.
Turanosuchus is an extinct genus of paralligatorid crocodyliform. It is based on PIN 2229/507, a partial lower jaw consisting of the area where the two halves of the lower jaw meet. This specimen was found in rocks of the lower Santonian-age Upper Cretaceous Bostobe Svita of Shakh-Shakh, southern Kazakhstan. Turanosuchus was described in 1988 by Mikhail Efimov. The type species is T. aralensis. Halliday et al. (2015) revised the material attributed to T. aralensis and concluded that it represents non-diagnostic neosuchian material, and as such the genus was considered to be a nomen dubium.
Stolokrosuchus is an extinct genus of neosuchian crocodylomorph that lived during the Early Cretaceous. Its fossils, including a skull with a long thin snout and bony knobs on the prefrontal, have been found in Niger. Stolokrosuchus was described in 2000 by Hans Larsson and Boubacar Gado. The type species is S. lapparenti. They initially described it as related to Peirosauridae, if not a member of that family. One study has shown it to be related to Elosuchus. However, more recent works usually find Stolokrosuchus to be one of the basalmost neosuchian, only distantly related to the elosuchid or pholidosaurid, Elosuchus.
Basilochelys is an extinct genus of land turtle which existed during the early Cretaceous period (Berriasian). Containing the sole species Basilochelys macrobios, its fossils have been found in the Phu Kradung Formation of Northeast Thailand. It is considered to be the most basal member of the group Trionychoidae.
The Early Cretaceous Phu Kradung Formation is the lowest member of the Mesozoic Khorat Group which outcrops on the Khorat Plateau in Isan, Thailand. This geological formation consists of micaceous, brown to reddish-brown siltstone beds with minor brown and grey shale and sandstone beds. Occasional lime-noduled conglomerate occurs.
Sunosuchus is an extinct genus of goniopholidid mesoeucrocodylian. Fossils are known from China, Kyrgyzstan, and Thailand and are Jurassic in age, although some may be Early Cretaceous. Four species are currently assigned to the genus: the type species S. miaoi and the species S. junggarensis, S. shartegensis, and S. shunanensis. All species are from China. Goniopholis phuwiangensis, also from Thailand, was reassigned to Sunosuchus by Andrade et al. (2011). The material from Kyrgyzstan has not been assigned to any species.
Theriosuchus is an extinct genus of atoposaurid neosuchian from Late Jurassic to Early Cretaceous of Europe, Southeast Asia (Thailand) and western North America (Wyoming), with fragmentary records from Middle Jurassic and Early Cretaceous sites in China, Morocco, and Scotland.
Susisuchus is an extinct genus of neosuchian mesoeucrocodylian crocodyliform from the Early Cretaceous of Brazil. Fossils have been found from the Nova Olinda Member of the Aptian-age Crato Formation in the Araripe and Lima Campos Basins of northeastern Brazil. Named in 2003, Susisuchus is the sole member of the family Susisuchidae, and is closely related to the clade Eusuchia, which includes living crocodilians. The type species is S. anatoceps, known from a single partial articulated skeleton that preserves some soft tissue. A second species, S. jaguaribensis, was named in 2009 from fragmentary remains.
Chalawan is an extinct genus of pholidosaurid mesoeucrocodylian known from the Late Jurassic or Early Cretaceous Phu Kradung Formation of Nong Bua Lamphu Province, northeastern Thailand. It contains a single species, Chalawan thailandicus, with Chalawan shartegensis as a possible second species.
Coelognathosuchia is an extinct clade of neosuchian crocodyliforms that includes all taxa more closely related to the family Pholidosauridae than to Bernissartia fagesii or Eusuchia. Martin et al. (2014) named the clade after finding goniopholidids and pholidosaurids to group together in their phylogenetic analysis of crocodyliform evolutionary relationships. In their analysis, Pholidosauridae was monophyletic and Goniopholididae was paraphyletic, being an assemblage of successively more basal taxa within Coelognathosuchia. Coelognathosuchia itself was positioned near the base of the larger clade Neosuchia as the sister group to a clade containing the Early Cretaceous neosuchian Bernissartia and Eusuchia, the group that includes all modern crocodilians and their closest extinct relatives.
Varavudh Suteethorn, or Warawut Suteethorn is a Thai geologist and palaeontologist. He is the current director of the Palaeontological Research and Education Centre, Mahasarakham University. He is best known for his work on vertebrate palaeontology 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.
Indosinosuchus is a genus of teleosaurid neosuchian that lived during the Late Jurassic in what is now Thailand. It contains two species, the type species I. potamosiamensis and I. kalasinensis, both recovered from the lower Phu Kradung Formation. The age of Indosinosuchus is unclear, as vertebrate fossils like Indosinosuchus support a Late Jurassic age, while palynological data suggests an Early Cretaceous (Berriasian) age.
