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Theretairus
''Theretairus'' is a Late Jurassic genus of sphenodont reptile from the Morrison Formation of western North America,Foster, J. (2007). "Table 2.1: Fossil Vertebrates of the Morrison Formation." ''Jurassic West: The Dinosaurs of the Morrison Formation and Their World''. Indiana University Press. pp. 58-59. present in stratigraphic zones 5 and 6.Foster, J. (2007). "Appendix." ''Jurassic West: The Dinosaurs of the Morrison Formation and Their World''. Indiana University Press. pp. 327-329. History and naming The holotype consists of a right mandible and several in-socket teeth from Quarry 9 at Como Bluff, Wyoming where it was excavated by paleontologist William Harlow Reed, who then was working for Othniel Charles Marsh, and it was deposited at the Yale Peabody Museum under YPM VP 13764. The locality comes from strata of the Brushy Basin Member of the Morrison Formation, which also bears other sphenodontians ''Opisthias'' and ''Eilenodon.''Rasmussen, T. E.; Callison, George (198 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Como Bluff
Como Bluff is a long ridge extending east–west, located between the towns of Rock River and Medicine Bow, Wyoming. The ridge is an anticline, formed as a result of compressional geological folding. Three geological formations, the Sundance, the Morrison, and the Cloverly Formations, containing fossil remains from the Late Jurassic of the Mesozoic Era are exposed. Nineteenth-century paleontologists discovered many well-preserved specimens of dinosaurs, as well as mammals, turtles, crocodilians, and fish from the Morrison Formation. Because of this, Como Bluff is considered to be one of the major sites for the early discovery of dinosaur remains. Among the species discovered is the only known specimen of ''Coelurus''. Significant discoveries were made in 22 different areas scattered along the entire length of the ridge. It is included on the National Register of Historic Places as well as the National Natural Landmark list. History of discovery The discovery of dinosaurs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphenocondor
''Sphenocondor'' is an extinct genus of sphenodontian reptile from the Early Jurassic Cañadón Asfalto Formation of Argentina. Phylogeny A phylogenetic analysis performed by Apestiguia et al. (2012) resulted in the following tree which shows the relationship of ''Sphenocondor'' to other rhynchocephalia Rhynchocephalia (; ) is an order of lizard-like reptiles that includes only one living species, the tuatara (''Sphenodon punctatus'') of New Zealand. Despite its current lack of diversity, during the Mesozoic rhynchocephalians were a diverse g ...ns: References Prehistoric reptile genera Jurassic lepidosaurs Middle Jurassic reptiles of South America Cañadón Asfalto Formation Fossil taxa described in 2012 {{jurassic-reptile-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphenodont
Rhynchocephalia (; ) is an order of lizard-like reptiles that includes only one living species, the tuatara (''Sphenodon punctatus'') of New Zealand. Despite its current lack of diversity, during the Mesozoic rhynchocephalians were a diverse group including a wide array of morphologically distinct forms. The oldest record of the group is dated to the Middle Triassic around 238 to 240 million years ago, and they had achieved a worldwide distribution by the Early Jurassic. Most rhynchocephalians belong to the group Sphenodontia ('wedge-teeth'). Their closest living relatives are lizards and snakes in the order Squamata, with the two orders being grouped together in the superorder Lepidosauria. Many of the niches occupied by lizards today were held by sphenodontians during the Triassic and Jurassic, although lizard diversity began to overtake sphenodontian diversity in the Cretaceous, and they had disappeared almost entirely by the beginning of the Cenozoic. While the modern tuatara ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Opisthias
''Opisthias'' is a genus of sphenodont reptile. The type species, ''Opisthias rarus'', is known from the Late Jurassic (Kimmeridgian-Tithonian) Morrison Formation of western North America, present in stratigraphic zones 2 and 4–6. Distribution ''Opisthias'' is primarily known to have lived during the Late Jurassic in the United States (Colorado, Utah, and Wyoming). Other remains are also known from the Late Jurassic of Portugal. A undescribed crushed skull (DINO 16454) has been attributed to this genus by some sources, though this has been strongly disputed by others. Berriasian records A lower jaw is also known from the Berriasian aged Lulworth Formation of the United Kingdom, which appears to be distinct from the type North American species. A fragmentary dentary possibly attributable to ''Opisthias'' is also known from the Berriasian aged Angeac-Charente bonebed in France.Ronan Allain, Romain Vullo, Lee Rozada, Jérémy Anquetin, Renaud Bourgeais, et al.Vertebrate paleobiod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhynchocephalia
Rhynchocephalia (; ) is an order of lizard-like reptiles that includes only one living species, the tuatara (''Sphenodon punctatus'') of New Zealand. Despite its current lack of diversity, during the Mesozoic rhynchocephalians were a diverse group including a wide array of morphologically distinct forms. The oldest record of the group is dated to the Middle Triassic around 238 to 240 million years ago, and they had achieved a worldwide distribution by the Early Jurassic. Most rhynchocephalians belong to the group Sphenodontia ('wedge-teeth'). Their closest living relatives are lizards and snakes in the order Squamata, with the two orders being grouped together in the superorder Lepidosauria. Many of the niches occupied by lizards today were held by sphenodontians during the Triassic and Jurassic, although lizard diversity began to overtake sphenodontian diversity in the Cretaceous, and they had disappeared almost entirely by the beginning of the Cenozoic. While the modern tuat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gephyrosaurus
''Gephyrosaurus'' is a genus of early rhynchocephalian first described and named in 1980 by Susan E. Evans. They are distantly related to the extant ''Sphenodon'' (tuatara of New Zealand) with which they shared a number of skeletal features including a large tooth row along the side of the palatine bone (part of the palate) and posterior process of the dentary bone (part of the lower jaw). The type species, ''G. bridensis'', lived during Early Jurassic in Wales, UK. Whiteside & Duffin (2017) described the second species, ''G. evansae'', known from a partial maxilla recovered from Late Triassic (Rhaetian) fissure fills in Carboniferous Limestone in Somerset. They and other potential gephyrosaurids are the only rhynchocephalians to lie outside Sphenodontia in modern definitions of the group, and have been found to be more closely related to squamates in some phylogenetic analyses. Anatomical Description Limbs Observation of the skeletal elements of ''Gephyrosaurus bridensis'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pristidactylus
''Pristidactylus'' is a genus of lizards from Chile and Argentina. Species ''Pristidactylus'' contains ten recognized species: *'' Pristidactylus achalensis'' (Gallardo, 1964) - Argentine anole *'' Pristidactylus alvaroi'' ( Donoso-Barros, 1975) *'' Pristidactylus araucanus'' (Gallardo, 1964) *'' Pristidactylus casuhatiensis'' (Gallardo, 1968) - Casuhatien anole *'' Pristidactylus fasciatus'' (d'Orbigny & Bibron, 1837) - D'Orbigny's banded anole *'' Pristidactylus nigroiugulus'' Cei, Scolaro & Videla, 2001 *'' Pristidactylus scapulatus'' ( Burmeister, 1861) - Burmeister's anole *'' Pristidactylus torquatus'' (Philippi, 1861) *'' Pristidactylus valeriae'' (Donoso-Barros, 1966) *'' Pristidactylus volcanensis'' Lamborot & Díaz, 1987 ''Nota bene'': A binomial authority In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diphydontosaurus
''Diphydontosaurus'' is an extinct genus of rhynchocephalian reptile from the Late Triassic of England and Italy. This small animal was related to the living tuatara (''Sphenodon''). It may have grown to a length of . It is more derived than ''Gephyrosaurus'', yet more primitive than ''Planocephalosaurus'', and shares traits with both of them. Description ''Diphydontosaurus'' was a small sphenodontian, measuring up to long. It had long, sharp claws to help it catch its prey, and peg-like piercing teeth to help it eat insects. These features are shared with the other primitive rhynchocephalians ''Gephyrosaurus'' and ''Planocephalosaurus''. Classification ''Diphydontosaurus'' is known from many mostly complete specimens, which means that its classification as a rhynchocephalian is quite certain. In an analysis by Oliver Rahut and colleagues in 2012, it was found that ''Diphydontosaurus'' is the second most basal rhynchocephalian, after ''Gephyrosaurus'', and the most primitive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
George Gaylord Simpson
George Gaylord Simpson (June 16, 1902 – October 6, 1984) was an American paleontologist. Simpson was perhaps the most influential paleontologist of the twentieth century, and a major participant in the Modern synthesis (20th century), modern synthesis, contributing ''Tempo and Mode in Evolution'' (1944), ''The Meaning of Evolution'' (1949) and ''The Major Features of Evolution'' (1953). He was an expert on extinct mammals and their intercontinental migrations. Simpson was extraordinarily knowledgeable about Mesozoic fossil mammals and fossil mammals of North and South America. He anticipated such concepts as punctuated equilibrium (in ''Tempo and Mode'') and dispelled the myth that the evolution of the horse was a linear process culminating in the modern ''Equus caballus''. He coined the word ''wikt:hypodigm, hypodigm'' in 1940, and published extensively on the Taxonomy (biology), taxonomy of fossil and extant mammals. Simpson was influentially, and incorrectly, opposed to Alf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphenovipera
''Sphenovipera jimmysjoyi'' is an extinct species of sphenodontian dated from the Middle Jurassic. If was discovered in the lower part of the La Boca Formation located in Tamaulipas, Mexico. Only the lower jaw of this organism has been discovered and studied. It is possibly the only species of rhynchocephalian yet discovered to show evidence of venom delivery. Etymology ''Sphenovipera'' was named by Reynoso in 2005. The name alludes to sphenodontians via ''Spheno-'' and ''-vipera'' is Latin for "venomous snake." Venom delivery The mandible of ''Sphenovipera jimmysjoyi'' has several characteristics indicative of venom delivery. This includes large curved fangs with grooves seen in other animals that use low-pressure venom delivery, such as colubrid snakes Snakes are elongated, limbless, carnivorous reptiles of the suborder Serpentes . Like all other squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales. Many species of snakes have skulls ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acrodont
Acrodonty (from Greek ''akros'' 'highest' + ''dont'' 'tooth') is an anatomical placement of the teeth at the summit of the alveolar ridge of the jaw, without sockets, characteristic of bony fish. Functionally, acrodont tooth implantation may be related to strong bite force. Acrodonty in the Animal Kingdom Squamata: Within squamate reptiles, acrodont tooth implantation is best known in Acrodonta and some species of amphisbaenians, though some snakes are also referred to as being acrodont. Acrodonta is unique in that the name of the clade is based upon this trait. Most other squamate reptiles have pleurodont dentition, though some snakes are occasionally described as having acrodont dentition. Rhynchocephalia: Acrodont tooth implantation is common within Rhynchocephalia, including ''Sphenodon''. Amphibia: Acrodont tooth implantation also present in some frogs and the temnospondyl ''Microposaurus ''Microposaurus'' (meaning "small eyed lizard"; from Greek , "small" + , "face" o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Planocephalosaurus
''Planocephalosaurus'' is an extinct genus of rhynchocephalian. Fossils of the genus were found in the Tecovas Formation of Texas and the Magnesian Conglomerate of England. ''Planocephalosaurus'' was one of the first sphenodonts and bore a strong resemblance to the extant tuatara, albeit much smaller, at only in length. The creature is presumed to have fed on large invertebrates and small vertebrates. Dentition ''Planocephalosaurus'' exhibits very interesting dentition. Initially, it was believed to have been attached to the bone via acrodont tooth implantation, however, after this specimen was exposed to X-radiography it was determined that this animal has a combination of different tooth implantation types. Similar to another rhynchocephalian, ''Diphydontosaurus'', it possesses acrodont teeth in the posterior portion of the jaw, and pleurodont dentition in the anterior portion. ''Planocephalosauruss teeth were also fused with the cartilage, unlike its only extant Extant is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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