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Nectosaurus
''Nectosaurus'' is a genus of thalattosaur (marine diapsid reptiles) which lived during the Late Triassic in what is now California. The type and only known species, ''Nectosaurus halius'', was found in the Hosselkus Limestone and described by John C. Merriam in 1905, making it one of the first thalattosaurians known (along with '' Thalattosaurus'').Sepkoski, J.J. (2002). "A compendium of fossil marine animal genera". ''Bulletins of American Paleontology'' 363: 1-560. Discovery ''Nectosaurus'' is known from fragmentary remains. The holotype, UCMP 9124, is an incomplete skeleton including vertebrae, a humerus, coracoid, ulna, radius, and partial skull and mandibles. Many isolated bones from other localities were referred to the genus by Merriam in 1908. In addition, a partial skull from the same locality, UCMP 9120, was referred to the genus as ''Nectosaurus sp.'' in 1905. This specimen is much larger than any specimen of ''Nectosaurus halius'' but is otherwise simi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nectosaurus Skull
''Nectosaurus'' is a genus of thalattosaur (marine diapsid reptiles) which lived during the Late Triassic in what is now California. The type and only known species, ''Nectosaurus halius'', was found in the Hosselkus Limestone and described by John C. Merriam in 1905, making it one of the first thalattosaurians known (along with '' Thalattosaurus'').Sepkoski, J.J. (2002). "A compendium of fossil marine animal genera". ''Bulletins of American Paleontology'' 363: 1-560. Discovery ''Nectosaurus'' is known from fragmentary remains. The holotype, UCMP 9124, is an incomplete skeleton including vertebrae, a humerus, coracoid, ulna, radius, and partial skull and mandibles. Many isolated bones from other localities were referred to the genus by Merriam in 1908. In addition, a partial skull from the same locality, UCMP 9120, was referred to the genus as ''Nectosaurus sp.'' in 1905. This specimen is much larger than any specimen of ''Nectosaurus halius'' but is otherwise similar to se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thalattosaur
Thalattosauria (Attic Greek, Greek for "sea lizards") is an extinct Order (biology), order of prehistoric marine reptiles that lived in the middle to late Triassic period. Thalattosaurs were diverse in size and shape, and are divided into two superfamilies: Askeptosauroidea and Thalattosauroidea. Askeptosauroids were endemic to the Tethys Ocean, their fossils have been found in Europe and China, and they were likely semiaquatic fish eaters with straight snouts and decent terrestrial abilities. Thalattosauroids were more specialized for aquatic life and most had unusual downturned snouts and crushing dentition. Thalattosauroids lived along the coasts of both Panthalassa and the Tethys Ocean, and were most diverse in China and western North America. The largest species of thalattosaurs grew to over 4 meters (13 feet) in length, including a long, flattened tail utilized in underwater propulsion. Although thalattosaurs bore a superficial resemblance to lizards, their exact relation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thalattosaurs
Thalattosauria (Greek for "sea lizards") is an extinct order of prehistoric marine reptiles that lived in the middle to late Triassic period. Thalattosaurs were diverse in size and shape, and are divided into two superfamilies: Askeptosauroidea and Thalattosauroidea. Askeptosauroids were endemic to the Tethys Ocean, their fossils have been found in Europe and China, and they were likely semiaquatic fish eaters with straight snouts and decent terrestrial abilities. Thalattosauroids were more specialized for aquatic life and most had unusual downturned snouts and crushing dentition. Thalattosauroids lived along the coasts of both Panthalassa and the Tethys Ocean, and were most diverse in China and western North America. The largest species of thalattosaurs grew to over 4 meters (13 feet) in length, including a long, flattened tail utilized in underwater propulsion. Although thalattosaurs bore a superficial resemblance to lizards, their exact relationships are unresolved. They ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thalattosauroidea
Thalattosauroidea is a superfamily of thalattosaurs, a Triassic group of marine reptiles. It was named in 1904 by paleontologist John Campbell Merriam to include the genus '' Thalattosaurus'' from California. Thalattosauroids are one of two groups of Thalattosauria, the other being Askeptosauroidea. Thalattosauroids make up the "traditional" thalattosaurs with large downturned snouts, short necks, and long, paddle-like tails. Classification Thalattosauria includes North American genera such as ''Thalattosaurus'' and ''Nectosaurus'' as well as recently described Chinese forms such as ''Xinpusaurus''. A 1999 study of thalattosaurs, which established much of the currently accepted phylogeny of the group, referred to Thalattosauroidea as Thalattosauria, while calling the larger group Thalattosauriformes. More recent phylogenetic studies have come upon the same conclusions, but refer to the group as Thalattosauroidea in order to contrast it with another superfamily of thalattosaurs, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thalattosaurus
''Thalattosaurus'' (pronounced: , "tha-la-to-SORE-us") meaning "sea lizard," from the Attic Greek ' (), "sea," and ' (), "lizard," is an extinct genus of marine reptile in the family Thalattosauroidea. They were aquatic diapsids that are known exclusively from the Triassic period. It was a long shellfish-eating reptile with paddle-like limbs and a down-turned rostrum occurring in the Lower and Middle Triassic Sulphur Mountain Formation of British Columbia as well as the Upper Triassic Hosselkus Limestone of California. It has gained notoriety as a result of studies on general diapsid phylogeny. Although originally described as four distinct species by Merriam in 1905, one was proven to be ''T. alexandrae'' upon further inspection and another has a missing type specimen. Currently it is believed to include two known species; ''Thalattosaurus alexandrae'' and ''T. borealis''. Discovery and naming In the summer of 1903 Annie Alexander led an expedition with Miss Edna We ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hosselkus Limestone
The Hosselkus Limestone is an Upper Triassic fossiliferous marine micritic limestone formation that outcrops in Plumas and Shasta Counties, California. It is known for its invertebrate fauna, most notably the many species of shelled cephalopods. Geology The geologic column of the nearby Taylorsville region shows the Hosselkus Limestone as 140 ft thick and of Late Triassic (early Karnian) age. It is well exposed near the Cosmopolitan mine on the divide between the Genesee Valley and Hosselkus Creek. It has been recognized at numerous outcrops between Spanish Ranch and Prattville and northwestward beyond Pit River in the Klamath Mountains, and is considered to be younger than the Swearinger slates and older than the Trail beds. It contains numerous ''Arcestes'' and abundant pentagonal crinoid stems which indicate it is of Late Triassic age. Paleofauna Over 208 described species of invertebrates have been found in the Hosselkus Limestone and nearby Brock Mountain. These speci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xinpusaurus
''Xinpusaurus'' is an extinct genus of thalattosaur from the Late Triassic of Guanling in Guizhou, China. Several species have been named since 2000: the type species ''X. suni'' along with the species ''X. bamaolinensis'' and ''X. kohi''. A 2013 study proposed that all three species are synonymous with each other, in which case ''X. suni'' would be the only valid species, although a 2014 study argued that ''X. kohi'' was also valid. A fourth species, ''X. xingyiensis'', was described in 2016. Description ''Xinpusaurus'' is a thalattosaur, a group of triassic marine reptiles with long, paddle-like tails and short legs with independently movable digits. Specifically, it is a member of the group thalattosauroidea, which are characterized by their downturned premaxillae. ''Xinpusaurus'' had a short neck, a massive quadrate, and one of the few braincases preserved in thalattosaurs. The lower jaws of this genus show two different forms of dentary- surangular sutures, either a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Triassic
The Late Triassic is the third and final epoch (geology), epoch of the Triassic geologic time scale, Period in the geologic time scale, spanning the time between annum, Ma and Ma (million years ago). It is preceded by the Middle Triassic Epoch and followed by the Early Jurassic Epoch. The corresponding series (stratigraphy), series of rock beds is known as the Upper Triassic. The Late Triassic is divided into the Carnian, Norian and Rhaetian Geologic time scale, Ages. Many of the first dinosaurs evolved during the Late Triassic, including ''Plateosaurus'', ''Coelophysis'', and ''Eoraptor''. The Triassic–Jurassic extinction event began during this epoch and is one of the five major mass extinction events of the Earth. Etymology The Triassic was named in 1834 by Friedrich August von Namoh, Friedrich von Alberti, after a succession of three distinct rock layers (Greek meaning 'triad') that are widespread in southern Germany: the lower Buntsandstein (colourful sandstone'')'', t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hescheleria
''Hescheleria'' is an extinct genus of thalattosaurian marine reptile from the Middle Triassic (247.2 to 235 Ma) of Monte San Giorgio in Switzerland. It is represented by a single type species, ''H. ruebeli'', which was named in 1936. Description Like other thalattosaurs, ''Hescheleria'' has a slender lizard-like body with a long paddle-shaped tail. It is estimated to have grown to approximately 1 meter in length. The skull possesses an unusually-shaped snout, with sharply downturned premaxillae. This forms a toothy hook at almost a right angle to the rest of the jaw, with a large diastema A diastema (plural diastemata, from Greek διάστημα, space) is a space or gap between two teeth. Many species of mammals have diastemata as a normal feature, most commonly between the incisors and molars. More colloquially, the condition .... The mandible is considerably robust and is dotted with small sharp teeth, along with a pair of pointed conical projections towards the t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coronoid Process Of The Mandible
In human anatomy, the mandible's coronoid process (from Greek ''korōnē'', denoting something hooked) is a thin, triangular eminence, which is flattened from side to side and varies in shape and size. Its anterior border is convex and is continuous below with the anterior border of the ramus. Its ''posterior border'' is concave and forms the anterior boundary of the mandibular notch. The ''lateral surface'' is smooth, and affords insertion to the temporalis and masseter muscles. Its ''medial surface'' gives insertion to the temporalis, and presents a ridge which begins near the apex of the process and runs downward and forward to the inner side of the last molar tooth. Between this ridge and the anterior border is a grooved triangular area, the upper part of which gives attachment to the temporalis, the lower part to some fibers of the buccinator. Clinical significance Fractures of the mandible are common. However, coronoid process fractures are very rare. Isolated fractures o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rostrum (anatomy)
Rostrum (from Latin ', meaning ''beak'') is a term used in anatomy for a number of phylogenetically unrelated structures in different groups of animals. Invertebrates * In crustaceans, the rostrum is the forward extension of the carapace in front of the eyes. It is generally a rigid structure, but can be connected by a hinged joint, as seen in Leptostraca. * Among insects, the rostrum is the name for the piercing mouthparts of the order Hemiptera as well as those of the snow scorpionflies, among many others. The long snout of weevils is also called a rostrum. * Gastropod molluscs have a rostrum or proboscis. * Cephalopod molluscs have hard beak-like mouthparts referred to as the rostrum. File:Washington DC Zoo - Macrobrachium rosenbergii 6.jpg, Crustacean: the rostrum of the shrimp '' Macrobrachium rosenbergii'' is serrated along both edges. File:Gminatus australis with Beetle.jpg, Insect: assassin bug piercing its prey with its rostrum File:Architeuthis beak.jpg, Ceph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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