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Stereosternum
''Stereosternum tumidum'' (meaning "rigid chest") (Stereos, Greek: “solid, firm”; Sternon, Greek: “chest, breastbone”) is an extinct genus of mesosaur marine reptile from the Early Permian of Brazil and also the Great Karoo Basin of South Africa.Oelofsen, B. W. and D. C. Araujo. "Mesosaurus Tenuidens and Stereosternum Tumidum from the Permian Gondwana of Both Southern Africa and South America." South African Journal of Science, vol. 83, no. 6, 01 June 1987, pp. 370-372. The taxon mesosaur is a monophyletic group containing ''Brazilosaurus sanpauloensis'' and '' Mesosaurus tenuidens''. For most of the 20th century, information of ''Stereosternum'' was reported as ''Mesosaurus''. Unlike previous interpretations of Mesosaurs as filter feeding animals, later studies have shown that these animals were very much active aquatic predators. ''Stereosternum'' and ''Mesosaurus'' are the oldest reported reptile species to have had a range spanning two present-day continents, then joi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stereosternum Brasilianum
''Stereosternum tumidum'' (meaning "rigid chest") (Stereos, Greek: “solid, firm”; Sternon, Greek: “chest, breastbone”) is an extinct genus of mesosaur marine reptile from the Early Permian of Brazil and also the Great Karoo Basin of South Africa.Oelofsen, B. W. and D. C. Araujo. "Mesosaurus Tenuidens and Stereosternum Tumidum from the Permian Gondwana of Both Southern Africa and South America." South African Journal of Science, vol. 83, no. 6, 01 June 1987, pp. 370-372. The taxon mesosaur is a monophyletic group containing ''Brazilosaurus sanpauloensis'' and ''Mesosaurus tenuidens''. For most of the 20th century, information of ''Stereosternum'' was reported as ''Mesosaurus''. Unlike previous interpretations of Mesosaurs as filter feeding animals, later studies have shown that these animals were very much active aquatic predators. ''Stereosternum'' and ''Mesosaurus'' are the oldest reported reptile species to have had a range spanning two present-day continents, then joine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stereosternum
''Stereosternum tumidum'' (meaning "rigid chest") (Stereos, Greek: “solid, firm”; Sternon, Greek: “chest, breastbone”) is an extinct genus of mesosaur marine reptile from the Early Permian of Brazil and also the Great Karoo Basin of South Africa.Oelofsen, B. W. and D. C. Araujo. "Mesosaurus Tenuidens and Stereosternum Tumidum from the Permian Gondwana of Both Southern Africa and South America." South African Journal of Science, vol. 83, no. 6, 01 June 1987, pp. 370-372. The taxon mesosaur is a monophyletic group containing ''Brazilosaurus sanpauloensis'' and '' Mesosaurus tenuidens''. For most of the 20th century, information of ''Stereosternum'' was reported as ''Mesosaurus''. Unlike previous interpretations of Mesosaurs as filter feeding animals, later studies have shown that these animals were very much active aquatic predators. ''Stereosternum'' and ''Mesosaurus'' are the oldest reported reptile species to have had a range spanning two present-day continents, then joi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesosaurus
''Mesosaurus'' (meaning "middle lizard") is an extinct genus of reptile from the Early Permian of southern Africa and South America. Along with it, the genera '' Brazilosaurus'' and ''Stereosternum'', it is a member of the family Mesosauridae and the order Mesosauria. ''Mesosaurus'' was long thought to have been one of the first marine reptiles, although new data suggests that at least those of Uruguay inhabited a hypersaline water body, rather than a typical marine environment. In any case, it had many adaptations to a fully aquatic lifestyle. It is usually considered to have been anapsid, although Friedrich von Huene considered it to be a synapsid, and this hypothesis has been revived recently. Discovery and naming The holotype of ''M. tenuidens'', MNHN 1865-77, is nicknamed the "Griqua ''Mesosaurus''" and it was found in a Griqua hut in South Africa, likely in Kimberley, Northern Cape around 1830 and was being used as a pot lid. The circumstances of its discovery and how i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesosaurus Tenuidens
''Mesosaurus'' (meaning "middle lizard") is an extinct genus of reptile from the Early Permian of southern Africa and South America. Along with it, the genera '' Brazilosaurus'' and ''Stereosternum'', it is a member of the family Mesosauridae and the order Mesosauria. ''Mesosaurus'' was long thought to have been one of the first marine reptiles, although new data suggests that at least those of Uruguay inhabited a hypersaline water body, rather than a typical marine environment. In any case, it had many adaptations to a fully aquatic lifestyle. It is usually considered to have been anapsid, although Friedrich von Huene considered it to be a synapsid, and this hypothesis has been revived recently. Discovery and naming The holotype of ''M. tenuidens'', MNHN 1865-77, is nicknamed the "Griqua ''Mesosaurus''" and it was found in a Griqua hut in South Africa, likely in Kimberley, Northern Cape around 1830 and was being used as a pot lid. The circumstances of its discovery and how i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesosaur
Mesosaurs ("middle lizards") were a group of small aquatic reptiles that lived during the early Permian period, roughly 299 to 270 million years ago. Mesosaurs were the first known aquatic reptiles, having apparently returned to an aquatic lifestyle from more terrestrial ancestors. It is uncertain which and how many terrestrial traits these ancestors displayed; recent research cannot establish with confidence if the first amniotes were fully terrestrial, or only amphibious. Most authors consider mesosaurs to have been aquatic, although adult animals may have been amphibious, rather than completely aquatic, as indicated by their moderate skeletal adaptations to a semiaquatic lifestyle.Pablo Nuñez Demarco et al. Was Mesosaurus a Fully Aquatic Reptile? Front. Ecol. Evol, published online July 27, 2018; doi: 10.3389/fevo.2018.00109 Similarly, their affinities are uncertain; they may have been among the most basal sauropsids or among the most basal parareptiles (in the case of whic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cisuralian
The Cisuralian is the first Series (stratigraphy), series/Epoch (geology), epoch of the Permian. The Cisuralian was preceded by the Pennsylvanian (geology), Pennsylvanian and followed by the Guadalupian. The Cisuralian Epoch is named after the western slopes of the Ural Mountains in Russia and Kazakhstan and dates between 298.9 ± 0.15 – 272.3 ± 0.5 Mya. The Cisuralian is often synonymous with the informal terms early Permian or lower Permian. It corresponds approximately with the Wolfcampian in southwestern North America. The series saw the appearance of beetles and Fly, flies and was a relatively stable warming period of about 21 million years. Name and background The Cisuralian is the first series or epoch of the Permian. The Cisuralian was preceded by the last Pennsylvanian epoch (Gzhelian) and is followed by the Permian Guadalupian Epoch. The name "Cisuralian" was proposed in 1982, and approved by the International Subcommission on Permian Stratigraphy in 1996. The Ci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pachyosteosclerosis
Pachyosteosclerosis is a combination of thickening (pachyostosis) and densification (osteosclerosis) of bones. It makes bones more heavy, but also more fragile. The condition often occurs in aquatic vertebrates, especially those living in shallow waters,Houssaye, A. (2009). "Pachyostosis" in aquatic amniotes: a review. Integrative Zoology 4(4): 325-340. creating ballast as an adaptation for maintaining neutral buoyancy and horizontal trim. It is in no way pathological. To resist bend, it frequently is found especially in ventral bones, whereas concentration near the lungs helps in maintaining trim. Examples of animals showing pachyosteosclerosis are seacows (dugongs and manatees), the extinct Plesiosauria and Mesosauria and extinct aquatic sloths.Amson, E., C. de Muizon, M. Laurin, C. Argot and V. de Buffrenil (2014). Gradual adaptation of bone structure to aquatic lifestyle in extinct sloths from Peru. Proceedings of the Royal Society B-Biological Sciences 281. See also * Pachyo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caudal Vertebrae
The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic irregular bone whose complex structure is composed primarily of bone, and secondarily of hyaline cartilage. They show variation in the proportion contributed by these two tissue types; such variations correlate on one hand with the cerebral/caudal rank (i.e., location within the backbone), and on the other with phylogenetic differences among the vertebrate taxa. The basic configuration of a vertebra varies, but the bone is its ''body'', with the central part of the body constituting the ''centrum''. The upper (closer to) and lower (further from), respectively, the cranium and its central nervous system surfaces of the vertebra body support attachment to the intervertebral discs. The posterior part of a vertebra forms a vertebral arch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Humerus
The humerus (; ) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius and ulna, and consists of three sections. The humeral upper extremity consists of a rounded head, a narrow neck, and two short processes (tubercles, sometimes called tuberosities). The body is cylindrical in its upper portion, and more prismatic below. The lower extremity consists of 2 epicondyles, 2 processes (trochlea & capitulum), and 3 fossae (radial fossa, coronoid fossa, and olecranon fossa). As well as its true anatomical neck, the constriction below the greater and lesser tubercles of the humerus is referred to as its surgical neck due to its tendency to fracture, thus often becoming the focus of surgeons. Etymology The word "humerus" is derived from la, humerus, umerus meaning upper arm, shoulder, and is linguistically related to Gothic ''ams'' shoulder and Greek ''ōmos''. Structure Upper extremity The upper or pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phalangeal Formula
The phalanges (singular: ''phalanx'' ) are digital bones in the hands and feet of most vertebrates. In primates, the thumbs and big toes have two phalanges while the other digits have three phalanges. The phalanges are classed as long bones. Structure The phalanges are the bones that make up the fingers of the hand and the toes of the foot. There are 56 phalanges in the human body, with fourteen on each hand and foot. Three phalanges are present on each finger and toe, with the exception of the thumb and large toe, which possess only two. The middle and far phalanges of the fifth toes are often fused together (symphalangism). The phalanges of the hand are commonly known as the finger bones. The phalanges of the foot differ from the hand in that they are often shorter and more compressed, especially in the proximal phalanges, those closest to the torso. A phalanx is named according to whether it is proximal, middle, or distal and its associated finger or toe. The proximal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
