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Pricemys
Podocnemididae is a family of pleurodire (side-necked) turtles, once widely distributed. Most of its 20 genera and 30 species are now extinct. Seven of its eight surviving species are native to South America: the genus ''Peltocephalus'', with only one species (''P. dumerilianus'', the big-headed Amazon River turtle); and the genus ''Podocnemis'', with six living species of South American side-necked river turtles. There is also one genus native to Madagascar: ''Erymnochelys'', the Madagascan big-headed turtle, whose single species ''E. madagascariensis''. Like other pleurodire turtles, podocs have a "side-necked" defensive posture, turning the head sideways to hide it under the shell. Another characteristic of pleurodires is that the pelvis is fused to the shell which prevents pelvic motion, making it difficult to walk on land. Podocnemididae turtles live in aquatic environments and have shells streamlined to aid in swimming. Taxonomy and systematics According to Ferreira et ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stupendemys
''Stupendemys'' is an extinct genus of freshwater side-necked turtle, belonging to the family Podocnemididae. It is the largest freshwater turtle known to have existed, with a carapace over 2 meters long. Its fossils have been found in northern South America, in rocks dating from the Middle Miocene to the very start of the Pliocene, about 13 to 5 million years ago. Male specimens are known to have possessed bony horns growing from the front edges of the shell and the discovery of the fossil of a young adult shows that the carapace of these turtles flattens with age. A fossil skull described in 2021 indicates that ''Stupendemys'' was a generalist feeder. History and naming ''Stupendemys'' was first named in 1976 by Roger C. Wood based on specimen MCNC-244, the medial portion of a large sized carapace with associated left femur, scapulacoracoid and a cervical vertebra. Wood also described several other specimens he referred to ''Stupendemys'', which includes MCZ(P)-4376. This s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the Latin word for the white limestone known as chalk. The chalk of northern France and the white cliffs of south-eastern England date from the Cretaceous Period. Climate During the Late Cretaceous, the climate was warmer than present, although throughout the period a cooling trend is evident. The tropics became restricted to equatorial regions and northern latitudes experienced markedly more seasonal climatic conditions. Geography Due to plate tectonics, the Americas were gradually moving westward, causing the Atlantic Ocean to expand. The Western Interior Seaway divided North America into eastern and western halves; Appalachia and Laramidia. India maintained a northward course towards Asia. In the Southern Hemisphere, Australia an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pelomedusidae
:''Alternatively, "Pelomedusidae" may refer to the Pelomedusoidea. See below for details.'' Pelomedusidae is a family of freshwater turtles endemic to sub-Saharan Africa, including Madagascar, São Tomé, and the Seychelles(Although this pop. may have been introduced by humans). They range in size from in carapace length, and are generally roundish in shape. They are unable to fully withdraw their heads into their shells, instead drawing them to the side and folding them beneath the upper edge of their shells, hence are called African side-necked turtles. The family contains two living genera. They are distinguished from their closest relatives by a hinge in the front section of the plastron.Obst, Fritz Jürgen (1998): elomedusinae ''In:'' Cogger, H.G., & Zweifel, R.G. (eds.): ''Encyclopedia of Reptiles and Amphibians'': 112-113. San Diego: Academic Press. . Pelomedusidae spends most of its time in the mud at the bottom of rivers or shallow lakes, where they eat invertebrates ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Romualdo Formation
The Romualdo Formation is a geologic Konservat-Lagerstätte in northeastern Brazil's Araripe Basin where the states of Pernambuco, Piauí and Ceará come together. The geological formation, previously designated as the Romualdo Member of the Santana Formation, named after the village of Santana do Cariri, lies at the base of the Araripe Plateau. It was discovered by Johann Baptist von Spix in 1819. The strata were deposited during the Aptian stage of the Early Cretaceous in a lacustrine rift basin with shallow marine incursions of the proto-Atlantic. At that time, the South Atlantic was opening up in a long narrow shallow sea. The Romualdo Formation earns the designation of Lagerstätte due to an exceedingly well preserved and diverse fossil faunal assemblage. Some 25 species of fossil fishes are often found with stomach contents preserved, enabling paleontologists to study predator–prey relationships in this ecosystem. There are also fine examples of pterosaurs, reptiles a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stem-group
In phylogenetics, the crown group or crown assemblage is a collection of species composed of the living representatives of the collection, the most recent common ancestor of the collection, and all descendants of the most recent common ancestor. It is thus a way of defining a clade, a group consisting of a species and all its extant or extinct descendants. For example, Neornithes (birds) can be defined as a crown group, which includes the most recent common ancestor of all modern birds, and all of its extant or extinct descendants. The concept was developed by Willi Hennig, the formulator of phylogenetic systematics, as a way of classifying living organisms relative to their extinct relatives in his "Die Stammesgeschichte der Insekten", and the "crown" and "stem" group terminology was coined by R. P. S. Jefferies in 1979. Though formulated in the 1970s, the term was not commonly used until its reintroduction in 2000 by Graham Budd and Sören Jensen. Contents of the crown gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Big-headed Amazon River Turtle
The big-headed Amazon River turtle (''Peltocephalus dumerilianus''),"''Peltocephalus dumerilianus'' " The Reptile Database. also known as the big-headed sideneck, is a of in the . The species is |
Madagascan Big-headed Turtle
The Madagascan big-headed turtle (''Erymnochelys madagascariensis'') is a turtle native to the waters of permanent slow moving rivers and lakes in western Madagascar. These turtles are critically endangered and have been evaluated to be the most endangered turtle in the world by a 2018 review. Despite their vulnerability to extinction, they are commonly eaten for food and they are still commonly shipped from Madagascar to Asia to help meet the demand of Asia's traditional medicine market. A captive breeding program has also been started to prevent the species from becoming extinct. The Turtle Conservation Fund (TCF) intends to raise US$5.6 million to cover a five-year 'Global Action Plan' which includes captive breeding and reintroduction projects, trade monitoring, new rescue centers, local conservation plans, and educational programs. Description The Madagascan big-headed turtle is one of the most endangered turtles in the world, and is also included in the Turtle Conservatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monotypic
In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispecific" or "monospecific" is sometimes preferred. In botanical nomenclature, a monotypic genus is a genus in the special case where a genus and a single species are simultaneously described. In contrast, an oligotypic taxon contains more than one but only a very few subordinate taxa. Examples Just as the term ''monotypic'' is used to describe a taxon including only one subdivision, the contained taxon can also be referred to as monotypic within the higher-level taxon, e.g. a genus monotypic within a family. Some examples of monotypic groups are: Plants * In the order Amborellales, there is only one family, Amborellaceae and there is only one genus, '' Amborella'', and in this genus there is only one species, namely ''Amborella trichopoda. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genera
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. ''Panthera leo'' (lion) and ''Panthera onca'' (jaguar) are two species within the genus ''Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants of an ancestral taxon are grouped together (i.e. phylogenetic analysis should clearly demons ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quadrate Bone
The quadrate bone is a skull bone in most tetrapods, including amphibians, sauropsids (reptiles, birds), and early synapsids. In most tetrapods, the quadrate bone connects to the quadratojugal and squamosal bones in the skull, and forms upper part of the jaw joint. The lower jaw articulates at the articular bone, located at the rear end of the lower jaw. The quadrate bone forms the lower jaw articulation in all classes except mammals. Evolutionarily, it is derived from the hindmost part of the primitive cartilaginous upper jaw. Function in reptiles In certain extinct reptiles, the variation and stability of the morphology of the quadrate bone has helped paleontologists in the species-level taxonomy and identification of mosasaur squamates and spinosaurine dinosaurs. In some lizards and dinosaurs, the quadrate is articulated at both ends and movable. In snakes, the quadrate bone has become elongated and very mobile, and contributes greatly to their ability to swallow very l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pterygoid Bone
The pterygoid is a paired bone forming part of the palate of many vertebrates Vertebrates () comprise all animal taxa within the subphylum Vertebrata () (chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, with c ..., behind the palatine bones. It is a flat and thin lamina, united to the medial side of the pterygoid process of the sphenoid bone, and to the perpendicular lamina of the palatine bone. Bones of the head and neck {{musculoskeletal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
