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Dendromaia
''Dendromaia'' is an extinct genus of Varanopidae, varanopid from the Carboniferous of Nova Scotia. It contains a single species, ''Dendromaia unamakiensis''. ''Dendromaia'' is the oldest known varanopid, likely the oldest known synapsid, and the only member of the family Varanopidae to be discovered in Nova Scotia. Known from a large partial skeleton preserved with its tail wrapped around a much smaller partial skeleton, ''Dendromaia'' may also represent the oldest known occurrence of parental care in the fossil record. While the larger skeleton possessed certain mycterosaurine-like features, the smaller skeleton resembled basal varanopids such as ''Archaeovenator'' and ''Pyozia'', creating uncertainty over whether characteristics at the base of Varanopidae have legitimate Phylogenetics, phylogenetic significance or instead reflect the immaturity of basal varanopid specimens. Discovery ''Dendromaia unamakiensis'' is known from a slab and counterslab containing two skeletons. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hillary Maddin
Hillary Catherine Maddin is a Canadians, Canadian Paleontology, paleontologist and Developmental biology, developmental biologist known for her work on development in extinct and extant amphibians. She is currently an associate professor in the Department of Earth Sciences at Carleton University. Academic and professional background Maddin obtained her B.Sc. in biology from the University of Toronto (1999-2004). She went on to also complete her M.Sc. degree at the University of Toronto (2004-2006) researching Caseidae, caseid synapsids under the supervision of Robert R. Reisz, Robert Reisz, followed by a Ph.D. degree (2006-2011) exploring the morphology and evolution of caecilians at the University of Calgary under the supervision of Anthony Russell and Jason Anderson. Maddin was awarded the highly competitive NSERC postdoctoral fellowship, which she used to fund a position at the Museum of Comparative Zoology and Harvard University in Cambridge, Massachusetts, Cambridge, MA (2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Varanopidae
Varanopidae is an extinct family of amniotes that resembled monitor lizards and may have filled a similar niche, hence the name. Typically, they are considered synapsids that evolved from an ''Archaeothyris''-like synapsid in the Late Carboniferous. However, some recent studies have recovered them being taxonomically closer to diapsid reptiles. A varanopid from the latest Middle Permian ''Pristerognathus'' Assemblage Zone is the youngest known varanopid and the last member of the "pelycosaur" group of synapsids. Description No known varanopids developed a sail like ''Dimetrodon''. The length of known varanopids, including the tail, varies from . Varanopids already showed some advanced characteristics of true pelycosaurs such as their deep, narrow, elongated skulls. Their jaws were long and their teeth were sharp. However, they were still primitive by mammalian standards. They had long tails, lizard-like bodies, and thin legs. The varanopids were mostly carnivorous, but as they ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moscovian (Carboniferous)
The Moscovian is in the International Commission on Stratigraphy, ICS geologic timescale a stage (stratigraphy), stage or age (geology), age in the Pennsylvanian (geology), Pennsylvanian, the youngest system (stratigraphy), subsystem of the Carboniferous. The Moscovian age lasted from to Megaannum, Ma, is preceded by the Bashkirian and is followed by the Kasimovian. The Moscovian overlaps with the European regional Westphalian (stage), Westphalian stage and the North American Atokan and Desmoinesian stages. Name and definition The Moscovian Stage was introduced by Sergei Nikitin (geologist), Sergei Nikitin (1850 - 1909) in 1890, using brachiopods in the Moscow Basin of European Russia. Nikitin named the stage after Moscow, then a major city and now the capital of Russia. The base of the Moscovian is close to the first appearances of the conodonts ''Declinognathodus donetzianus'' and ''Idiognathoides postsulcatus'' or otherwise the fusulinid ''Aljutovella aljutovica''. Because th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miꞌkmaq
The Mi'kmaq (also ''Mi'gmaq'', ''Lnu'', ''Miꞌkmaw'' or ''Miꞌgmaw''; ; ) are a First Nations people of the Northeastern Woodlands, indigenous to the areas of Canada's Atlantic Provinces and the Gaspé Peninsula of Quebec as well as the northeastern region of Maine. The traditional national territory of the Mi'kmaq is named Miꞌkmaꞌki (or Miꞌgmaꞌgi). There are 170,000 Mi'kmaq people in the region, (including 18,044 members in the recently formed Qalipu First Nation in Newfoundland.) Nearly 11,000 members speak Miꞌkmaq, an Eastern Algonquian language. Once written in Miꞌkmaw hieroglyphic writing, it is now written using most letters of the Latin alphabet. The Mi'kmaq, Maliseet, and Pasamaquoddy nations signed a series of treaties known as the Covenant Chain of Peace and Friendship Treaties with the British Crown throughout the eighteenth century; the first was signed in 1725, and the last in 1779. The Miꞌkmaq maintain that they did not cede or give up their ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Femur
The femur (; ), or thigh bone, is the proximal bone of the hindlimb in tetrapod vertebrates. The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates with the tibia (shinbone) and patella (kneecap), forming the knee joint. By most measures the two (left and right) femurs are the strongest bones of the body, and in humans, the largest and thickest. Structure The femur is the only bone in the upper leg. The two femurs converge medially toward the knees, where they articulate with the proximal ends of the tibiae. The angle of convergence of the femora is a major factor in determining the femoral-tibial angle. Human females have thicker pelvic bones, causing their femora to converge more than in males. In the condition ''genu valgum'' (knock knee) the femurs converge so much that the knees touch one another. The opposite extreme is ''genu varum'' (bow-leggedness). In the general populatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pelvis
The pelvis (plural pelves or pelvises) is the lower part of the trunk, between the abdomen and the thighs (sometimes also called pelvic region), together with its embedded skeleton (sometimes also called bony pelvis, or pelvic skeleton). The pelvic region of the trunk includes the bony pelvis, the pelvic cavity (the space enclosed by the bony pelvis), the pelvic floor, below the pelvic cavity, and the perineum, below the pelvic floor. The pelvic skeleton is formed in the area of the back, by the sacrum and the coccyx and anteriorly and to the left and right sides, by a pair of hip bones. The two hip bones connect the spine with the lower limbs. They are attached to the sacrum posteriorly, connected to each other anteriorly, and joined with the two femurs at the hip joints. The gap enclosed by the bony pelvis, called the pelvic cavity, is the section of the body underneath the abdomen and mainly consists of the reproductive organs (sex organs) and the rectum, while the pelvic f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osteoderm
Osteoderms are bony deposits forming scales, plates, or other structures based in the dermis. Osteoderms are found in many groups of extant and extinct reptiles and amphibians, including lizards, crocodilians, frogs, temnospondyls (extinct amphibians), various groups of dinosaurs (most notably ankylosaurs and stegosaurians), phytosaurs, aetosaurs, placodonts, and hupehsuchians (marine reptiles with possible ichthyosaur affinities). Osteoderms are uncommon in mammals, although they have occurred in many xenarthrans (armadillos and the extinct glyptodonts and mylodontid and scelidotheriid ground sloths). The heavy, bony osteoderms have evolved independently in many different lineages. The armadillo osteoderm is believed to develop in subcutaneous dermal tissues. These varied structures should be thought of as anatomical analogues, not homologues, and do not necessarily indicate monophyly. The structures are however derived from scutes, common to all classes of amniotes and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastralium
Gastralia (singular gastralium) are dermal bones found in the ventral body wall of modern crocodilians and tuatara, and many prehistoric tetrapods. They are found between the sternum and pelvis, and do not articulate with the vertebrae. In these reptiles, gastralia provide support for the abdomen and attachment sites for abdominal muscles. The possession of gastralia may be ancestral for Tetrapoda and were possibly derived from the ventral scales found in animals like rhipidistians, labyrinthodonts, and ''Acanthostega'', and may be related to ventral elements of turtle plastrons. Similar, but not homologous cartilagenous elements, are found in the ventral body walls of lizards and anurans. These structures have been referred to as inscriptional ribs, based on their alleged association with the inscriptiones tendinae (the tendons that form the six pack in humans). However, the terminology for these gastral-like structures remains confused. Both types, along with sternal rib ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heleosaurus
''Heleosaurus scholtzi'' is an extinct species of basal synapsids, known as pelycosaurs, in the family of Varanopidae during the middle Permian.Reisz, R. R. & Modesto, S. P. 2007. ''Heleosaurus scholtzi'' from the Permian of South Africa: a varanopid synapsid, not a diapsid reptile. ''Journal of Vertebrate Paleontology'' 27 (3): 734-739. At first ''H. scholtzi'' was mistakenly classified as a diapsid. Members of this family were carnivorous and had dermal armor, and somewhat resembled monitor lizards. This family was the most geologically long lived, widespread, and diverse group of early amniotes. To date only two fossils have been found in the rocks of South Africa.Broom, R. "On Some New Fossil Reptiles from the Karroo Beds of Victoria West, South Africa." ''Transactions of the South African Philosophical Society'' 18 (1907): 31-42. Taylor and Francis Online. Web. Botha-Brink, Jennifer. "A Mixed-Age Classed 'Pelycosaur' Aggregation from South Africa: Earliest Evidence of Parental ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mycterosaurus
''Mycterosaurus'' (Greek as mykter/mykteros meaning nose/snout, sauros meaning “lizard”) is an extinct genus of synapsids belonging to the family Varanopidae. It is classified in the varanopid subfamily Mycterosaurinae. ''Mycterosaurus'' is the most primitive member of its family, existing from 290.1 to 272.5 MYA, known to Texas and Oklahoma. It lacks some features that its advanced relatives have. ''Mycterosaurus'' is a relatively small carnivore, estimated to be around 60 cm (23 inches) long with synonyms of ''Eumatthevia bolli'', and possibly ''Basicranodon fortsillensis''. Restored, ''Mycterosaurus'' appears spindly and grotesque in contrast to the majority of "pelycosaurs" in its proportions and especially unlike edaphosaurs, which are commonly stocky in build. The number of valid ''Mycterosaurus'' species have varied over the years, with a total of two classifications of ''Mycterosaurus longiceps'' and ''Mycterosaurus smithae.'' However, recent analysis has l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thoracic Vertebrae
In vertebrates, thoracic vertebrae compose the middle segment of the vertebral column, between the cervical vertebrae and the lumbar vertebrae. In humans, there are twelve thoracic vertebra (anatomy), vertebrae and they are intermediate in size between the cervical and lumbar vertebrae; they increase in size going towards the lumbar vertebrae, with the lower ones being much larger than the upper. They are distinguished by the presence of Zygapophysial joint, facets on the sides of the bodies for Articulation (anatomy), articulation with the head of rib, heads of the ribs, as well as facets on the transverse processes of all, except the eleventh and twelfth, for articulation with the tubercle (rib), tubercles of the ribs. By convention, the human thoracic vertebrae are numbered T1–T12, with the first one (T1) located closest to the skull and the others going down the spine toward the lumbar region. General characteristics These are the general characteristics of the second throu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taxon
In biology, a taxon (back-formation from ''taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and given a particular ranking, especially if and when it is accepted or becomes established. It is very common, however, for taxonomists to remain at odds over what belongs to a taxon and the criteria used for inclusion. If a taxon is given a formal scientific name, its use is then governed by one of the nomenclature codes specifying which scientific name is correct for a particular grouping. Initial attempts at classifying and ordering organisms (plants and animals) were set forth in Carl Linnaeus's Linnaean taxonomy, system in ''Systema Naturae'', 10th edition (1758), as well as an unpublished work by Bernard de Jussieu, Bernard and Antoine Laurent de Jussieu. The idea of a unit-based system of biological classification was first mad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
