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Paraphysornis Model Vienna
''Paraphysornis'' is an extinct genus of giant flightless terror birds that inhabited Brazil during Late Oligocene or Early Miocene epochs. Although not the tallest phorusrhacid, ''Paraphysornis'' was a notably robust bird, having short and robust tarsal bones not suited for pursuit hunting. Discovery and naming The holotype (DGM-1418-R) and only known fossil was discovered by a mining company in the Taubaté Basin (São Paulo State) in a layer of bentonite clay, two or three meters below a layer of Pyrobitumen. These sediments belong to the Late Oligocene to Early Miocene Tremembé Formation. Excavation of the bones took several months between 1977 and 1978, yielding a nearly complete (%75) skeleton only lacking most of the cranium, the pelvis and sternum. The bones were initially studied by Herculano Alvarenga, who first described them in 1982 as a species of ''Physornis''. Following closer examination of various phorusrhacid remains held in institutions across Europe, North ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligocene
The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the exact dates of the start and end of the epoch are slightly uncertain. The name Oligocene was coined in 1854 by the German paleontologist Heinrich Ernst Beyrich from his studies of marine beds in Belgium and Germany. The name comes from the Ancient Greek (''olígos'', "few") and (''kainós'', "new"), and refers to the sparsity of extant forms of molluscs. The Oligocene is preceded by the Eocene Epoch and is followed by the Miocene Epoch. The Oligocene is the third and final epoch of the Paleogene Period. The Oligocene is often considered an important time of transition, a link between the archaic world of the tropical Eocene and the more modern ecosystems of the Miocene. Major changes during the Oligocene included a global expansion o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Miocene
The Early Miocene (also known as Lower Miocene) is a sub-epoch of the Miocene Epoch made up of two stages: the Aquitanian and Burdigalian stages. The sub-epoch lasted from 23.03 ± 0.05 Ma to 15.97 ± 0.05 Ma (million years ago). It was preceded by the Oligocene epoch. As the climate started to get cooler, the landscape started to change. New mammals evolved to replace the extinct animals of the Oligocene epoch. The first members of the hyena and weasel family started to evolve to replace the extinct ''Hyaenodon'', entelodonts and bear-dogs. The chalicotheres survived the Oligocene epoch. A new genus of entelodont called ''Daeodon'' evolved in order to adapt to the new habitats and hunt the new prey animals of the Early Miocene epoch; it quickly became the top predator of North America. But it became extinct due to competition from '' Amphicyon'', a newcomer from Eurasia. ''Amphicyon'' bested ''Daeodon'' because the bear-dog Amphicyonidae is an extinct family of terrestr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Psilopterus
''Psilopterus'' (Greek for "bare wing") is an extinct genus of phorusrhacid ("terror bird") from the Middle Oligocene to possibly the Late Pleistocene of Argentina and Uruguay. Compared to other phorusrhacids, members of the genus are both relatively gracile and diminutive, and include the smallest known species of terror bird: with the head raised ''P. bachmanni'' was in height and weighed about , while the largest members of the genus were only about . The birds resemble the modern cariama (''Cariama cristata''), except with a heavier build and considerably smaller wings. The strong morphological similarity between the claws of the predatory cariama and ''Psilopterus'', both of which are sharp, curved, and laterally compressed, may indicate they were used to strike prey. In contrast to the other, larger terror birds, Tonni and Tambussi also suggested ''Psilopterus'' could use their claws to climb trees, and could even fly, but this has been rejected in more recent literature. F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesembriornis
''Mesembriornis'' is a genus of intermediate-sized phorusrhacids that grew up to in height. They represent a well-distinct lineage of terror birds, differing from the massive large groups and the smaller Psilopterinae. In general proportions, they most resembled the Patagornithinae which flourished somewhat earlier, mainly to the south of the range of ''Mesembriornis''. Fossils of the terror bird have been found in Montehermosan deposits of the Monte Hermoso Formation in Argentina.''Mesembriornis'' at .org Etymology The genus name, ''Mesembriornis'', means "southern bird" after its discovery in the[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Axis (anatomy)
In anatomy, the axis (from Latin ''axis'', "axle") or epistropheus is the second cervical vertebra (C2) of the spine, immediately inferior to the atlas, upon which the head rests. The axis' defining feature is its strong odontoid process (bony protrusion) known as the dens, which rises dorsally from the rest of the bone. Structure The body is deeper in front or in the back and is prolonged downward anteriorly to overlap the upper and front part of the third vertebra. It presents a median longitudinal ridge in front, separating two lateral depressions for the attachment of the longus colli muscles. Odontoid Process of Axis (Dens) The dens, also called the odontoid process or the peg, is the most pronounced projecting feature of the axis. The dens exhibits a slight constriction where it joins the main body of the vertebra. The condition where the dens is separated from the body of the axis is called ''os odontoideum'' and may cause nerve and circulation compression syndrome. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atlas (anatomy)
In anatomy, the atlas (C1) is the most superior (first) cervical vertebra of the spine and is located in the neck. It is named for Atlas of Greek mythology because, just as Atlas supported the globe, it supports the entire head. The atlas is the topmost vertebra and, with the axis (the vertebra below it), forms the joint connecting the skull and spine. The atlas and axis are specialized to allow a greater range of motion than normal vertebrae. They are responsible for the nodding and rotation movements of the head. The atlanto-occipital joint allows the head to nod up and down on the vertebral column. The dens acts as a pivot that allows the atlas and attached head to rotate on the axis, side to side. The atlas's chief peculiarity is that it has no body. It is ring-like and consists of an anterior and a posterior arch and two lateral masses. The atlas and axis are important neurologically because the brainstem extends down to the axis. Structure Anterior arch The anterio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lordosis
Lordosis is historically defined as an ''abnormal'' inward curvature of the lumbar spine. However, the terms ''lordosis'' and ''lordotic'' are also used to refer to the normal inward curvature of the lumbar and cervical regions of the human spine. Similarly, kyphosis historically refers to ''abnormal'' convex curvature of the spine. The normal outward (convex) curvature in the thoracic and sacral regions is also termed ''kyphosis'' or ''kyphotic''. The term comes from the Greek lordōsis, from ''lordos'' ("bent backward"). Lordosis in the human spine makes it easier for humans to bring the bulk of their mass over the pelvis. This allows for a much more efficient walking gait than that of other primates, whose inflexible spines cause them to resort to an inefficient forward leaning "bent-knee, bent-waist" gait. As such, lordosis in the human spine is considered one of the primary physiological adaptations of the human skeleton that allows for human gait to be as energeticall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kyphosis
Kyphosis is an abnormally excessive convex curvature of the spine as it occurs in the thoracic and sacral regions. Abnormal inward concave ''lordotic'' curving of the cervical and lumbar regions of the spine is called lordosis. It can result from degenerative disc disease; developmental abnormalities, most commonly Scheuermann's disease; Copenhagen disease, osteoporosis with compression fractures of the vertebra; multiple myeloma; or trauma. A normal thoracic spine extends from the 1st thoracic to the 12th thoracic vertebra and should have a slight kyphotic angle, ranging from 20° to 45°. When the "roundness" of the upper spine increases past 45° it is called kyphosis or "hyperkyphosis". Scheuermann's kyphosis is the most classic form of hyperkyphosis and is the result of wedged vertebrae that develop during adolescence. The cause is not currently known and the condition appears to be multifactorial and is seen more frequently in males than females. In the sense of a deformit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cervical Vertebrae
In tetrapods, cervical vertebrae (singular: vertebra) are the vertebrae of the neck, immediately below the skull. Truncal vertebrae (divided into thoracic and lumbar vertebrae in mammals) lie caudal (toward the tail) of cervical vertebrae. In sauropsid species, the cervical vertebrae bear cervical ribs. In lizards and saurischian dinosaurs, the cervical ribs are large; in birds, they are small and completely fused to the vertebrae. The vertebral transverse processes of mammals are homologous to the cervical ribs of other amniotes. Most mammals have seven cervical vertebrae, with the only three known exceptions being the manatee with six, the two-toed sloth with five or six, and the three-toed sloth with nine. In humans, cervical vertebrae are the smallest of the true vertebrae and can be readily distinguished from those of the thoracic or lumbar regions by the presence of a foramen (hole) in each transverse process, through which the vertebral artery, vertebral veins, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraphysornis Model Vienna
''Paraphysornis'' is an extinct genus of giant flightless terror birds that inhabited Brazil during Late Oligocene or Early Miocene epochs. Although not the tallest phorusrhacid, ''Paraphysornis'' was a notably robust bird, having short and robust tarsal bones not suited for pursuit hunting. Discovery and naming The holotype (DGM-1418-R) and only known fossil was discovered by a mining company in the Taubaté Basin (São Paulo State) in a layer of bentonite clay, two or three meters below a layer of Pyrobitumen. These sediments belong to the Late Oligocene to Early Miocene Tremembé Formation. Excavation of the bones took several months between 1977 and 1978, yielding a nearly complete (%75) skeleton only lacking most of the cranium, the pelvis and sternum. The bones were initially studied by Herculano Alvarenga, who first described them in 1982 as a species of ''Physornis''. Following closer examination of various phorusrhacid remains held in institutions across Europe, North ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physornis
''Physornis'' is an extinct genus of giant flightless predatory birds of the family Phorusrhacidae or "terror birds", most closely related to '' Paraphysornis'', that lived in Argentina. The type species is ''P. fortis''. It lived during the Middle to Late Oligocene ( Deseadan). Few fossils are known, but the available material suggests that ''Physornis'' was one of the largest phorusrhacids. History and taxonomy The holotype of ''Physornis'' ( BMNH-A583) is a 137 mm long portion of a symphysis and the right branch of this lower jaw, described in 1894 by paleontologist Florentino Ameghino. He published the name, together with a description but without a drawing, in the same year.Brodkorb, P. (1967). ''Catalogue of fossil birds: part 3 (Ralliformes, Ichthyornithiformes, Charadriiformes)''. University of Florida.Alvarenga, H. M., & Höfling, E. (2003). Systematic revision of the Phorusrhacidae (Aves: Ralliformes). ''Papéis Avulsos de Zoologia'', ''43''(4), 55-91. The fossil was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sternum
The sternum or breastbone is a long flat bone located in the central part of the chest. It connects to the ribs via cartilage and forms the front of the rib cage, thus helping to protect the heart, lungs, and major blood vessels from injury. Shaped roughly like a necktie, it is one of the largest and longest flat bones of the body. Its three regions are the manubrium, the body, and the xiphoid process. The word "sternum" originates from the Ancient Greek στέρνον (stérnon), meaning "chest". Structure The sternum is a narrow, flat bone, forming the middle portion of the front of the chest. The top of the sternum supports the clavicles (collarbones) and its edges join with the costal cartilages of the first two pairs of ribs. The inner surface of the sternum is also the attachment of the sternopericardial ligaments. Its top is also connected to the sternocleidomastoid muscle. The sternum consists of three main parts, listed from the top: * Manubrium * Body (gladiolus) * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
