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Phantomosaurus
''Phantomosaurus'' is an extinct genus of ichthyosaur that lived during the late Anisian stage of the Middle Triassic. Fossils have been found in southern Germany. It was discovered in 1965 and named in 1997 as a species of '' Shastasaurus'' by Sander in the rocks of the Upper Muschelkalk. More recently, in 2005, the braincase was studied by Maisch and Matzke. They found it to be unique among all known ichthyosaurs in terms of braincase morphology. Despite its close relation to many other ichthyosaurs, in particular ''Cymbospondylus, Phantomosaurus'' appears to have a very primitive braincase which resembles other diapsids more than other ichthyosaurs. Morphology ''Phantomosaurus'' is known from a partial skull, the lower jaw, some of the vertebrae and ribs (pictured) and the hind fin. Hind fin The hind fin is very long and slender, with elongated femur, tibia and fibula. These features suggest a long but not particularly powerful limb, which would have generated a reaso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shastasaurus
''Shastasaurus'' ("Mount Shasta lizard") is a very large extinct genus of ichthyosaur from the middle and late Triassic, and is the largest known marine reptile.Hilton, Richard P., ''Dinosaurs and Other Mesozoic Animals of California'', University of California Press, Berkeley 2003 , at pages 90-91. Specimens have been found in the United States, Canada, and China. Description left, Size of '' Shonisaurus popularis'' (green) and ''S. sikanniensis'' (red), a possible species of ''Shastasaurus'', compared with a human ''Shastasaurus'' lived during the late Triassic period. The type species ''Shastasaurus pacificus'' is known from California. ''S. pacificus'' was a medium-sized ichthyosaur, measuring over in length and weighing . A second possible species of ''Shastasaurus'', ''S. sikanniensis'', is known from the Pardonet Formation British Columbia, dating to the middle Norian age (about 210 million years ago). If ''S.sikanniensis'' belongs to ''Shastasaurus'', it would be the la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cymbospondylus
''Cymbospondylus'' (a Greek word meaning "boat vertebrae") was a basal early ichthyosaur that lived between the early and middle Triassic period (249-237 million years ago). Previously, the genus was classified as a shastasaurid, but more recent work finds it to be more basal.Motani, R. 1999: Phylogeny of the Ichthyopterygia. Journal of Vertebrate Paleontology. 19 (3): 473 – 496 ''Cymbospondylus'' was a cosmopolitan genus found in Nevada, Europe ( Switzerland, Germanic Basin) and Spitsbergen. History ''Cymbospondylus'' was described from Nevada by Joseph Leidy in 1868 on the basis of several fragmentary vertebrae which he assigned to two different species: ''C. piscosus'' (the type species) and ''C. petrinus''. The University of California, under the direction of John Campbell Merriam and funded by Annie Alexander, conducted extensive fieldwork in the region in the late nineteenth and early twentieth century, following the description of ''Cymbospondylus'', recovering add ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ichthyosaur
Ichthyosaurs (Ancient Greek for "fish lizard" – and ) are large extinct marine reptiles. Ichthyosaurs belong to the order known as Ichthyosauria or Ichthyopterygia ('fish flippers' – a designation introduced by Sir Richard Owen in 1842, although the term is now used more for the parent clade of the Ichthyosauria). Ichthyosaurs thrived during much of the Mesozoic era; based on fossil evidence, they first appeared around 250 million years ago ( Ma) and at least one species survived until about 90 million years ago, into the Late Cretaceous. During the Early Triassic epoch, ichthyosaurs and other ichthyosauromorphs evolved from a group of unidentified land reptiles that returned to the sea, in a development similar to how the mammalian land-dwelling ancestors of modern-day dolphins and whales returned to the sea millions of years later, which they gradually came to resemble in a case of convergent evolution. Ichthyosaurs were particularly abundant in the Late Triassic a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ichthyosaur
Ichthyosaurs (Ancient Greek for "fish lizard" – and ) are large extinct marine reptiles. Ichthyosaurs belong to the order known as Ichthyosauria or Ichthyopterygia ('fish flippers' – a designation introduced by Sir Richard Owen in 1842, although the term is now used more for the parent clade of the Ichthyosauria). Ichthyosaurs thrived during much of the Mesozoic era; based on fossil evidence, they first appeared around 250 million years ago ( Ma) and at least one species survived until about 90 million years ago, into the Late Cretaceous. During the Early Triassic epoch, ichthyosaurs and other ichthyosauromorphs evolved from a group of unidentified land reptiles that returned to the sea, in a development similar to how the mammalian land-dwelling ancestors of modern-day dolphins and whales returned to the sea millions of years later, which they gradually came to resemble in a case of convergent evolution. Ichthyosaurs were particularly abundant in the Late Triassic a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skull
The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, these two parts are the neurocranium and the viscerocranium ( facial skeleton) that includes the mandible as its largest bone. The skull forms the anterior-most portion of the skeleton and is a product of cephalisation—housing the brain, and several sensory structures such as the eyes, ears, nose, and mouth. In humans these sensory structures are part of the facial skeleton. Functions of the skull include protection of the brain, fixing the distance between the eyes to allow stereoscopic vision, and fixing the position of the ears to enable sound localisation of the direction and distance of sounds. In some animals, such as horned ungulates (mammals with hooves), the skull also has a defensive function by providing the mount (on the front ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quadratojugal Bone
The quadratojugal is a skull bone present in many vertebrates, including some living reptiles and amphibians. Anatomy and function In animals with a quadratojugal bone, it is typically found connected to the jugal (cheek) bone from the front and the squamosal bone from above. It is usually positioned at the rear lower corner of the cranium. Many modern tetrapods lack a quadratojugal bone as it has been lost or fused to other bones. Modern examples of tetrapods without a quadratojugal include salamanders, mammals, birds, and squamates (lizards and snakes). In tetrapods with a quadratojugal bone, it often forms a portion of the jaw joint. Developmentally, the quadratojugal bone is a dermal bone in the temporal series, forming the original braincase. The squamosal and quadratojugal bones together form the cheek region and may provide muscular attachments for facial muscles. In reptiles and amphibians In most modern reptiles and amphibians, the quadratojugal is a prominent, strapl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Disarticulation
In medical terminology, disarticulation is the separation of two bones at their joint, either traumatically by way of injury or by a surgeon during arthroplasty or amputation. See also * Joint dislocation * Acrotomophilia * Apotemnophilia * Amputation Amputation is the removal of a limb by trauma, medical illness, or surgery. As a surgical measure, it is used to control pain or a disease process in the affected limb, such as malignancy or gangrene. In some cases, it is carried out on indi ... References Musculoskeletal disorders Amputations {{musculoskeletal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Suprangular
The suprangular or surangular is a jaw bone found in most land vertebrates, except mammals. Usually in the back of the jaw, on the upper edge, it is connected to all other jaw bones: dentary, angular, splenial and articular The articular bone is part of the lower jaw of most vertebrates, including most jawed fish, amphibians, birds and various kinds of reptiles, as well as ancestral mammals. Anatomy In most vertebrates, the articular bone is connected to two oth .... It is often a muscle attachment site. References Vertebrate anatomy {{Vertebrate anatomy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Articular Bone
The articular bone is part of the lower jaw of most vertebrates, including most jawed fish, amphibians, birds and various kinds of reptiles, as well as ancestral mammals. Anatomy In most vertebrates, the articular bone is connected to two other lower jaw bones, the suprangular and the angular. Developmentally, it originates from the embryonic mandibular cartilage. The most caudal portion of the mandibular cartilage ossifies to form the articular bone, while the remainder of the mandibular cartilage either remains cartilaginous or disappears. In snakes In snakes, the articular, surangular, and prearticular bones have fused to form the compound bone. The mandible is suspended from the quadrate bone and articulates at this compound bone. Function In amphibians and reptiles In most tetrapods, the articular bone forms the lower portion of the jaw joint. The upper jaw articulates at the quadrate bone. In mammals In mammals, the articular bone evolves to form the malleu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vertebra
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] |
Fish
Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of living fish species are ray-finned fish, belonging to the class Actinopterygii, with around 99% of those being teleosts. The earliest organisms that can be classified as fish were soft-bodied chordates that first appeared during the Cambrian period. Although they lacked a true spine, they possessed notochords which allowed them to be more agile than their invertebrate counterparts. Fish would continue to evolve through the Paleozoic era, diversifying into a wide variety of forms. Many fish of the Paleozoic developed external armor that protected them from predators. The first fish with jaws appeared in the Silurian period, after which many (such as sharks) became formidable marine predators rather than just the prey of arthropods. Mos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tooth
A tooth ( : teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tearing food, for defensive purposes, to intimidate other animals often including their own, or to carry prey or their young. The roots of teeth are covered by gums. Teeth are not made of bone, but rather of multiple tissues of varying density and hardness that originate from the embryonic germ layer, the ectoderm. The general structure of teeth is similar across the vertebrates, although there is considerable variation in their form and position. The teeth of mammals have deep roots, and this pattern is also found in some fish, and in crocodilians. In most teleost fish, however, the teeth are attached to the outer surface of the bone, while in lizards they are attached to the inner surface of the jaw by one side. In cartilaginous fish, s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
