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Megacephalosaurus Eulerti
''Megacephalosaurus'' (; "great-headed lizard") is an extinct genus of short-necked pliosaur that inhabited the Western Interior Seaway of North America about 94 to 93 million years ago during the Turonian stage of the Late Cretaceous, containing the single species ''M. eulerti''. It is named after its large head, which is the largest of any plesiosaur in the continent and measures up to in length. ''Megacephalosaurus'' was one of the largest marine reptiles of its time with an estimated length of . Its long snout and consistently sized teeth suggest that it preferred a diet on smaller-sized prey. Remains representing the pliosaur include two fossil skulls, three ribs, and a neural arch. The fossils have been found in deposits of the Carlile Shale and Greenhorn Limestone in Kansas and elsewhere in the midwestern United States. First discovered in 1950, they were originally thought to have been giant fossils of a closely related pliosaur known as '' Brachauchenius lucasi''. But b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turonian
The Turonian is, in the ICS' geologic timescale, the second age in the Late Cretaceous Epoch, or a stage in the Upper Cretaceous Series. It spans the time between 93.9 ± 0.8 Ma and 89.8 ± 1 Ma (million years ago). The Turonian is preceded by the Cenomanian Stage and underlies the Coniacian Stage. At the beginning of the Turonian an oceanic anoxic event (OAE 2) took place, also referred to as the Cenomanian-Turonian boundary event or the "Bonarelli Event". Stratigraphic definition The Turonian (French: ''Turonien'') was defined by the French paleontologist Alcide d'Orbigny (1802–1857) in 1842. Orbigny named it after the French city of Tours in the region of Touraine (department Indre-et-Loire), which is the original type locality. The base of the Turonian Stage is defined as the place where the ammonite species '' Watinoceras devonense'' first appears in the stratigraphic column. The official reference profile (the GSSP) for the base of the Turonian is located in the Roc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cervical Rib
A cervical rib in humans is an extra rib which arises from the seventh cervical vertebra. Their presence is a congenital abnormality located above the normal first rib. A cervical rib is estimated to occur in 0.2% to 0.5% (1 in 200 to 500) of the population. People may have a cervical rib on the right, left or both sides. Most cases of cervical ribs are not clinically relevant and do not have symptoms; cervical ribs are generally discovered incidentally, most often during x-rays and CT scans. However, they vary widely in size and shape, and in rare cases, they may cause problems such as contributing to thoracic outlet syndrome, because of pressure on the nerves that may be caused by the presence of the rib. A cervical rib represents a persistent ossification of the C7 lateral costal element. During early development, this ossified costal element typically becomes re-absorbed. Failure of this process results in a variably elongated transverse process or complete rib that can be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megacephalosaurus Skull
''Megacephalosaurus'' (; "great-headed lizard") is an extinct genus of short-necked pliosaur that inhabited the Western Interior Seaway of North America about 94 to 93 million years ago during the Turonian stage of the Late Cretaceous, containing the single species ''M. eulerti''. It is named after its large head, which is the largest of any plesiosaur in the continent and measures up to in length. ''Megacephalosaurus'' was one of the largest marine reptiles of its time with an estimated length of . Its long snout and consistently sized teeth suggest that it preferred a diet on smaller-sized prey. Remains representing the pliosaur include two fossil skulls, three ribs, and a neural arch. The fossils have been found in deposits of the Carlile Shale and Greenhorn Limestone in Kansas and elsewhere in the midwestern United States. First discovered in 1950, they were originally thought to have been giant fossils of a closely related pliosaur known as '' Brachauchenius lucasi''. Bu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jurassic
The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The Jurassic constitutes the middle period of the Mesozoic, Mesozoic Era and is named after the Jura Mountains, where limestone strata from the period were first identified. The start of the Jurassic was marked by the major Triassic–Jurassic extinction event, associated with the eruption of the Central Atlantic magmatic province, Central Atlantic Magmatic Province. The beginning of the Toarcian Stage started around 183 million years ago and is marked by an extinction event associated with widespread Anoxic event, oceanic anoxia, ocean acidification, and elevated temperatures likely caused by the eruption of the Karoo-Ferrar, Karoo-Ferrar large igneous provinces. The end of the Jurassic, however, has no clear boundary with the Cretaceous and i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sachicasaurus
''Sachicasaurus'' is an extinct genus of brachauchenine pliosaurid known from the Barremian of the Paja Formation, Altiplano Cundiboyacense in the Colombian Eastern Ranges of the Andes. The type species is ''S. vitae''. Etymology The genus name ''Sachicasaurus'' refers to Sáchica, the village where the fossil was found, and ''saurus'', meaning "lizard" in Greek.Páramo Fonseca ''et al.'', 2018, p.225 The species epithet ''vitae'', meaning "life" in Latin, was chosen because of the life in Sáchica the fossil find has sparked.Páramo Fonseca ''et al.'', 2018, p.226 Description The holotype specimen, MP111209-1, is known from a near complete skull, and postcranial elements including a complete hindlimb and various vertebrae. Diagnostic features include a very short mandibular symphysis, reduced number of mandibular teeth (17 to 18 versus 25 to 40 in other pliosaurids),Páramo Fonseca ''et al.'', 2018, p.232 slender teeth, among other features. The specimen has an estimated le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acostasaurus
''Acostasaurus'' (meaning "Acosta's lizard") is an extinct genus of possibly Thalassophonean pliosaurid known from the Barremian of the Paja Formation, Colombia. The type specimen, UNDG R-1000, is known from a near complete skull, and postcranial elements including a complete hindlimb and various vertebrae.Marcela Gómez Pérez; Leslie F. Noè (2017). "Cranial anatomy of a new pliosaurid ''Acostasaurus pavachoquensis'' from the Lower Cretaceous of Colombia, South America". Palaeontographica Abteilung A. 310 (1–2): 5–42. . The specimen has an estimated size of over in length and in body mass. Description The type specimen is noted for possessing several features that pertain to a sub adult individual: for example, the sagittal crest is not fully ossified, as well as possessing undeveloped palatine wings. It is possible however that ''Acostasaurus'', like other plesiosaurs, was paedomorphic. From what is preserved, the orbits are large, rounded and deeply notched dorsally. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kronosaurus
''Kronosaurus'' ( ; meaning "lizard of Kronos") is a potentially dubious genus of extinct short-necked pliosaur. With an estimated length of , it was among the largest pliosaurs, and is named after the leader of the Greek Titans, Kronos. It lived in the Early Cretaceous period (Aptian to Late Albian).Hampe O. 1992. Ein großwüchsiger Pliosauride (Reptilia: Plesiosauria) aus der Unterkreide (oberes Aptium) von Kolumbien. ''Courier Forschungsinstitut Senckenberg'' 145: 1–32.Kear BP. 2003Cretaceous marine reptiles of Australia: a review of taxonomy and distribution ''Cretaceous Research'' 24: 277–303. Fossil material has been recovered from the Toolebuc Formation (middle to late Albian) and Wallumbilla Formations (Aptian) of Queensland and New South Wales in Australia. Discovery In 1899, Andrew Crombie of Hughenden discovered a "scrap of bone" containing six conical teeth, and gave this fragmentary fossil to the Queensland Museum. Twenty-five years later, then-director He ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dental Alveolus
Dental alveoli (singular ''alveolus'') are sockets in the jaws in which the roots of teeth are held in the alveolar process with the periodontal ligament. The lay term for dental alveoli is tooth sockets. A joint that connects the roots of the teeth and the alveolus is called ''gomphosis'' (plural ''gomphoses''). Alveolar bone is the bone that surrounds the roots of the teeth forming bone sockets. In mammals, tooth sockets are found in the maxilla, the premaxilla, and the mandible. Etymology 1706, "a hollow," especially "the socket of a tooth," from Latin alveolus "a tray, trough, basin; bed of a small river; small hollow or cavity," diminutive of alvus "belly, stomach, paunch, bowels; hold of a ship," from PIE root *aulo- "hole, cavity" (source also of Greek aulos "flute, tube, pipe;" Serbo-Croatian, Polish, Russian ulica "street," originally "narrow opening;" Old Church Slavonic uliji, Lithuanian aulys "beehive" (hollow trunk), Armenian yli "pregnant"). The word was extended in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pliosaurus
''Pliosaurus'' (meaning 'more lizard') is an extinct genus of thalassophonean pliosaurid known from the Kimmeridgian and Tithonian stages (Late Jurassic) of Europe and South America. Their diet would have included fish, cephalopods, and marine reptiles. This genus has contained many species in the past but recent reviews found only six (''P. brachydeirus'', ''P. carpenteri'', ''P. funkei'', ''P. kevani'', ''P. rossicus'' and ''P. westburyensis'') to be valid, while the validity of two additional species awaits a petition to the International Code of Zoological Nomenclature. Currently, ''P. brachyspondylus'' and ''P. macromerus'' are considered dubious, while ''P. portentificus'' is considered undiagnostic. Most species of ''Pliosaurus'' reached in length and in body mass, while ''P. rossicus'' and ''P. funkei'' may have reached or even exceeded in length and in body mass, being the largest plesiosaurs of all time. Species of this genus are differentiated from other pliosaurids ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liopleurodon
''Liopleurodon'' (; meaning 'smooth-sided teeth') is an extinct genus of large, carnivorous marine reptile belonging to the Thalassophonea, a clade of short-necked pliosaurid plesiosaurs. ''Liopleurodon'' lived from the Callovian Stage of the Middle Jurassic to the Kimmeridgian stage of the Late Jurassic Period (c. 166 to 155 mya). It was the apex predator of the Middle to Late Jurassic seas that covered Europe. The largest species, ''L. ferox'', is estimated to have grown up to in length, but could have been larger. The name "Liopleurodon" (meaning "smooth-sided tooth") derives from Ancient Greek words: ', "smooth"; ', "side" or "rib"; and ', "tooth". Discovery and species Even before ''Liopleurodon'' was named, material likely belonging to it was described. In 1841, Hermann von Meyer named the species ''Thaumatosaurus oolithicus'' based on a fragmentary specimen consisting of partial teeth, skull elements, vertebrae, and ribs from deposits in Württemberg, Germany possi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maxilla
The maxilla (plural: ''maxillae'' ) in vertebrates is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The two maxillary bones are fused at the intermaxillary suture, forming the anterior nasal spine. This is similar to the mandible (lower jaw), which is also a fusion of two mandibular bones at the mandibular symphysis. The mandible is the movable part of the jaw. Structure In humans, the maxilla consists of: * The body of the maxilla * Four processes ** the zygomatic process ** the frontal process of maxilla ** the alveolar process ** the palatine process * three surfaces – anterior, posterior, medial * the Infraorbital foramen * the maxillary sinus * the incisive foramen Articulations Each maxilla articulates with nine bones: * two of the cranium: the frontal and ethmoid * seven of the face: the nasal, zygomatic, lacrimal, inferior n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Premaxilla
The premaxilla (or praemaxilla) is one of a pair of small cranial bones at the very tip of the upper jaw of many animals, usually, but not always, bearing teeth. In humans, they are fused with the maxilla. The "premaxilla" of therian mammal has been usually termed as the incisive bone. Other terms used for this structure include premaxillary bone or ''os premaxillare'', intermaxillary bone or ''os intermaxillare'', and Goethe's bone. Human anatomy In human anatomy, the premaxilla is referred to as the incisive bone (') and is the part of the maxilla which bears the incisor teeth, and encompasses the anterior nasal spine and alar region. In the nasal cavity, the premaxillary element projects higher than the maxillary element behind. The palatal portion of the premaxilla is a bony plate with a generally transverse orientation. The incisive foramen is bound anteriorly and laterally by the premaxilla and posteriorly by the palatine process of the maxilla. It is formed from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
