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Glyphoderma
''Glyphoderma'' is an extinct genus of placodont reptile from the Middle Triassic of China. It differs from its relative ''Psephochelys'' in having three, rather than one, fused osteoderms on the posterior skull surface, and has an earlier temporal range, from the Ladinian epoch rather than the Late Triassic. Otherwise, it is similar in most respects to the other plachochelyids found in China. The name comes from the Greek 'γλυφος', 'sculpture' and 'δερμα', 'skin' referring to its unique carapace structure. The specific name honours a Mr. Kang Ximin. The holotype, an almost complete skeleton, was found in 2008 in Fuyuan, Yunnan Province of central China in the Zhuganpo Formation. It is preserved in a thick block of limestone, and so the ventral side is not well known. The total length is 873 mm. Features Skull ''Glyphodermas skull is the shape of an isosceles triangle, with a long narrow rostrum. The skull is 110.6 mm long and 83.7 mm wide. There are three l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2008 In Paleontology
Protozoa New taxa Plants Angiosperms Monocots Arthropoda Arachnids Insects Xiphosurans Fishes Bony fish Placoderms General research *Hilton & Grande redescribe the fossil mooneyes of western North America synonymizing the genus ''Eohiodon'' with ''Hiodon''. *Cicimurri, Paris, & Everhart describe a partial dentition from a Holocephali chimaeroid fish found in the Niobrara Chalk. Amphibians Jenkins, F. A., jr, Shubin, N. H., Gatesy, S. M., and Warren, A., 2008, Gerrothorax pulcherrimus from the Upper Triassic Fleming Fjord Formation of East Greenland and a reassessment of head lifting in temnospondyl feeding: Journal of Vertebrate Paleontology, v. 28, n. 4, p. 935-950. Newly named amphibians Archosaurs Newly named pseudosuchians Newly named pterosaurs Dinosaurs * Oviraptorosaurian eggs with embryonic skeletons are discovered for the first time in China. * Mongolian Late Jurassic theropod fossils are found for the first time. * A new study on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Placochelyidae
Placochelyidae is an extinct family of placodonts belonging to the superfamily Cyamodontoidea. Genus *''Glyphoderma'' *''Placochelys'' *''Psephosauriscus'' *''Psephochelys ''Psephochelys (meaning "pebbly turtle")'' is an extinct genus of placodont reptile from the Late Triassic of China. It is represented by a single species, ''Psephochelys polyosteoderma'', named in 2002 on the basis of a single partial skeleton ...'' *'' Psephoderma'' References Placodonts Prehistoric reptile families Triassic sauropterygians Middle Triassic first appearances Late Triassic first appearances {{triassic-reptile-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Placodont
Placodonts (" Tablet teeth") are an extinct order of marine reptiles that lived during the Triassic period, becoming extinct at the end of the period. They were part of Sauropterygia, the group that includes plesiosaurs. Placodonts were generally between in length, with some of the largest measuring long. The first specimen was discovered in 1830. They have been found throughout central Europe, North Africa, the Middle East and China. Palaeobiology The earliest forms, like ''Placodus'', which lived in the early to middle Triassic, resembled barrel-bodied lizards superficially similar to the marine iguana of today, but larger. In contrast to the marine iguana, which feeds on algae, the placodonts ate molluscs and so their teeth were flat and tough to crush shells. In the earliest periods, their size was probably enough to keep away the top sea predators of the time: the sharks. However, as time passed, other kinds of carnivorous reptiles began to colonize the seas, such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zhuganpo Formation
The Zhuganpo Formation is a Triassic geologic unit found in southern China. It has historically been known as the Zhuganpo Member of the Falang Formation. A diverse fossil assemblage known as the Xingyi biota or Xingyi Fauna can be found in the upper part of the Zhuganpo Formation. Fossils of the Xingyi biota include articulated skeletons of marine reptiles, abundant fish, and a plentiful assortment of invertebrates indicating a Ladinian to Carnian age for the sediments of the formation. Paleobiota Invertebrates * Ammonites: '' Clionitites'' sp., '' Detoniceras'' sp., '' Haoceras xingyiense'', '' Parasturia'' sp., ''Protrachyceras'' sp., ''Ptychites'' sp., '' Sinomeginoceras'' (''S. wangi, S. xingyiense''), ''Trachyceras'' sp., '' Xenoprotrachyceras'' cf. ''primum'', '' Yangites densicostatus'', * Bivalves: ''Daonella'' sp. * Conodonts: '' Gladigondolella malayensis'', ''Metapolygnathus'' / '' Paragondolella'' / '' Quadralella'' (''Q.'' aff''. acuminatus, P. foliata, P. incli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbit (anatomy)
In anatomy, the orbit is the cavity or socket of the skull in which the eye and its appendages are situated. "Orbit" can refer to the bony socket, or it can also be used to imply the contents. In the adult human, the volume of the orbit is , of which the eye occupies . The orbital contents comprise the eye, the orbital and retrobulbar fascia, extraocular muscles, cranial nerves II, III, IV, V, and VI, blood vessels, fat, the lacrimal gland with its sac and duct, the eyelids, medial and lateral palpebral ligaments, cheek ligaments, the suspensory ligament, septum, ciliary ganglion and short ciliary nerves. Structure The orbits are conical or four-sided pyramidal cavities, which open into the midline of the face and point back into the head. Each consists of a base, an apex and four walls."eye, human."Encyclopædia Britannica from Encyclopædia Britannica 2006 Ultimate Reference Suite DVD 2009 Openings There are two important foramina, or windows, two important fissu ... [...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] |
Placochelys
''Placochelys'' ('flat-plate turtle") is an extinct genus of placodont reptiles erected by Otto Jaekel in 1902. Fossil records Fossils of ''Placochelys'' dates back to the Triassic period (age range: 221.5 to 205.6 million years ago). They have been found in Germany, Austria, Hungary and Italy. Species This genus includes only one species: * ''Placochelys placodonta'' Jaekel, 1902 (from Upper Ladinian of Hungary) Description ''Placochelys'' looked remarkably similar to a sea turtle, and grew to about in length. It had a flat turtle-like carapace covered with knobbly plates, and a compact triangular skull. Its beaked skull had powerful muscles. It had only two pairs of palatal teeth, a large posterior pair, and a small rostral pair. The specialized broad teeth on the palate, were most likely used for crushing shellfish Shellfish is a colloquial and fisheries term for exoskeleton-bearing aquatic invertebrates used as food, including various species of molluscs, crustace ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nostril
A nostril (or naris , plural ''nares'' ) is either of the two orifices of the nose. They enable the entry and exit of air and other gasses through the nasal cavities. In birds and mammals, they contain branched bones or cartilages called turbinates, whose function is to warm air on inhalation and remove moisture on exhalation. Fish do not breathe through noses, but they do have two (but cyclostomes have merged into one) small holes used for smelling, which can also be referred to as nostrils. In humans, the nasal cycle is the normal ultradian cycle of each nostril's blood vessels becoming engorged in swelling, then shrinking. The nostrils are separated by the septum. The septum can sometimes be deviated, causing one nostril to appear larger than the other. With extreme damage to the septum and columella, the two nostrils are no longer separated and form a single larger external opening. Like other tetrapods, humans have two external nostrils (anterior nares) and two additi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middle Triassic
In the geologic timescale, the Middle Triassic is the second of three epochs of the Triassic period or the middle of three series in which the Triassic system is divided in chronostratigraphy. The Middle Triassic spans the time between Ma and Ma (million years ago). It is preceded by the Early Triassic Epoch and followed by the Late Triassic Epoch. The Middle Triassic is divided into the Anisian and Ladinian ages or stages. Formerly the middle series in the Triassic was also known as Muschelkalk. This name is now only used for a specific unit of rock strata with approximately Middle Triassic age, found in western Europe. Middle Triassic fauna Following the Permian–Triassic extinction event, the most devastating of all mass-extinctions, life recovered slowly. In the Middle Triassic, many groups of organisms reached higher diversity again, such as the marine reptiles (e.g. ichthyosaurs, sauropterygians, thallatosaurs), ray-finned fish and many invertebrate groups like ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temporal Fenestrae
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] |
Jugal Bone
The jugal is a skull bone found in most reptiles, amphibians and birds. In mammals, the jugal is often called the malar or zygomatic. It is connected to the quadratojugal and maxilla, as well as other bones, which may vary by species. Anatomy The jugal bone is located on either side of the skull in the circumorbital region. It is the origin of several masticatory muscles in the skull. The jugal and lacrimal bones are the only two remaining from the ancestral circumorbital series: the prefrontal, postfrontal, postorbital, jugal, and lacrimal bones. During development, the jugal bone originates from dermal bone. In dinosaurs This bone is considered key in the determination of general traits in cases in which the entire skull has not been found intact (for instance, as with dinosaurs in paleontology). In some dinosaur genera the jugal also forms part of the lower margin of either the antorbital fenestra or the infratemporal fenestra, or both. Most commonly, this bone articu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mandible
In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower tooth, teeth in place. The mandible sits beneath the maxilla. It is the only movable bone of the skull (discounting the ossicles of the middle ear). It is connected to the temporal bones by the temporomandibular joints. The bone is formed prenatal development, in the fetus from a fusion of the left and right mandibular prominences, and the point where these sides join, the mandibular symphysis, is still visible as a faint ridge in the midline. Like other symphyses in the body, this is a midline articulation where the bones are joined by fibrocartilage, but this articulation fuses together in early childhood.Illustrated Anatomy of the Head and Neck, Fehrenbach and Herring, Elsevier, 2012, p. 59 The word "mandible" derives from the Latin word ''mandibula'', "jawbone" (literally "one used for chewing"), from ''wikt:mandere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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