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Thaisaurus
''Thaisaurus'' is an extinct genus of ichthyopterygian marine reptile that lived during the Spathian (late Olenekian, Early Triassic). Fossils have been found in Thailand.New Material of ''Qianichtyosaurus'' Li, 1999 (Reptilia, Ichthyosauria) from the late Triassic of southern China, and Implications for the Distribution of Triassic Ichthyosaurs. Elizabeth L. Nicholls, Chen Wei, Makoto Manabe. Discovery The type specimen of ''Thaisaurus'' was discovered by Chongpan Chonglakmani on the hill Khao Thong, around Phattalung, Thailand. This specimen consists of a skull, partial vertebral series, and an incomplete fore- and hindlimb and was preserved in resistant Dolomite (rock), dolomite, alongside two other poorly preserved Fossil#Casts and molds, natural molds of other specimens. The type specimen was subsequently extracted in 1988 by a joint paleontological expedention from Thailand and France. The specimen is housed in the Department of Mineral Resources (Thailand), Department of M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ichthyopterygia
Ichthyopterygia ("fish flippers") was a designation introduced by Richard Owen, Sir Richard Owen in 1840 to designate the Jurassic ichthyosaurs that were known at the time, but the term is now used more often for both true Ichthyosauria and their more primitive early and middle Triassic ancestors. Basal (phylogenetics), Basal ichthyopterygians (prior to and ancestral to true Ichthyosauria) were mostly small (a meter or less in length) with elongated bodies and long, spool-shaped vertebrae, indicating that they swam in a sinuous, eel-like manner. This allowed for quick movements and maneuverability that were advantages in shallow-water hunting. Even at this early stage, they were already very specialised animals with proper flippers, and would have been incapable of movement on land. These animals seem to have been widely distributed around the coast of the northern half of Pangea, as they are known from the Olenekian (Early Triassic) and early Anisian (early Middle Triassic) of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Triassic
The Early Triassic is the first of three epochs of the Triassic Period of the geologic timescale. It spans the time between 251.9 Ma and Ma (million years ago). Rocks from this epoch are collectively known as the Lower Triassic Series, which is a unit in chronostratigraphy. The Early Triassic is the oldest epoch of the Mesozoic Era. It is preceded by the Lopingian Epoch (late Permian, Paleozoic Era) and followed by the Middle Triassic Epoch. The Early Triassic is divided into the Induan and Olenekian ages. The Induan is subdivided into the Griesbachian and Dienerian subages and the Olenekian is subdivided into the Smithian and Spathian subages. The Lower Triassic series is coeval with the Scythian Stage, which is today not included in the official timescales but can be found in older literature. In Europe, most of the Lower Triassic is composed of Buntsandstein, a lithostratigraphic unit of continental red beds. The Early Triassic and partly also the Middle Trias ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lizard
Lizard is the common name used for all Squamata, squamate reptiles other than snakes (and to a lesser extent amphisbaenians), encompassing over 7,000 species, ranging across all continents except Antarctica, as well as most Island#Oceanic islands, oceanic Archipelago, island chains. The grouping is Paraphyly, paraphyletic as some lizards are more closely related to snakes than they are to other lizards. Lizards range in size from chameleons and geckos a few centimeters long to the 3-meter-long Komodo dragon. Most lizards are quadrupedal, running with a strong side-to-side motion. Some lineages (known as "legless lizards") have secondarily lost their legs, and have long snake-like bodies. Some lizards, such as the forest-dwelling ''Draco (genus), Draco'', are able to glide. They are often Territory (animal), territorial, the males fighting off other males and signalling, often with bright colours, to attract mates and to intimidate rivals. Lizards are mainly carnivorous, often b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caudal Vertebrae
Caudal vertebrae are the vertebrae of the tail in many vertebrates. In birds, the last few caudal vertebrae fuse into the pygostyle, and in apes, including humans, the caudal vertebrae are fused into the coccyx. In many reptiles, some of the caudal vertebrae bear ribs, the caudal ribs, though these are often fused with the vertebrae. The caudal vertebrae often articulate with haemal arches ventrally. The number of caudal vertebrae in animals can vary greatly. Anguid lizards have been reported to have as many as 111 caudal vertebrae, whereas as few as seven are present in the tail of the early therapsid ''Tapinocaninus''. In lepidosaurs and captorhinids, the caudal vertebrae possess fracture planes at mid-length that allow caudal autotomy. In frogs, the few caudal vertebrae are fused together to form part of the urostyle. References Skeletal system Vertebrate anatomy {{vertebrate-anatomy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vertebral Centra
Each vertebra (: vertebrae) is an irregular bone with a complex structure composed of bone and some hyaline cartilage, that make up the vertebral column or spine, of vertebrates. The proportions of the vertebrae differ according to their spinal segment and the particular species. The basic configuration of a vertebra varies; the vertebral body (also ''centrum'') is of bone and bears the load of the vertebral column. The upper and lower surfaces of the vertebra body give attachment to the intervertebral discs. The posterior part of a vertebra forms a vertebral arch, in eleven parts, consisting of two pedicles (pedicle of vertebral arch), two laminae, and seven processes. The laminae give attachment to the ligamenta flava (ligaments of the spine). There are vertebral notches formed from the shape of the pedicles, which form the intervertebral foramina when the vertebrae articulate. These foramina are the entry and exit conduits for the spinal nerves. The body of the vertebra and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grippia
''Grippia'' is a genus of early ichthyopterygian, an extinct group of reptiles that resembled dolphins. Its only species is ''Grippia longirostris''. It was a relatively small ichthyopterygian, measuring around long. Fossil remains from Svalbard from the specimen SVT 203 were originally assigned to ''G. longirostris'' but are now thought to have belonged to a non-ichthyopterygian diapsid related to '' Helveticosaurus''. Discovery Fossils have been found along the coasts of Greenland, China, Japan, Norway, and Canada ( Sulfur Mountain Formation); of Early Triassic age. No complete skeletons have ever been found. However, well-preserved remains have been found, with the most notable ones including: *The Marine Ironstone found in Agardh Bay Norway. This specimen consists of a partial skull fossil; however, it was lost during World War II and presumably destroyed. *Previously, the Vega Phroso Siltstone Member of the Sulphur Mountain Formation in British Columbia. This specimen co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tooth Socket
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 a ''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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homodont
In anatomy, a heterodont (from Greek, meaning 'different teeth') is an animal which possesses more than a single tooth morphology. Human dentition is heterodont and diphyodont as an example. In vertebrates, heterodont pertains to animals where teeth are differentiated into different forms. For example, members of the Synapsida generally possess incisors, canines ("dogteeth"), premolars, and molars. The presence of heterodont dentition is evidence of some degree of feeding and or hunting specialization in a species. In contrast, homodont or isodont dentition refers to a set of teeth that possess the same tooth morphology. In invertebrates, the term heterodont refers to a condition where teeth of differing sizes occur in the hinge plate, a part of the Bivalvia Bivalvia () or bivalves, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class (biology), class of aquatic animal, aquatic molluscs (marine and freshwater) that have laterally compr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Squamosal Bone
The squamosal is a skull bone found in most reptiles, amphibians, and birds. In fishes, it is also called the pterotic bone. In most tetrapods, the squamosal and quadratojugal bones form the cheek series of the skull. The bone forms an ancestral component of the dermal roof and is typically thin compared to other skull bones. The squamosal bone lies ventral to the temporal series and otic notch, and is bordered anteriorly by the postorbital. Posteriorly, the squamosal articulates with the quadrate and pterygoid bones. The squamosal is bordered anteroventrally by the jugal and ventrally by the quadratojugal. Function in reptiles In reptiles, the quadrate and articular bones of the skull articulate to form the jaw joint. The squamosal bone lies anterior to the quadrate bone. Anatomy in synapsids Non-mammalian synapsids In non-mammalian synapsids, the jaw is composed of four bony elements and referred to as a quadro-articular jaw because the joint is between the art ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Postorbital Bone
The ''postorbital'' is one of the bones in vertebrate skulls which forms a portion of the dermal skull roof and, sometimes, a ring about the orbit. Generally, it is located behind the postfrontal and posteriorly to the orbital fenestra. In some vertebrates, the postorbital is fused with the postfrontal to create a postorbitofrontal. Birds have a separate postorbital as an embryo An embryo ( ) is the initial stage of development for a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male sp ..., but the bone fuses with the frontal before it hatches. References * Roemer, A. S. 1956. ''Osteology of the Reptiles''. University of Chicago Press. 772 pp. Skull bones {{Vertebrate anatomy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supratemporal Fenestrae
Temporal fenestrae are openings in the Temple (anatomy), temporal region of the skull of some Amniote, amniotes, behind the Orbit (anatomy), orbit (eye socket). These openings have historically been used to track the evolution and affinities of reptiles. Temporal fenestrae are commonly (although not universally) seen in the fossilized skulls of dinosaurs and other sauropsids (the total group of reptiles, including birds). The major reptile group Diapsid, Diapsida, for example, is defined by the presence of two temporal fenestrae on each side of the skull. The infratemporal fenestra, also called the lateral temporal fenestra or lower temporal fenestra, is the lower of the two and is exposed primarily in lateral (side) view.The supratemporal fenestra, also called the upper temporal fenestra, is positioned above the other fenestra and is exposed primarily in dorsal (top) view. In some reptiles, particularly dinosaurs, the parts of the skull roof lying between the supratemporal fenestra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pineal Foramen
A parietal eye (third eye, pineal eye) is a part of the epithalamus in some vertebrates. The eye is at the top of the head; is photoreceptive; and is associated with the pineal gland, which regulates circadian rhythmicity and hormone production for thermoregulation. The hole that contains the eye is known as the pineal foramen or parietal foramen, because it is often enclosed by the parietal bones. The parietal eye was discovered by Franz Leydig, in 1872, from work with lizards. Discovery Franz Leydig, a professor of zoology at the University of Tübingen, dissected four species of European lizards—the slow worm ('' Anguis fragilis'') and three species of '' Lacerta''. in 1872; He found cup-like protrusions under the middles of their brains. He believed the protrusions to be glandular and called them frontal organs (German ''Stirnorgan''). In 1886, Walter Baldwin Spencer, an anatomist at the University of Oxford, reported the results of his dissection of 29 species of li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
