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Carusia
''Carusia'' is an extinct genus of lizards from the Late Cretaceous of Mongolia. It is a close relative of the family Xenosauridae, which includes living knob-scaled lizards. Fossils of the type and only species ''Carusia intermedia'' come from the late-Campanian age Barun Goyot Formation and have been found in the Flaming Cliffs, Ukhaa Tolgod, and Kheerman Tsav fossil localities. ''Carusia'' was first described in 1985 under the name ''Carolina intermedia'', but since the name ''Carolina'' was preoccupied by a genus of scarab beetles that had been named in 1880, it was renamed ''Carusia intermedia''. ''Carusia'' had initially been known from fragmentary skull material, complicating efforts to determine its evolutionary relationships with other lizards; it had variously been described as an indeterminate scincomorph, a xenosaurid, or some other type of autarchoglossan lizard convergent with xenosaurids. However, the discovery of 35 complete skulls in the 1990s, three of which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carusioidea
Carusioidea is a clade of lizards that includes the family Xenosauridae (knob-scaled lizards) from Central America and the extinct genus '' Carusia'' from the Late Cretaceous of Mongolia. It was named in 1998 after a sister-group relationship was found between ''Carusia'' and Xenosauridae. Phylogenetic analysis indicates that Carusioidea is the most basal clade within Anguimorpha. Features that help define Carusioidea include closely spaced orbits or eye sockets separated by fused frontal bones, a connection between the jugal and squamosal bones below the supratemporal arch, and a covering of bony osteoderms over the skull roof. Below is a cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to d ... showing the phylogenetic relationships of carusioids from Gao and Norell (1998): ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xenosauridae
Xenosauridae is a family of anguimorph lizards whose only living representative is the genus '' Xenosaurus'', which is native to Central America. Xenosauridae also includes the extinct genera '' Exostinus'' and '' Restes''. Also known as knob-scaled lizards, they have rounded, bumpy scales and osteoderms. Most living species prefer humid, rocky habitats, although they are widespread within their native regions, with some inhabiting semi-arid scrub environments. They are carnivorous or insectivorous, and give birth to live young. '' Shinisaurus'', the Chinese crocodile lizard, was once also regarded as a member of Xenosauridae, but most recent studies of the evolutionary relationships of anguimorphs consider ''Shinisaurus'' to be more closely related to monitor lizards and helodermatids than to ''Xenosaurus''. Xenosauridae is part of a larger clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, compose ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Knob-scaled Lizard
Xenosauridae is a family of anguimorph lizards whose only living representative is the genus ''Xenosaurus'', which is native to Central America. Xenosauridae also includes the extinct genera '' Exostinus'' and '' Restes''. Also known as knob-scaled lizards, they have rounded, bumpy scales and osteoderms. Most living species prefer humid, rocky habitats, although they are widespread within their native regions, with some inhabiting semi-arid scrub environments. They are carnivorous or insectivorous, and give birth to live young. ''Shinisaurus'', the Chinese crocodile lizard, was once also regarded as a member of Xenosauridae, but most recent studies of the evolutionary relationships of anguimorphs consider ''Shinisaurus'' to be more closely related to monitor lizards and helodermatids than to ''Xenosaurus''. Xenosauridae is part of a larger clade or evolutionary grouping called Carusioidea, which, in addition to xenosaurids, includes the extinct genus ''Carusia ''Carusia'' is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the Latin word for the white limestone known as chalk. The chalk of northern France and the white cliffs of south-eastern England date from the Cretaceous Period. Climate During the Late Cretaceous, the climate was warmer than present, although throughout the period a cooling trend is evident. The tropics became restricted to equatorial regions and northern latitudes experienced markedly more seasonal climatic conditions. Geography Due to plate tectonics, the Americas were gradually moving westward, causing the Atlantic Ocean to expand. The Western Interior Seaway divided North America into eastern and western halves; Appalachia and Laramidia. India maintained a northward course towards Asia. In the Southern Hemisphere, Australia and Ant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lizard Genera
Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia although some lizards are more closely related to these two excluded groups 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 such as the forest-dwelling ''Draco'' lizards are able to glide. They are often 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 being sit-and-wait predators; many smaller species eat insects, while the Komodo eats mammals as bi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cretaceous Lizards
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of the entire Phanerozoic. The name is derived from the Latin ''creta'', "chalk", which is abundant in the latter half of the period. It is usually abbreviated K, for its German translation ''Kreide''. The Cretaceous was a period with a relatively warm climate, resulting in high eustatic sea levels that created numerous shallow inland seas. These oceans and seas were populated with now-extinct marine reptiles, ammonites, and rudists, while dinosaurs continued to dominate on land. The world was ice free, and forests extended to the poles. During this time, new groups of mammals and birds appeared. During the Early Cretaceous, flowering plants appeared and began to rapidly diversify, becoming the dominant group of plants across the Earth by the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palatine Bone
In anatomy, the palatine bones () are two irregular bones of the facial skeleton in many animal species, located above the uvula in the throat. Together with the maxillae, they comprise the hard palate. (''Palate'' is derived from the Latin ''palatum''.) Structure The palatine bones are situated at the back of the nasal cavity between the maxilla and the pterygoid process of the sphenoid bone. They contribute to the walls of three cavities: the floor and lateral walls of the nasal cavity, the roof of the mouth, and the floor of the orbits. They help to form the pterygopalatine and pterygoid fossae, and the inferior orbital fissures. Each palatine bone somewhat resembles the letter L, and consists of a horizontal plate, a perpendicular plate, and three projecting processes—the pyramidal process, which is directed backward and lateral from the junction of the two parts, and the orbital and sphenoidal processes, which surmount the vertical part, and are separated by a dee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lacrimal Bone
The lacrimal bone is a small and fragile bone of the facial skeleton; it is roughly the size of the little fingernail. It is situated at the front part of the medial wall of the orbit. It has two surfaces and four borders. Several bony landmarks of the lacrimal bone function in the process of lacrimation or crying. Specifically, the lacrimal bone helps form the nasolacrimal canal necessary for tear translocation. A depression on the anterior inferior portion of the bone, the lacrimal fossa, houses the membranous lacrimal sac. Tears or lacrimal fluid, from the lacrimal glands, collect in this sac during excessive lacrimation. The fluid then flows through the nasolacrimal duct and into the nasopharynx. This drainage results in what is commonly referred to a runny nose during excessive crying or tear production. Injury or fracture of the lacrimal bone can result in posttraumatic obstruction of the lacrimal pathways. Structure Lateral or orbital surface The lateral or orbital surface i ... [...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 articular an ... [...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] |
Frontal Bone
The frontal bone is a bone in the human skull. The bone consists of two portions.''Gray's Anatomy'' (1918) These are the vertically oriented squamous part, and the horizontally oriented orbital part, making up the bony part of the forehead, part of the bony orbital cavity holding the eye, and part of the bony part of the nose respectively. The name comes from the Latin word ''frons'' (meaning " forehead"). Structure of the frontal bone The frontal bone is made up of two main parts. These are the squamous part, and the orbital part. The squamous part marks the vertical, flat, and also the biggest part, and the main region of the forehead. The orbital part is the horizontal and second biggest region of the frontal bone. It enters into the formation of the roofs of the orbital and nasal cavities. Sometimes a third part is included as the nasal part of the frontal bone, and sometimes this is included with the squamous part. The nasal part is between the brow ridges, and ends in ... [...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] |
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