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Saichangurvel
''Saichangurvel'' (meaning "beautiful lizard" in Mongolian) is an extinct genus of iguanian lizards from the Late Cretaceous of Mongolia. It is a member of a clade called Gobiguania, an exclusively Late Cretaceous group of iguanian lizards that was likely endemic to the Gobi Desert. The type species, ''Saichangurvel davidsoni'', was named by paleontologists Jack Conrad and Mark Norell of the American Museum of Natural History in 2007. It is known from a single nearly complete and fully articulated skeleton called IGM 3/858, which was found eroding from a block of sandstone during a thunderstorm at a fossil locality called Ukhaa Tolgod. IGM 3/858 comes from the Djadochta Formation, which is between 75 and 71 million years in age. Just as it is today, the Gobi was a desert during the Cretaceous. IGM 3/858 may have died in a collapsing sand dune, the rapid burial preserving its skeleton in pristine condition. ''Saichangurvel'' has a lightly built skull with a short snout and larg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gobiguania
Gobiguania is an extinct clade of iguanian lizards from the Late Cretaceous. All known gobiguanians are endemic to the Gobi Desert of Mongolia. Gobiguania was given a phylogenetic definition by Jack Conrad and Mark Norell in 2007 as all taxa more closely related to '' Anchaurosaurus gilmorei'' than to '' Iguana iguana'' (the green iguana), '' Crotaphytus collaris'' (the common collared lizard), or '' Agama agama'' (the common agama). According to Conrad and Norell's phylogenetic analysis, Gobiguania includes ''Anchaurosaurus'' as well as several other Late Cretaceous lizards such as '' Ctenomastax'', ''Temujinia'', ''Saichangurvel'', and '' Zapsosaurus''. A phylogenetic analysis published in 2012 indicated that three other lizard genera — '' Igua'', '' Isodontosaurus'', and ''Polrussia ''Polrussia'' is an extinct genus of iguanian lizards dating to the Late Cretaceous epoch, found in what is now Mongolia. It belongs to a group of extinct iguanians called Gobiguania that was e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temujinia
Gobiguania is an extinct clade of iguanian lizards from the Late Cretaceous. All known gobiguanians are endemic to the Gobi Desert of Mongolia. Gobiguania was given a phylogenetic definition by Jack Conrad and Mark Norell Mark Allen Norell (born July 26, 1957) is an American paleontologist, acknowledged as one of the most important living vertebrate paleontologists. He is currently the chairman of paleontology and a research associate at the American Museum of Na ... in 2007 as all taxa more closely related to '' Anchaurosaurus gilmorei'' than to '' Iguana iguana'' (the green iguana), '' Crotaphytus collaris'' (the common collared lizard), or '' Agama agama'' (the common agama). According to Conrad and Norell's phylogenetic analysis, Gobiguania includes ''Anchaurosaurus'' as well as several other Late Cretaceous lizards such as '' Ctenomastax'', '' Temujinia'', '' Saichangurvel'', and '' Zapsosaurus''. A phylogenetic analysis published in 2012 indicated that three other lizard ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Djadochta Formation
The Djadochta Formation (sometimes transcribed and also known as Djadokhta, Djadokata, or Dzhadokhtskaya) is a highly fossiliferous geological formation situated in Central Asia, Gobi Desert, dating from the Late Cretaceous period, about 75 million to 71 million years ago. The type locality is the Bayn Dzak locality, famously known as the Flaming Cliffs. Dinosaur, mammal, and other reptile remains are among the fossils that have been recovered from the formation. Excavation history The Djadochta Formation was first documented and explored—though only a single locality—during paleontological expeditions of the American Museum of Natural History in 1922–1925, which were part of the Central Asiatic Expeditions. The expeditions were led by Roy Chapman Andrews, in company of Walter Willis Granger as chief paleontologist and field team. The team did extensive exploration at the Bayn Dzak (formerly Shabarakh Usu) region, which they nicknamed Flaming Cliffs given that at sunset th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iguania
Iguania is an infraorder of squamate reptiles that includes iguanas, chameleons, agamids, and New World lizards like anoles and phrynosomatids. Using morphological features as a guide to evolutionary relationships, the Iguania are believed to form the sister group to the remainder of the Squamata, which comprise nearly 11,000 named species, roughly 2000 of which are iguanians. However, molecular information has placed Iguania well within the Squamata as sister taxa to the Anguimorpha and closely related to snakes. The order has been under debate and revisions after being classified by Charles Lewis Camp in 1923 due to difficulties finding adequate synapomorphic morphological characteristics. Most Iguanias are arboreal but there are several terrestrial groups. They usually have primitive fleshy, non-prehensile tongues, although the tongue is highly modified in chameleons. The group has a fossil record that extends back to the Early Jurassic (the oldest known member is '' B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iguania
Iguania is an infraorder of squamate reptiles that includes iguanas, chameleons, agamids, and New World lizards like anoles and phrynosomatids. Using morphological features as a guide to evolutionary relationships, the Iguania are believed to form the sister group to the remainder of the Squamata, which comprise nearly 11,000 named species, roughly 2000 of which are iguanians. However, molecular information has placed Iguania well within the Squamata as sister taxa to the Anguimorpha and closely related to snakes. The order has been under debate and revisions after being classified by Charles Lewis Camp in 1923 due to difficulties finding adequate synapomorphic morphological characteristics. Most Iguanias are arboreal but there are several terrestrial groups. They usually have primitive fleshy, non-prehensile tongues, although the tongue is highly modified in chameleons. The group has a fossil record that extends back to the Early Jurassic (the oldest known member is '' B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pineal Foramen
A parietal eye, also known as a third eye or pineal eye, is a part of the epithalamus present in some vertebrates. The eye is located at the top of the head, is photoreceptive and is associated with the pineal gland, regulating circadian rhythmicity and hormone production for thermoregulation. The hole in the head which contains the eye is known as a pineal foramen or parietal foramen, since it is often enclosed by the parietal bones. Presence in various animals The parietal eye is found in the tuatara, most lizards, frogs, salamanders, certain bony fish, sharks, and lampreys. It is absent in mammals, but was present in their closest extinct relatives, the therapsids, suggesting it was lost during the course of the mammalian evolution due to it being useless in endothermic animals. It is also absent in the ancestrally endothermic ("warm-blooded") archosaurs such as birds. The parietal eye is also lost in ectothermic ("cold-blooded") archosaurs like crocodilians, and in turtles, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caniniform
In mammalian oral anatomy, the canine teeth, also called cuspids, dog teeth, or (in the context of the upper jaw) fangs, eye teeth, vampire teeth, or vampire fangs, are the relatively long, pointed teeth. They can appear more flattened however, causing them to resemble incisors and leading them to be called ''incisiform''. They developed and are used primarily for firmly holding food in order to tear it apart, and occasionally as weapons. They are often the largest teeth in a mammal's mouth. Individuals of most species that develop them normally have four, two in the upper jaw and two in the lower, separated within each jaw by incisors; humans and dogs are examples. In most species, canines are the anterior-most teeth in the maxillary bone. The four canines in humans are the two maxillary canines and the two mandibular canines. Details There are generally four canine teeth: two in the upper (maxillary) and two in the lower (mandibular) arch. A canine is placed laterally t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 descendants, nor does it show how much they have changed, so many differing evolutionary trees can be consistent with the same cladogram. A cladogram uses lines that branch off in different directions ending at a clade, a group of organisms with a last common ancestor. There are many shapes of cladograms but they all have lines that branch off from other lines. The lines can be traced back to where they branch off. These branching off points represent a hypothetical ancestor (not an actual entity) which can be inferred to exhibit the traits shared among the terminal taxa above it. This hypothetical ancestor might then provide clues about the order of evolution of various features, adaptation, and other evolutionary narratives about ance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phylogenetic
In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups of organisms. These relationships are determined by Computational phylogenetics, phylogenetic inference methods that focus on observed heritable traits, such as DNA sequences, protein amino acid sequences, or morphology. The result of such an analysis is a phylogenetic tree—a diagram containing a hypothesis of relationships that reflects the evolutionary history of a group of organisms. The tips of a phylogenetic tree can be living taxa or fossils, and represent the "end" or the present time in an evolutionary lineage. A phylogenetic diagram can be rooted or unrooted. A rooted tree diagram indicates the hypothetical common ancestor of the tree. An unrooted tree diagram (a network) makes no assumption about the ancestral line, and does ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Huehuecuetzpalli Mixtecus
''Huehuecuetzpalli mixtecus'' is an extinct lizard from the Early Cretaceous (specifically the middle to late Aptian stage) Tlayúa Formation in Tepexi de Rodríguez, Central Mexico. Although it is not the oldest known lizard, ''Huehuecuetzpalli'' may be amongst the most basal members of Squamata (the group that includes lizards and snakes), making it an important taxon in understanding the origins of squamates. The generic name comes from the Nahuatl words ''huehuetl'' ("the ancient") and ''cuetzpalli'' ("lizard"), while the specific name refers to the La Mixteca region. Description Unique characteristics (autapomorphies) of ''Huehuecuetzpalli'' include a long pair of premaxilla bones at the tip of the upper jaw that contributes to an elongated snout and the apparent retraction of the external nares or nostril openings. At the top of the skull, a small rounded postfrontal and a hole called the parietal foramen between the junction of the frontal bone and the parietal bone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hoyalacerta Sanzi
''Hoyalacerta'' is an extinct genus of lizard known from the type species ''Hoyalacerta sanzi'', which is from the Early Cretaceous Las Hoyas fossil site in Spain. ''Hoyalacerta'' was named in 1999 and is considered either a member of the group Iguania or a stem squamate, meaning that it lies outside the squamate crown group that includes all living lizards and snakes. ''Hoyalacerta'' is a small lizard with an elongated body and short limbs. It is thought to have spent most of its time on the ground. Several other lizards are also known from Las Hoyas, including ''Meyasaurus ''Meyasaurus'' is an extinct genus of Teiid lizard known from the Barremian of Spain and the Isle of Wight, UK. Four species are known from Spain, from the La Huérguina, Camarillas, and La Pedrera de Rúbies Formations while an indeterminate ...'' (thought to have lived near the water), '' Scandensia'' (thought to be a climber), and '' Jucaraseps'' (which, like ''Hoyalacerta'', probably lived on the gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fontanelle
A fontanelle (or fontanel) (colloquially, soft spot) is an anatomical feature of the infant human skull comprising soft membranous gaps ( sutures) between the cranial bones that make up the calvaria of a fetus or an infant. Fontanelles allow for stretching and deformation of the neurocranium both during birth and later as the brain expands faster than the surrounding bone can grow. Premature complete ossification of the sutures is called craniosynostosis. After infancy, the anterior fontanelle is known as the bregma. Structure An infant's skull consists of five main bones: two frontal bones, two parietal bones, and one occipital bone. These are joined by fibrous sutures, which allow movement that facilitates childbirth and brain growth. * Posterior fontanelle is triangle-shaped. It lies at the junction between the sagittal suture and lambdoid suture. At birth, the skull features a small posterior fontanelle with an open area covered by a tough membrane, where the two pariet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
