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2012 In Archosaur Paleontology
The year 2012 in Archosaur paleontology was eventful. Archosaurs include the only living dinosaur group — birds — and the reptile crocodilians, plus all extinct dinosaurs, extinct crocodilian relatives, and pterosaurs. Archosaur palaeontology is the scientific study of those animals, especially as they existed before the Holocene Epoch began about 11,700 years ago. The year 2012 in paleontology included various significant developments regarding archosaurs. This article records new taxa of fossil archosaurs of every kind that have been described during the year 2012, as well as other significant discoveries and events related to paleontology of archosaurs that occurred in the year 2012. Pseudosuchians Research * The postcranial skeleton of ''Sebecus icaeorhinus'' is described by Diego Pol ''et al.'' (2012). * Skull anatomy of ''Dakosaurus'' and ''Plesiosuchus'' is described by Mark T. Young ''et al.'' (2012). * '' Kemkemia auditorei'', previously thought to be a theropo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archosaurs
Archosauria () is a clade of diapsids, with birds and crocodilians as the only living representatives. Archosaurs are broadly classified as reptiles, in the cladistic sense of the term which includes birds. Extinct archosaurs include non-avian dinosaurs, pterosaurs, and extinct relatives of crocodilians. Modern paleontologists define Archosauria as a crown group that includes the most recent common ancestor of living birds and crocodilians, and all of its descendants. The base of Archosauria splits into two clades: Pseudosuchia, which includes crocodilians and their extinct relatives, and Avemetatarsalia, which includes birds and their extinct relatives (such as non-avian dinosaurs and pterosaurs). Older definitions of the group Archosauria rely on shared morphological characteristics, such as an antorbital fenestra in the skull, serrated teeth, and an upright stance. Some extinct reptiles, such as proterosuchids and euparkeriids, possessed these features yet originate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crocodyliformes
Crocodyliformes is a clade of crurotarsan archosaurs, the group often traditionally referred to as "crocodilians". They are the first members of Crocodylomorpha to possess many of the features that define later relatives. They are the only pseudosuchians to survive the K-Pg extinction event. In 1988, Michael J. Benton and James M. Clark argued that all traditional names for well-known groups of animals should be restricted to their crown clades, that is, used only for natural groups comprising all living members of any given lineage. This posed a problem for the crocodilians, because the name Crocodylia, while used in various ways by various scientists, had always included not only living crocodilians but many of their extinct ancestors known only from the fossil record.Benton, M.J. and Clark, J.M. (1988). "Archosaur phylogeny and the relationships of the Crocodylia." Pp. 295–338 in Benton, M.J. (ed.), ''The phylogeny and classification of the Tetrapods, volume 1''. Oxford: Cl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apachesuchus
''Apachesuchus'' is an extinct genus of aetosaur from the Late Triassic of New Mexico. It is only known from several paramedian osteoderms discovered in Quay County in eastern New Mexico. This area belongs to the late Norian-age Quay Member of the Redonda Formation. Unique among aetosaurs, its osteoderms are nearly completely smooth, without strong pits or grooves. The left dorsal paramedian has a relatively high width-to-length ration (about 3.25), suggesting that ''Apachesuchus'' is a wide-bodied aetosaur within the clade Typothoracinae. The holotype and referred material of ''Apachesuchus'' were initially described by Heckert et al. (2001), who assigned them to the South American aetosaur ''Neoaetosauroides ''Neoaetosauroides'' is an extinct genus of primitive aetosaur. Its type and only species is ''N. engaeus''. Fossils have been found in Los Colorados Formation outcropping along the Sierra Morada River in the Ischigualasto-Villa Unión Basin in ...''.Heckert et al. (2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aetosaur
Aetosaurs () are heavily armored reptiles belonging to the extinct order Aetosauria (; from Greek, (aetos, "eagle") and (, "lizard")). They were medium- to large-sized omnivorous or herbivorous pseudosuchians, part of the branch of archosaurs more closely related to crocodilians than to birds and other dinosaurs. All known aetosaurs are restricted to the Late Triassic, and in some strata from this time they are among the most abundant fossil vertebrates. They have small heads, upturned snouts, erect limbs, and a body ornamented with four rows of plate-like osteoderms (bony scutes). Aetosaur fossil remains are known from Europe, North and South America, parts of Africa, and India. Since their armoured plates are often preserved and are abundant in certain localities, aetosaurs serve as important Late Triassic tetrapod index fossils. Many aetosaurs had wide geographic ranges, but their stratigraphic ranges were relatively short. Therefore, the presence of particular aetosaurs can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Santa Maria Formation
The Santa Maria Formation is a sedimentary rock formation found in Rio Grande do Sul, Brazil. It is primarily Carnian in age (Late Triassic), and is notable for its fossils of cynodonts, "rauisuchian" pseudosuchians, and early dinosaurs and other dinosauromorphs, including the herrerasaurid '' Staurikosaurus'', the basal sauropodomorphs ''Buriolestes'' and '' Saturnalia,'' and the lagerpetid ''Ixalerpeton''. The formation is named after the city of Santa Maria in the central region of Rio Grande do Sul, where outcrops were first studied. The Santa Maria Formation makes up the majority of the Santa Maria Supersequence, which extends through the entire Late Triassic. The Santa Maria Supersequence is divided into four geological sequences, separated from each other by short unconformities. The first two of these sequences (Pinheiros-Chiniquá and Santa Cruz sequences) lie entirely within the Santa Maria Formation, while the third (the Candelária sequence) is shared with the ov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aetobarbakinoides
''Aetobarbakinoides'' is an extinct genus of stagonolepidid aetosaur known from the Late Triassic of Rio Grande do Sul state, southern Brazil. Fossils have been found from the Santa Maria Supersequence of the late Carnian and early Norian stages, making ''Aetobarbakinoides'' one of the oldest aetosaurs. The type species, ''A. brasiliensis'', was named in 2012, and is notable for being described primarily by features of the vertebrae; most other aetosaurs are diagnosed by features in bony plates called osteoderms, which are by far the most common material. Although placed in a basal phylogenetic position among aetosaurs, ''Aetobarbakinoides'' is closely related to both desmatosuchines and typothoracisines, two derived clades of aetosaurs. Discovery ''Aetobarbakinoides'' is known only from the holotype specimen CPE2 168, a partially articulated partial postcranial skeleton which is housed at the Coleção Municipal in São Pedro do Sul. It was found near the city of São Ped ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eusuchia
Eusuchia is a clade of crocodylomorphs that first appeared in the Early Cretaceous with ''Hylaeochampsa''. Along with Dyrosauridae and Sebecosuchia, they were the only crocodyliformes who survived the K-T extinction. Since the other two clades died out 47 and 11 million years ago respectively, all living crocodilian species are eusuchians, as are many extinct forms. Definition Eusuchia was originally defined by Thomas Henry Huxley in 1875 as an apomorphy-based group, meaning that it was defined by shared characteristics rather than relations. These characteristics include pterygoid-bounded choanae and vertebrae which are procoelous (concave from the front and convex from the back). The possibility that these traits may have been convergently evolved in different groups of neosuchians rather than one lineage spurred some modern paleontologists to revise the group's definition to make it defined solely by relations. In 1999, Christopher Brochu redefined Eusuchia as "the last common ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aegyptosuchidae
Aegyptosuchidae is an extinct family of eusuchian crocodyliforms from the Cretaceous period of Africa. They are characterized by their large size and flat heads. The family includes two genera, '' Aegyptosuchus'' and '' Aegisuchus''. Aegyptosuchidae was originally established as the monotypic family name for '' Aegyptosuchus peyeri'' in 1933. Upon the discovery of the fellow aegyptosuchid '' Aegisuchus witmeri'' in 2012 by Holliday and Gardner, Aegyptosuchidae was phylogenetically defined as the least inclusive clade containing ''Aegisuchus witmeri'' and ''Aegyptosuchus peyeri'', so long as it does not include ''Alligator mississippiensis'' (American alligator), ''Bernissartia fagesii'', ''Crocodylus niloticus'' (Nile crocodile), ''Gavialis gangeticus'' (gharial), ''Hylaeochampsa vectiana'', or '' Susisuchus anatoceps''. Aegyptosuchidae belongs to the clade Eusuchia, and is proposed to be the sister clade to the crown group Crocodylia, which contains all extant (living) crocodili ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kem Kem Formation
The Kem Kem Group (commonly known as the Kem Kem beds) is a geological group in the Kem Kem region of eastern Morocco, whose strata date back to the Cenomanian stage of the Late Cretaceous. Its strata are subdivided into two geological formations, the lower Gara Sbaa Formation and the upper Douira Formation. It is exposed on an escarpment along the Algeria–Morocco border. The unit unconformably overlies Paleozoic marine units of Cambrian, Silurian and Devonian age, and is itself capped by limestone platform rock of Cenomanian-Turonian age. It primarily consists of deltaic deposits. The lower Gara Sbaa Formation primarily consists of fine and medium grained sandstone, while the Douira Formation consists of fining-upwards, coarse-to-fine grained sandstones intercalated with siltstones, variegated mudstones, and occasional thin gypsiferous evaporites. Dinosaur remains are among the fossils that have been recovered from the group.Weishampel, David B; ''et al.'' (2004). "Dinosau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aegisuchus
''Aegisuchus'' is an extinct monospecific genus of giant, flat-headed crocodyliform within the family Aegyptosuchidae. It was found in the Kem Kem Formation of southeast Morocco, which dates back to the Cenomanian age of the Late Cretaceous epoch. The type species ''Aegisuchus witmeri'' was named in 2012 by paleontologists Casey Holliday and Nicholas Gardner, who nicknamed it "Shieldcroc" for the shield-like shape of its skull. ''A. witmeri'' is known from a single partial skull including the braincase and skull roof. Description ''Aegisuchus'' is known only from a partial braincase and skull roof cataloged as ROM 54530. It is diagnosed by several autapomorphies, or unique features. At the center of the skull table is a raised and rough-surfaced boss on the parietal bone that is shaped like a circle. On either side of this boss are holes called dorsotemporal fenestrae, and the surrounding bone is relatively smooth. The quadrate bone in the temporal region of the skull has a rect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thailand
Thailand ( ), historically known as Siam () and officially the Kingdom of Thailand, is a country in Southeast Asia, located at the centre of the Indochinese Peninsula, spanning , with a population of almost 70 million. The country is bordered to the north by Myanmar and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the west by the Andaman Sea and the extremity of Myanmar. Thailand also shares maritime borders with Vietnam to the southeast, and Indonesia and India to the southwest. Bangkok is the nation's capital and largest city. Tai peoples migrated from southwestern China to mainland Southeast Asia from the 11th century. Indianised kingdoms such as the Mon, Khmer Empire and Malay states ruled the region, competing with Thai states such as the Kingdoms of Ngoenyang, Sukhothai, Lan Na and Ayutthaya, which also rivalled each other. European contact began in 1511 with a Portuguese diplomatic mission to Ayutthaya, w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleistocene
The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in 2009 by the International Union of Geological Sciences, the cutoff of the Pleistocene and the preceding Pliocene was regarded as being 1.806 million years Before Present (BP). Publications from earlier years may use either definition of the period. The end of the Pleistocene corresponds with the end of the last glacial period and also with the end of the Paleolithic age used in archaeology. The name is a combination of Ancient Greek grc, label=none, πλεῖστος, pleīstos, most and grc, label=none, καινός, kainós (latinized as ), 'new'. At the end of the preceding Pliocene, the previously isolated North and South American continents were joined by the Isthmus of Panama, causing Great American Interchang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
