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Alamodactylus
''Alamodactylus'' is an extinct genus of nyctosaurid pteranodontoid pterosaur known from the Late Cretaceous of Texas, southern United States. It contains a single species, ''Alamodactylus byrdi''. Discovery ''Alamodactylus'' is known solely from its holotype, SMU 76476, a partial left wing first described by Myers (2010).Myers, T.S., 2010, "Earliest occurrence of the Pteranodontidae (Archosauria: Pterosauria) in North America: New material from the Austin Group of Texas", ''Journal of Paleontology'' 84(6): 1071–1081 This specimen is crushed and consists of a left humerus, the distal end of the fourth wing metacarpal and the proximal end of the first wing phalanx of fourth digit. Other elements of the holotype first reported by Andres and Myers (2013) include a left proximal syncarpal, manual phalanx, and some fragments including four tapering processes that may represent skull bones, an articular surface that appears to be the mandible articulation of the right quadrate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nyctosaurus
''Nyctosaurus'' (meaning "night lizard" or "bat lizard") is a genus of nyctosaurid pterosaur from the Late Cretaceous period of what is now the Niobrara Formation of the mid-western United States, which, during the time ''Nyctosaurus'' was alive, was covered in an extensive shallow sea. Some remains belonging to a possible ''Nyctosaurus'' species called ''N.lamegoi'' have been found in Brazil, making ''Nyctosaurus'' more diverse. The genus ''Nyctosaurus'' has had numerous species referred to it, though how many of these may actually be valid requires further study. At least one species possessed an extraordinarily large antler-like cranial crest. ''Nyctosaurus'' was a mid-sized pterosaur that lived along the shores of the Niobrara Formation of the United States, which back then was within a large inland sea called the Western Interior Seaway. It has been suggested that it would have flown similar to modern-day soaring birds such as albatrosses, which consisted of flying very lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nyctosaurid
Nyctosauridae (meaning "night lizards" or "bat lizards") is a family of specialized soaring pterosaurs of the late Cretaceous Period of North America, Africa, and possibly Europe. It was named in 1889 by Henry Alleyne Nicholson and Richard Lydekker.Nicholson, H.A. and Lydekker, R. (1889). ''A manual of palaeontology for the use of students: with a general introduction on the principles of palæontology, Volume II''. Blackwood, 1889. Nyctosaurids are characterized by their lack of all but the wing finger. In most pterosaurs, the hand has four fingers, with the fourth elongated to support the wing, and the remaining three are usually small, clawed, and used in walking or climbing. The lack of functional fingers in nyctosaurids may suggest that they spent almost all of their time in the air, rarely walking on the ground. Nyctosaurids also possessed a distinctively enlarged crest for muscle attachment on their upper arm bone, or humerus, the ''deltopectoral crest'', hatchet sh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pteranodontoid
Pteranodontoidea (or pteranodontoids, from Greek meaning "toothless wings") is an extinct clade of ornithocheiroid pterosaurs from the Early to Late Cretaceous (early Valanginian to late Maastrichtian stages) of Asia, Africa, Europe, North America and South America. It was named by Alexander Wilhelm Armin Kellner in 1996. In 2003, Kellner defined the clade as a node-based taxon consisting of the last common ancestor of ''Anhanguera'', ''Pteranodon'' and all its descendants. The clade Ornithocheiroidea is sometimes considered to be the senior synonym of Pteranodontoidea, however it depends on its definition.Unwin, D. M., (2003): On the phylogeny and evolutionary history of pterosaurs. pp. 139-190. — ''in'' Buffetaut, E. & Mazin, J.-M., (eds.): ''Evolution and Palaeobiology of Pterosaurs''. Geological Society of London, Special Publications 217, London, 1-347 Brian Andres (2008, 2010, 2014) in his analyses, converts Ornithocheiroidea using the definition of Kellner (2003) to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pteranodon
''Pteranodon'' (); from Ancient Greek (''pteron'', "wing") and (''anodon'', "toothless") is a genus of pterosaur that included some of the largest known flying reptiles, with ''P. longiceps'' having a wingspan of . They lived during the late Cretaceous geological period of North America in present-day Kansas, Nebraska, Wyoming, South Dakota and Alabama. More fossil specimens of ''Pteranodon'' have been found than any other pterosaur, with about 1,200 specimens known to science, many of them well preserved with nearly complete skulls and articulated skeletons. It was an important part of the animal community in the Western Interior Seaway. ''Pteranodon'' was not a dinosaur. By definition, all dinosaurs belong to the group Dinosauria; ''Pteranodon'' belongs to the group Pterosauria. Nonetheless, ''Pteranodon'' is the most famous pterosaur, frequently featured in dinosaur media and strongly associated with dinosaurs by the general public. While not dinosaurs, pterosaurs such 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 a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Name Of A Biological Genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. '' Panthera leo'' (lion) and '' Panthera onca'' (jaguar) are two species within the genus ''Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants of an ancestral taxon are grouped together (i.e. phylogenetic analysis should clearly demo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autapomorphy
In phylogenetics, an autapomorphy is a distinctive feature, known as a derived trait, that is unique to a given taxon. That is, it is found only in one taxon, but not found in any others or outgroup taxa, not even those most closely related to the focal taxon (which may be a species, family or in general any clade). It can therefore be considered an apomorphy in relation to a single taxon. The word ''autapomorphy'', first introduced in 1950 by German entomologist Willi Hennig, is derived from the Greek words αὐτός, ''autos'' "self"; ἀπό, ''apo'' "away from"; and μορφή, ''morphḗ'' = "shape". Discussion Because autapomorphies are only present in a single taxon, they do not convey information about relationship. Therefore, autapomorphies are not useful to infer phylogenetic relationships. However, autapomorphy, like synapomorphy and plesiomorphy is a relative concept depending on the taxon in question. An autapomorphy at a given level may well be a synapomorphy a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pteranodontidae
The Pteranodontidae are a family of large pterosaurs of the Cretaceous Period of North America and Africa. The family was named in 1876 by Othniel Charles Marsh. Pteranodontids had a distinctive, elongated crest jutting from the rear of the head (most famously seen in ''Pteranodon'' itself). The spectacularly-crested '' Nyctosaurus'' is sometimes included in this family, though usually placed in its own family, the Nyctosauridae (Nicholson & Lydekker, 1889). Modern researchers differ in their use of the concept. S. Christopher Bennett and Alexander Kellner have concluded that ''Nyctosaurus'' was not a pteranodontid. In 1994 Bennett defined a clade Pteranodontidae, also including species of the Anhangueridae. However, this definition has not been accepted by other workers. Alexander Kellner, for example, named several additional species for specimens previously classified as ''Pteranodon'', and placed ''P. sternbergi'' in a distinct genus, ''Geosternbergia''. Kellner re-defined ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Million Years Ago
The abbreviation Myr, "million years", is a unit of a quantity of (i.e. ) years, or 31.556926 teraseconds. Usage Myr (million years) is in common use in fields such as Earth science and cosmology. Myr is also used with Mya (million years ago). Together they make a reference system, one to a quantity, the other to a particular place in a year numbering system that is ''time before the present''. Myr is deprecated in geology, but in astronomy ''Myr'' is standard. Where "myr" ''is'' seen in geology it is usually "Myr" (a unit of mega-years). In astronomy it is usually "Myr" (Million years). Debate In geology a debate remains open concerning the use of ''Myr'' (duration) plus ''Ma'' (million years ago) versus using only the term ''Ma''. In either case the term '' Ma'' is used in geology literature conforming to ISO 31-1 (now ISO 80000-3) and NIST 811 recommended practices. Traditional style geology literature is written The "ago" is implied, so that any such year number "X M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geological Timescale
The geologic time scale, or geological time scale, (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the process of relating strata to time) and geochronology (scientific branch of geology that aims to determine the age of rocks). It is used primarily by Earth scientists (including geologists, paleontologists, geophysicists, geochemists, and paleoclimatologists) to describe the timing and relationships of events in geologic history. The time scale has been developed through the study of rock layers and the observation of their relationships and identifying features such as lithologies, paleomagnetic properties, and fossils. The definition of standardized international units of geologic time is the responsibility of the International Commission on Stratigraphy (ICS), a constituent body of the International Union of Geological Sciences (IUGS), whose primary objective is to precisely define ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coniacian
The Coniacian is an age or stage in the geologic timescale. It is a subdivision of the Late Cretaceous Epoch or Upper Cretaceous Series and spans the time between 89.8 ± 1 Ma and 86.3 ± 0.7 Ma (million years ago). The Coniacian is preceded by the Turonian and followed by the Santonian. Stratigraphic definitions The Coniacian is named after the city of Cognac in the French region of Saintonge. It was first defined by French geologist Henri Coquand in 1857. The base of the Coniacian Stage is at the first appearance of the inoceramid bivalve species '' Cremnoceramus deformis erectus''. The official reference profile for the base (a GSSP) is located in Salzgitter-Salder, Lower Saxony, Germany. The top of the Coniacian (the base of the Santonian Stage) is defined by the appearance of the inoceramid bivalve '' Cladoceramus undulatoplicatus''. The Coniacian overlaps the regional Emscherian Stage of Germany, which is roughly coeval with the Coniacian and Santonian Stages. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Collin County
Collin County is located in the U.S. state of Texas. It is part of the Dallas- Fort Worth- Arlington metropolitan statistical area, and a small portion of the city of Dallas is in the county. At the 2020 United States census, the county's population is 1,064,465, making it the sixth-most populous county in Texas and the 43rd-largest county by population in the United States. Its county seat is McKinney. History Both the county and the county seat were named after Collin McKinney (1766-1861), one of the five men who drafted the Texas Declaration of Independence and the oldest of the 59 men who signed it. Geography According to the U.S. Census Bureau, the county has an area of , of which is land and (5.1%) is covered by water. Lakes * Lavon Lake Major highways Adjacent counties * Grayson County (north) * Fannin County (northeast) * Hunt County (east) * Rockwall County (southeast) * Dallas County (south) * Denton County (west) Communities Cities (shared with other coun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
