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Alamodactylus
''Alamodactylus'' is an extinct genus of pteranodontian 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). 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 as well as thin bones that do not taper and may be ossified tendons. ''Alamodactylus'' was first named by Brian Andres and Timothy S. Myers in 2013 and the type species is ''Alamodactylus byrdi''. The generic nam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pteranodontia
Pteranodontia is an extinct group of ornithocheiroid pterodactyloid pterosaurs. It lived during the Late Cretaceous (Turonian to Maastrichtian stages) of North America, South America, Europe and Africa. They were some of the most advanced pterosaurs, and possessed highly specialized cranial crests that may have served as sexual attraction, with males having a much larger crest. Classification Pteranodontia was originally named by Marsh in 1876. In 2003, it was given a phylogenetic definition by David Unwin as the common ancestor of ''Pteranodon'' and ''Nyctosaurus'' plus all its descendants. Though Marsh had originally named this group based on the shared absence of teeth in those species, most analyses show that all of the traditional "ornithocheiroid" pterosaurs are also members of this clade. Below is a cladogram showing the phylogenetic placement of this group from Andres and Myers (2013). In 2018, Longrich, Martill, and Andres revisited the classification and proposed a di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nyctosaurus
''Nyctosaurus'' (meaning "night 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, though it likely belongs to a different genus '' Simurghia''. 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 fl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pteranodon
''Pteranodon'' (; from and ) is a genus of pterosaur that included some of the largest known flying reptiles, with ''P. longiceps'' having a wingspan of over . 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. When the first fossils of ''Pteranodon'' were found, they were assigned to toothed pterosaur genera, ''Ornithocheirus'' and ''Pterodactylus''. In 1876, Othniel Charles Marsh recognised it as a genus of its own, making particular note of its complete lack of teeth, which at the time was unique among pterosaurs. Over the decades, multiple species would be assigned to ''Pteranodon'', though today, o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the more recent 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, Aus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Name Of A Biological Genus
Genus (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. 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 demonstrate both monophyly and validity as a separate lineage). # re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foramen
In anatomy and osteology, a foramen (; : foramina, or foramens ; ) is an opening or enclosed gap within the dense connective tissue (bones and deep fasciae) of extant and extinct amniote animals, typically to allow passage of nerves, artery, arteries, veins or other soft tissue structures (e.g. muscle tendon) from one body compartment to another. Skull The skulls of vertebrates have foramina through which nerves, arteries, veins, and other structures pass. The human skull has many foramina, collectively referred to as the cranial foramina. Spine Within the vertebral column (spine) of vertebrates, including the Human vertebral column, human spine, each bone has an opening at both its top and bottom to allow nerves, arteries, veins, etc. to pass through. Other * Apical foramen, the hole at the tip of the root of a tooth * Foramen ovale (heart), a hole between the venous and arterial sides of the fetal heart * Vertebra#Cervical vertebrae, Transverse foramen, one of a pair ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autapomorphy
In phylogenetics, an autapomorphy is a distinctive feature, known as a Synapomorphy, 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 (cladistics), outgroup taxa, not even those most closely related to the focal taxon (which may be a species, family (biology), family or in general any clade). It can therefore be considered as an apomorphy in relation to a single taxon. The word ''autapomorphy'', introduced in 1950 by German entomology, entomologist Willi Hennig, is derived from the Greek language, 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 ta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pteranodontidae
The Pteranodontidae are a Family (biology), family of large pterosaurs from the Late Cretaceous of North America and possibly other continents including Europe 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 Ornithocheiromorpha. 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. sternbe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Million Years Ago
Million years ago, abbreviated as Mya, Myr (megayear) or Ma (megaannum), is a unit of time equal to (i.e. years), or approximately 31.6 teraseconds. Usage Myr is in common use in fields such as Earth science and cosmology. Myr is also used with Mya or Ma. Together they make a reference system, one to a quantity, the other to a particular point 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 ''Mya'' (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 s ... [...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 (a 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 standardised international units of geological 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 de ... [...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 magn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Collin County
Collin County is a county in the northern part of 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 was 1,064,465, making it Texas's sixth-most populous county and the 43rd-largest county by population in the United States. Its county seat is McKinney. History Native Americans around Collin County and North Texas included the Caddo, Comanche, Cherokee, Delaware, Kickapoo, and Tonkawa. Several Native American sites have been found, including around Lavon Lake and Sister Grove Creek. 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. Civil War Like many counties in North Texas, Collin County voted against secession from the United States. This is mainly due to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
