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Alligator Hailensis
''Alligator hailensis'', or Haile alligator, is a large, extinct species of ''Alligator'' known from the early Pleistocene of Florida. It is named after the town of Haile, Florida, where it was found. Its age and skeletal morphology is intermediate between the geologically older ''Alligator mefferdi'' and the modern American alligator, making it a transitional fossil.PBDB. "Alligator Hailensis Stout 2020 (Alligator)." PBDBpaleobiodb.org/classic/basicTaxonInfo?taxon_no=427868/ref> History and naming The remains of ''Alligator hailensis'' were found in the Haile 7C and 7G fossil sites, late Blancan assemblages from Alachua County, Florida, likely representing water-filled sinkholes that were covered in sediments. These fossil localities yielded a minimum of forty-three individual alligators, possibly even more, bridging the gap between species from the Pliocene and the modern American alligator. Out of these, specimen UF 224688, a complete skull with mandible and assorted postcrani ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Pleistocene
The Early Pleistocene is an unofficial sub-epoch in the international geologic timescale in chronostratigraphy, being the earliest division of the Pleistocene Epoch within the ongoing Quaternary Period. It is currently estimated to span the time between 2.580 ± 0.005 Ma (million years ago) and 0.773 ± 0.005 Ma. The term Early Pleistocene applies to both the Gelasian Age (to 1.800 ± 0.005 Ma) and the Calabrian Age. While the Gelasian and the Calabrian have officially been defined by the International Union of Geological Sciences (IUGS) to effectively constitute the Early Pleistocene, the succeeding Chibanian and Tarantian ages have yet to be ratified. These proposed ages are unofficially termed the Middle Pleistocene and Late Pleistocene The Late Pleistocene is an unofficial Age (geology), age in the international geologic timescale in chronostratigraphy, also known as Upper Pleistocene from a Stratigraphy, stratigraphic perspective. It is intended to be the fourth div ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Premaxilla
The premaxilla (or praemaxilla) is one of a pair of small cranial bones at the very tip of the upper jaw of many animals, usually, but not always, bearing teeth. In humans, they are fused with the maxilla. The "premaxilla" of therian mammal has been usually termed as the incisive bone. Other terms used for this structure include premaxillary bone or ''os premaxillare'', intermaxillary bone or ''os intermaxillare'', and Goethe's bone. Human anatomy In human anatomy, the premaxilla is referred to as the incisive bone (') and is the part of the maxilla which bears the incisor teeth, and encompasses the anterior nasal spine and alar region. In the nasal cavity, the premaxillary element projects higher than the maxillary element behind. The palatal portion of the premaxilla is a bony plate with a generally transverse orientation. The incisive foramen is bound anteriorly and laterally by the premaxilla and posteriorly by the palatine process of the maxilla. It is formed from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alligator Olseni
''Alligator olseni'' (common name Olsen's Alligator, named after Russel Olsen) is an extinct species of alligator. They lived in the Early Miocene period, around 20.4–15.97 million years ago and possibly earlier. Their range was principally in what is now known as Florida, United States, and possibly extending into southeastern Texas. References Alligatoridae Miocene reptiles of North America Fossil taxa described in 1942 {{paleo-archosaur-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alligator Mcgrewi
''Alligator mcgrewi'' is an extinct species of alligator described by K.P. Schmidt. They lived in the Early Miocene period,Alligator mcgrewi Schmidt, 1941 in Paleobiology Database (2018). The Paleobiology Database. Checklist dataset https://doi.org/10.15468/zzoyxi accessed via GBIF.org on 2020-11-05. and their range was principally in what is now Nebraska, United States. Measurements The average measurements for the skull of ''A. mcgrewi'' are 145 x 96 in millimeters. Based on the length, the estimated body mass Mass is an intrinsic property of a body. It was traditionally believed to be related to the quantity of matter in a physical body, until the discovery of the atom and particle physics. It was found that different atoms and different elementar ... was 3 kg. References Alligatoridae Miocene reptiles of North America Fossil taxa described in 1941 Taxa named by Karl Patterson Schmidt {{paleo-archosaur-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alligator Prenasalis
''Alligator prenasalis'' is an extinct species of alligator from the Late Eocene period. It is well known, with many fossils having been collected from the Chadron and Brule Formations in South Dakota. The species was first named in 1904, but was originally classified as a crocodile in the genus ''Crocodilus''. It was reassigned to the genus ''Alligator'' in 1918 on the basis of more complete material. It is the earliest known member of the genus ''Alligator''. Taxonomy Junior synonyms Several species of extinct alligatorines have been considered junior synonyms of ''A. prenasalis''. These include ''Caimanoidea visheri'', named by paleontologist Maurice Mehl in 1916 from fragmentary material, and ''Allognathosuchus riggsi'', named in 1931 from a single piece of a lower jaw. Both were considered synonymous with the species in 1972 by paleontologist D.W. Higgins. Mehl used two alternate spellings of ''Caimanoidea'' in his 1916 paper: ''Caimanoideus'' and ''Caimanoeda''. Because t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anagenesis
Anagenesis is the gradual evolution of a species that continues to exist as an interbreeding population. This contrasts with cladogenesis, which occurs when there is branching or splitting, leading to two or more lineages and resulting in separate species. Anagenesis does not always lead to the formation of a new species from an ancestral species. When speciation does occur as different lineages branch off and cease to interbreed, a core group may continue to be defined as the original species. The evolution of this group, without extinction or species selection, is anagenesis. Hypotheses One hypothesis is that during the speciation event in anagenetic evolution, the original populations will increase quickly, and then rack up genetic variation over long periods of time by mutation and recombination in a stable environment. Other factors such as selection or genetic drift will have such a significant effect on genetic material and physical traits that a species can be acknow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Midwest
The Midwestern United States, also referred to as the Midwest or the American Midwest, is one of four census regions of the United States Census Bureau (also known as "Region 2"). It occupies the northern central part of the United States. It was officially named the North Central Region by the Census Bureau until 1984. It is between the Northeastern United States and the Western United States, with Canada to the north and the Southern United States to the south. The Census Bureau's definition consists of 12 states in the north central United States: Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, North Dakota, Ohio, South Dakota, and Wisconsin. The region generally lies on the broad Interior Plain between the states occupying the Appalachian Mountain range and the states occupying the Rocky Mountain range. Major rivers in the region include, from east to west, the Ohio River, the Upper Mississippi River, and the Missouri River. The 2020 United ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nebraska
Nebraska () is a state in the Midwestern region of the United States. It is bordered by South Dakota to the north; Iowa to the east and Missouri to the southeast, both across the Missouri River; Kansas to the south; Colorado to the southwest; and Wyoming to the west. It is the only triply landlocked U.S. state. Indigenous peoples, including Omaha, Missouria, Ponca, Pawnee, Otoe, and various branches of the Lakota ( Sioux) tribes, lived in the region for thousands of years before European exploration. The state is crossed by many historic trails, including that of the Lewis and Clark Expedition. Nebraska's area is just over with a population of over 1.9 million. Its capital is Lincoln, and its largest city is Omaha, which is on the Missouri River. Nebraska was admitted into the United States in 1867, two years after the end of the American Civil War. The Nebraska Legislature is unlike any other American legislature in that it is unicameral, and its members are elected ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chinese Alligator
The Chinese alligator (; ), also known as the Yangtze alligator (), China alligator, or historically the muddy dragon, is a crocodilian endemic to China. It and the American alligator (''A. mississippiensis'') are the only living species in the genus ''Alligator'' of the family Alligatoridae. Dark gray or black in color with a fully armored body, the Chinese alligator grows to in length and weighs as an adult. It brumates in burrows in winter and is nocturnal in summer. Mating occurs in early summer, with females most commonly producing 20–30 eggs, which are smaller than those of any other crocodilian. The species is an opportunistic feeder, primarily eating fish and invertebrates. A vocal species, adults bellow during the mating season and young vocalize to communicate with their parents and other juveniles. Captive specimens have reached age 70, and wild specimens can live past 50. Living in bodies of fresh water, the Chinese alligator's range is restricted to six regions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Splenial
The splenial is a small bone in the lower jaw of reptiles, amphibians and birds, usually located on the lingual side (closest to the tongue) between the angular and surangular The suprangular or surangular is a jaw bone found in most land vertebrates, except mammals. Usually in the back of the jaw, on the upper edge, it is connected to all other jaw bones: dentary, angular, splenial and articular The articular bone i ....Watson, D. M. S. (1912). LXVII.—On some reptilian lower jaws. Journal of Natural History, 10(60), 573-587. References Vertebrate anatomy {{Vertebrate anatomy-stub ... [...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] |
Pterygoid Bone
The pterygoid is a paired bone forming part of the palate of many vertebrates, behind the 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 ''pa ...s. It is a flat and thin lamina, united to the medial side of the pterygoid process of the sphenoid bone, and to the perpendicular lamina of the palatine bone. Bones of the head and neck {{musculoskeletal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
