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Wakayama Soryu
''Megapterygius'' (meaning "large wing") is an extinct genus of mosasaurine mosasaur from the Late Cretaceous Toyajo Formation (Hasegawa Muddy Sandstone Member) of Japan. The genus contains a single species, ''M. wakayamaensis'', known from an almost complete skeleton. Discovery and naming The ''Megapterygius'' holotype specimen, Wakayama Prefectural Museum of Natural History, WMNH-Ge-1140240002, was discovered in 2006 by Akihiro Misaki in sediments of the Hasegawa Muddy Sandstone Member of the Toyajo Formation near the peak of Mt. Toyajo in Wakayama Prefecture of Japan. The specimen consists of a partial skull, a complete cervical and dorsal vertebral series with more than 40 vertebrae, ribs, both front flippers, and the left hind flipper. In 2023, Konishi ''et al.'' Species description, described ''Megapterygius wakayamaensis'' as a new genus and species of mosasaurine based on these fossil remains. The Genus, generic name, "''Megapterygius''", is derived from the Ancient Gre ... [...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] |
Anatomical Terms Of Location
Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position provides a definition of what is at the front ("anterior"), behind ("posterior") and so on. As part of defining and describing terms, the body is described through the use of anatomical planes and axes. The meaning of terms that are used can change depending on whether a vertebrate is a biped or a quadruped, due to the difference in the neuraxis, or if an invertebrate is a non-bilaterian. A non-bilaterian has no anterior or posterior surface for example but can still have a descriptor used such as proximal or distal in relation to a body part that is nearest to, or furthest from its middle. International organisations have determined vocabularies that are often used as standards for subdisciplines of anatomy. For example, '' Termi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cladogram
A cladogram (from Greek language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, 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 e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phylogenetic Analyses
In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as Computational phylogenetics, phylogenetic inference. It infers the relationship among organisms based on empirical data and observed heritable traits of DNA sequences, protein amino acid sequences, and Morphology (biology), morphology. The results are a phylogenetic tree—a diagram depicting the hypothesis, hypothetical relationships among the organisms, reflecting their inferred evolutionary history. The tips of a phylogenetic tree represent the observed entities, which can be living Taxon, taxa or fossils. A phylogenetic diagram can be rooted or unrooted. A rooted tree diagram indicates the hypothetical common ancestor of the taxa represented on the tree. An unrooted tree diagram (a network) makes no assumption about directionality of character state transformation, and does not show the origin or "root" of the taxa in questi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plotosaurus
''Plotosaurus'' ("swimmer lizard") is an extinct genus of large mosasaurs which lived during the Upper Cretaceous (Maastrichtian) in what is now North America. The taxon was initially described by University of California, Berkeley, Berkeley paleontologist Charles Lewis Camp in 1942 from several more or less complete fossil specimens discovered in California, USA. Originally named as ''Kolposaurus'' (meaning "bay lizard"), it was changed to ''Plotosaurus'' in 1951 when Camp discovered that the name had already been assigned to a type of nothosaur. Two species were historically assigned to the genus, but since 2008, only ''P. bennisoni'' has been recognized as Valid name (zoology), valid. Unlike other mosasaurids, ''Plotosaurus'' possesses a morphology Convergent evolution, converging with those of ichthyosaurs, suggesting a much more advanced swimming adaptation than some of its close relatives. It is these same adaptations that have led to its classification in a rather derived p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mosasaurus
''Mosasaurus'' (; "lizard of the Meuse (river), Meuse River") is the type genus (defining example) of the mosasaurs, an extinct group of aquatic Squamata, squamate reptiles. It lived from about 82 to 66 million years ago during the Campanian and Maastrichtian Stage (stratigraphy), stages of the Late Cretaceous. The genus was one of the first Mesozoic marine reptiles known to science—the first fossils of ''Mosasaurus'' were found as skulls in a chalk quarry near the Dutch city of Maastricht in the late 18th century, and were initially thought to be crocodiles or whales. One skull discovered around 1780 was famously nicknamed the "great animal of Maastricht". In 1808, naturalist Georges Cuvier concluded that it belonged to a giant marine lizard with similarities to monitor lizards but otherwise unlike any known living animal. This concept was revolutionary at the time and helped support the then-developing ideas of extinction. Cuvier did not designate a scientific name for the an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rikisaurus
''Moanasaurus'' (From Māori ''moana'' "sea" and Greek ''sauros'' "lizard"; meaning "Sea Lizard") was a genus of mosasaur from the Late Cretaceous period. Its fossil remains have been discovered in the North Island of New Zealand. ''Moanasaurus'' was a very large mosasaurine known originally from holotype CD43, a disarticulated skull, vertebrae, ribs and flipper bones. The skull measures in length, which shows that ''Moanasaurus'' was one of the largest in the subfamily of Mosasaurinae. Researchers argue that some Antarctic ''Mosasaurus'' remains (including a "large, fragmentary skull") may be attributed to this genus. Two additional species have been named, "Moanasaurus hobetsuensis" (originally named ''Mosasaurus hobetsuensis'') and " Moanasaurus longirostris", but these are nomina nuda because they were named in a PhD thesis. The same thesis argued that ''Mosasaurus flemingi'' is a junior synonym of ''Moanasaurus mangahouangae''. See also *List of dinosaurs and other Mesozo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sister Taxon
In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and taxon B are sister groups to each other. Taxa A and B, together with any other extant or extinct descendants of their most recent common ancestor (MRCA), form a monophyletic group, the clade AB. Clade AB and taxon C are also sister groups. Taxa A, B, and C, together with all other descendants of their MRCA form the clade ABC. The whole clade ABC is itself a subtree of a larger tree which offers yet more sister group relationships, both among the leaves and among larger, more deeply rooted clades. The tree structure shown connects through its root to the rest of the universal tree of life. In cladistic standards, taxa A, B, and C may represent specimens, species, genera, or any other taxonomic units. If A and B are at the same taxonomic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mosasauridae
Mosasaurs (from Latin ''Mosa'' meaning the 'Meuse', and Greek ' meaning 'lizard') are an extinct group of large aquatic reptiles within the family Mosasauridae that lived during the Late Cretaceous. Their first fossil remains were discovered in a limestone quarry at Maastricht on the Meuse in 1764. They belong to the order Squamata, which includes lizards and snakes. During the last 20 million years of the Cretaceous period (Turonian–Maastrichtian ages), with the extinction of the ichthyosaurs and pliosaurs, mosasaurids became the dominant marine predators. They themselves became extinct as a result of the K-Pg event at the end of the Cretaceous period, about 66 million years ago. Description Mosasaurs breathed air, were powerful swimmers, and were well-adapted to living in the warm, shallow inland seas prevalent during the Late Cretaceous period. Mosasaurs were so well adapted to this environment that they most likely gave birth to live young, rather than returning to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Squamate
Squamata (, Latin ''squamatus'', 'scaly, having scales') is the largest Order (biology), order of reptiles; most members of which are commonly known as Lizard, lizards, with the group also including Snake, snakes. With over 11,991 species, it is also the second-largest order of Neontology, extant (living) vertebrates, after the Perciformes, perciform fish. Squamates are distinguished by their skins, which bear horny scale (zoology), scales or shields, and must periodically engage in molting. They also possess movable quadrate bones, making possible movement of the Maxilla, upper jaw relative to the neurocranium. This is particularly visible in snakes, which are able to open their mouths very widely to accommodate comparatively large prey. Squamates are the most variably sized living reptiles, ranging from the Sphaerodactylus ariasae, dwarf gecko (''Sphaerodactylus ariasae'') to the reticulated python (''Malayopython reticulatus''). The now-Extinction, extinct mosasaurs reached ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megapterygius Wakayamaensis
''Megapterygius'' (meaning "large wing") is an extinct genus of mosasaurine mosasaur from the Late Cretaceous Toyajo Formation (Hasegawa Muddy Sandstone Member) of Japan. The genus contains a single species, ''M. wakayamaensis'', known from an almost complete skeleton. Discovery and naming The ''Megapterygius'' holotype specimen, WMNH-Ge-1140240002, was discovered in 2006 by Akihiro Misaki in sediments of the Hasegawa Muddy Sandstone Member of the Toyajo Formation near the peak of Mt. Toyajo in Wakayama Prefecture of Japan. The specimen consists of a partial skull, a complete cervical and dorsal vertebral series with more than 40 vertebrae, ribs, both front flippers, and the left hind flipper. In 2023, Konishi ''et al.'' described ''Megapterygius wakayamaensis'' as a new genus and species of mosasaurine based on these fossil remains. The generic name, "''Megapterygius''", is derived from the Ancient Greek ''mégas'', meaning large, and ''pterygion'', meaning wing, referen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
