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Thalattosuchians
Thalattosuchia is a clade of mostly marine crocodylomorphs from the Early Jurassic to the Early Cretaceous that had a cosmopolitan distribution. They are colloquially referred to as marine crocodiles or sea crocodiles, though they are not members of Crocodilia and records from Thailand and China suggest that some members lived in freshwater. The clade contains two major subgroupings, the Teleosauroidea and Metriorhynchoidea. Teleosauroids are not greatly specialised for oceanic life, with back osteoderms similar to other crocodyliformes. Within Metriorhynchoidea, the Metriorhynchidae displayed extreme adaptions for life in the open ocean, including the transformation of limbs into flippers, the development of a tail fluke, and smooth, scaleless skin, and probably gave Viviparity, live birth, seemingly uniquely among archosaurs. Taxonomy The term Thalattosuchia was coined by Fraas in 1901.Fraas E. 1901. Die Meerkrokodile (Thalattosuchia n. g.) eine neue Sauriergruppe der Juraform ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turnersuchus
''Turnersuchus'' is an extinct genus of thalattosuchian, a group of marine crocodylomorphs, from the Pliensbachian of the United Kingdom. It is the oldest diagnostic member of Thalattosuchia and was also found to be the group's most basal member, being situated outside the two major groups Metriorhynchoidea and Teleosauroidea. Subsequently, this genus is considered to be of great importance to understanding the relationship between thalattosuchians and other crocodylomorphs as well as their rapid diversification during the early Jurassic. ''Turnersuchus'' is a monotypic genus, meaning it includes only a single species, ''Turnersuchus hingleyae''. History and naming The fossils of ''Turnersuchus'' were discovered in 2017 within the Belemnite Marl Member of the British Charmouth Mudstone Formation in Dorset and the specimens were recorded under the West Dorset Fossil Collecting Code due to their rarity. The holotype, LYMPH 2021/45, is preserved in five large blocks with several ad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Jurassic
The Early Jurassic Epoch (geology), Epoch (in chronostratigraphy corresponding to the Lower Jurassic series (stratigraphy), Series) is the earliest of three epochs of the Jurassic Period. The Early Jurassic starts immediately after the Triassic–Jurassic extinction event, 201.3 Ma (million years ago), and ends at the start of the Middle Jurassic 174.7 ±0.8 Ma. Certain rocks of marine origin of this age in Europe are called "Lias Group, Lias" and that name was used for the period, as well, in 19th-century geology. In southern Germany rocks of this age are called Black Jurassic. Origin of the name Lias There are two possible origins for the name Lias: the first reason is it was taken by a geologist from an England, English quarryman's dialect pronunciation of the word "layers"; secondly, sloops from north Cornwall, Cornish ports such as Bude would sail across the Bristol Channel to the Vale of Glamorgan to load up with rock from coastal limestone quarries (lias and Carbonif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tail Fluke
A fin is a thin component or appendage attached to a larger body or structure. Fins typically function as foil (fluid mechanics), foils that produce lift (force), lift or thrust, or provide the ability to steer or stabilize motion while traveling in water, air, or other fluids. Fins are also used to Fin (extended surface), increase surface areas for heat transfer purposes, or simply as ornamentation. Fins first evolved on fish as a means of locomotion. Fish fins are used to generate thrust and control the subsequent motion. Fish and other aquatic animals, such as cetaceans, actively propel and steer themselves with pectoral fin, pectoral and Caudal fin, tail fins. As they swim, they use other fins, such as dorsal fin, dorsal and anal fins, to achieve stability and refine their maneuvering.Helfman G, Collette BB, Facey DE and Bowen BW (2009"Functional morphology of locomotion and feeding" Chapter 8, pp. 101–116. In:''The Diversity of Fishes: Biology'', John Wiley & Sons. . The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Notosuchus Terrestris
''Notosuchus'' (; 'southern crocodile') is an extinct genus of South American notosuchian crocodyliforms. It was terrestrial, living approximately 85 million years ago in the Santonian stage of the Late Cretaceous. Description ''Notosuchus'' was relatively small, reaching in length and a weight of . Remains have been found in the Bajo de la Carpa Formation in Patagonia, Argentina. First named in 1896, ''Notosuchus'' was the first known notosuchian. The type species is ''N. terrestris''. A second species, ''N. lepidus'', was named in 1957. A paper published in 2008 by Fiorelli and Calvo described new remains of the type species ''N. terrestris''. In it, the authors suggested that the skull would have supported a short trunk, or "hog's snout" as well as fleshy upper and lower lips. The anteriorly directed nares and the absence of a bony nasal septum (which presumably indicates cartilaginous tissue serving its place) provide evidence for a trunk-like snout, while striations on t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protosuchus Richardsoni
''Protosuchus'' (from , "first" and , "crocodile") is an extinct genus of carnivorous crocodyliform from the Early Jurassic. It is among the earliest animals that resemble crocodilians. ''Protosuchus'' was about in length and about in weight. As an early crocodilian relative, its skull featured more crocodilian characteristics than its earlier ancestors; it had short jaws that broadened out at the base of the skull, providing a large surface to which its jaw muscles could attach. This increased the maximum gape of the animal's mouth and the force with which the jaws could be closed. The dentition of the animal also resembled modern crocodiles, including the teeth in the lower jaw that fitted into notches on either side of the upper jaw when the mouth was closed. It also possessed a powerful tail which later developed into a propulsion mechanism through water in its descendants. The body was covered and reinforced by osteoderms in a double row along the back and covering the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thalattosuchus Superciliosus
''Thalattosuchus'' is an extinct genus of marine crocodyliform that lived in the oceans during the Middle to Late Jurassic. Though the genus ''Thalattosuchus'' itself was named in 2020, its fossils have historically been included under the well known name '' Metriorhynchus'' as the species ''M. superciliosus'', from which much of the research on the latter genus has been based upon. ''M. superciliosus'' was named as its own genus after a team of palaeontologists led by Mark Young in 2020 argued that the name ''Metriorhynchus'' could only be definitively applied to the type species, ''M. geoffroyii'', and named ''Thalattosuchus'' ("sea crocodile", and from its parent group Thalattosuchia). Not all researchers have accepted this split, and in 2022 another team led by Jonas le Mort have proposed ''Thalattosuchus'' be syonymised back into ''Metriorhynchus''. ''Thalattosuchus'' was a carnivore that spent much, if not all, its life out at sea. No ''Thalattosuchus'' eggs or nests have b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macrospondylus Bollensis
''Macrospondylus'' is an extinct genus of machimosaurid teleosauroid crocodyliform from the Early Jurassic (Toarcian) of Europe. Fossils are known from the Posidonia Shale of Germany, the Whitby Mudstone of the United Kingdom, and the "'' schistes bitumineux"'' of Luxembourg. Evolutionary relationships ''Macrospondylus'' has historically been synonymized with ''Steneosaurus''. A 2005 phylogenetic analysis of Thalattosuchia, however, did not support the monophyly of ''Steneosaurus'', as the genera '' Machimosaurus'' and ''Teleosaurus'' both fell within ''Steneosaurus''. Reinforcing the paraphyly of ''Steneosaurus'', Young et al. (2012), Ősi et al. (2018), and Wilberg et al. (2019) recovered ''Steneosaurus bollensis'' and other ''Steneosaurus'' species in disparate positions within Teleosauridae. In 2016, its length was estimated at , making it the largest known Early Jurassic crocodylomorph. In 2020, the genus was formally revived. Palaeobiology ''M. bollensis'' exhibited ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PhyloCode
The ''International Code of Phylogenetic Nomenclature'', known as the ''PhyloCode'' for short, is a formal set of rules governing phylogenetic nomenclature. Its current version is specifically designed to regulate the naming of clades, leaving the governance of species names up to the rank-based nomenclature codes ('' ICN'', '' ICNCP'', '' ICNP'', '' ICZN'', '' ICVCN''). The ''PhyloCode'' is associated with the International Society for Phylogenetic Nomenclature (ISPN). The companion volume, ''Phylonyms'', establishes 300 taxon names under ''PhyloCode'', serving as examples for those unfamiliar with the code. RegNum is an associated online database for registered clade names. The ''PhyloCode'' regulates phylogenetic nomenclature by providing rules for deciding which associations of names and definitions are considered established, which of those will be considered homonyms or synonyms, and which one of a set of synonyms or homonyms will be considered accepted (generally the one ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Convergent Evolution
Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last common ancestor of those groups. The cladistic term for the same phenomenon is Cladogram#Homoplasies, homoplasy. The recurrent evolution of flight is a classic example, as flying pterygota, insects, birds, pterosaurs, and bats have independently evolved the useful capacity of flight. Functionally similar features that have arisen through convergent evolution are ''analogous'', whereas ''homology (biology), homologous'' structures or traits have a common origin but can have dissimilar functions. Bird, bat, and pterosaur wings are analogous structures, but their forelimbs are homologous, sharing an ancestral state despite serving different functions. The opposite of convergence is divergent evolution, where related species evolve different trai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neosuchia
Neosuchia is a clade within Mesoeucrocodylia that includes all modern extant crocodilians and their closest fossil relatives. It is defined as the most inclusive clade containing all Crocodylomorpha, crocodylomorphs more closely related to ''Crocodylus niloticus'' (the Nile Crocodile) than to ''Notosuchus terrestris''. Members of Neosuchia generally share a crocodilian-like bodyform adapted to freshwater aquatic life, as opposed to the terrestrial habits of more basal crocodylomorph groups. The earliest neosuchian is suggested to be the Early Jurassic ''Calsoyasuchus'', which lived during the Sinemurian and Pliensbachian stages in North America. It is often identified as a member of Goniopholididae, though this is disputed, and the taxon may lie outside Neosuchia, which places the earliest records of the group in the Middle Jurassic. Characteristics Members of Neosuchia have a wide diversity of skull shapes. Several groups convergently evolved elongate gharial-like skulls, which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraphyletic
Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In contrast, a monophyletic grouping (a clade) includes a common ancestor and ''all'' of its descendants. The terms are commonly used in phylogenetics (a subfield of biology) and in the tree model of historical linguistics. Paraphyletic groups are identified by a combination of synapomorphies and symplesiomorphies. If many subgroups are missing from the named group, it is said to be polyparaphyletic. The term received currency during the debates of the 1960s and 1970s accompanying the rise of cladistics, having been coined by zoologist Willi Hennig to apply to well-known taxa like Reptilia (reptiles), which is paraphyletic with respect to birds. Reptilia contains the last common ancestor of reptiles and all descendants of that ancestor exc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesosuchia
"Mesosuchia" is an obsolete name for a group of terrestrial, semi-aquatic, or fully aquatic crocodylomorph reptiles. Characteristics The marine crocodile '' Metriorhynchus'' had paddle-like forelimbs, '' Dakosaurus andiniensis'' had a skull that was adapted to eat large sea reptiles, and '' Shamosuchus'' was adapted for eating molluscs and gastropods. ''Shamosuchus'' also looked like modern crocodiles and was very closely related to their direct ancestor. History The "Mesosuchia" were formerly placed at Suborder rank as within Crocodylia. The "first" crocodiles were placed within their own suborder, Protosuchia; whilst extant species where placed within Suborder Eusuchia (meaning 'true crocodiles'). Mesosuchia were the crocodylians "in between".But it is no longer regarded as genuine because it belongs to a paraphyletic group. It is replaced by its phylogenetic equivalent Mesoeucrocodylia, which contains the taxa herein, the Crocodylia, and some allied forms more recently discover ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
