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Metriorhynchoids
Metriorhynchoidea is an extinct superfamily (biology), superfamily of thalattosuchian crocodyliforms from the Early Jurassic to the Early Cretaceous (Toarcian - Valanginian, possibly as late as early Aptian) of Europe, North America and South America. Metriorhynchids are fully aquatic crocodyliforms. Named by Leopold Fitzinger, Fitzinger, in 1843, it contains the basal taxa like ''Teleidosaurus'', ''Zoneait'' and ''Eoneustes'' and the family Metriorhynchidae. An unnamed taxon is known from Chile. Phylogeny Metriorhynchoidea is a stem-based taxon defined in the ''PhyloCode'' by Mark T. Young and colleagues in 2024 as "the largest clade within Thalattosuchia containing ''Metriorhynchus brevirostris'', but not ''Teleosaurus cadomensis'' and ''Macrospondylus bollensis''". The more derived clade Euthalattosuchia was named by Young and colleagues in 2024 to contain those thalattosuchians with both cranial and postcranial adaptations to a fully marine lifestye. It is defined in the ''P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zoneait Nargorum
''Zoneait'' (pronounced "zone-eight" and meaning "large tooth" in the Kiowa language) is an extinct genus of thalattosuchian crocodylomorph known from a single species, ''Zoneait nargorum'', from the Middle Jurassic Snowshoe Formation of Oregon. Discovery and naming The holotype was collected by Lupher and Packard.Éric Buffetaut, Buffetaut. (1979). Jour.Paleontology. 53,pt.1: 210, tf.2f,g. ''Z. nargorum'' was named in 2015 by paleontologist Eric Wilberg on the basis of several partial skulls, vertebrae, and forelimb bones that were found in an outcrop of the Weberg Member of the Snowshoe Formation near the town of Izee, Oregon, Izee. It is a member of Metriorhynchoidea, a clade of marine-adapted thalattosuchians that existed until the Early Cretaceous. Description and classification The skeleton of ''Zoneait'' possesses several adaptations for offshore marine life but retains features characteristic of its land-living ancestors, indicating that it is a transitional form betw ... [...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] |
Aptian
The Aptian is an age (geology), age in the geologic timescale or a stage (stratigraphy), stage in the stratigraphic column. It is a subdivision of the Early Cretaceous, Early or Lower Cretaceous epoch (geology), Epoch or series (stratigraphy), Series and encompasses the time from 121.4 ± 1.0 annum, Ma to 113.0 ± 1.0 Ma (million years ago), approximately. The Aptian succeeds the Barremian and precedes the Albian, all part of the Lower/Early Cretaceous. The Aptian partly overlaps the upper part of the Western Europe, Western European Urgonian Stage. The Selli Event, also known as OAE1a, was one of two oceanic anoxic events in the Cretaceous Period, which occurred around 120 annum, Ma and lasted approximately 1 to 1.3 million years, being marked by enhanced silicate weathering, as well as ocean acidification. The Aptian extinction was a minor extinction event hypothesized to have occurred around 116 to 117 Ma. Stratigraphic definitions The Aptian was named after the small city o ... [...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] |
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] |
Teleosaurus Cadomensis
''Teleosaurus'' (from , 'perfect' and , 'lizard') is an extinct genus of teleosaurid crocodyliform found in the Middle Jurassic Calcaire de Caen Formation of France. It was approximately in length. The holotype is MNHN AC 8746, a quarter of a skull and other associated postcranial remains, while other fragmentary specimens are known. The type species is ''T. cadomensis'', but a second species, ''T. geoffroyi'' may also exist. It was previously considered a wastebasket taxon, with many other remains assigned to the genus. History Teleosaur remains have been known to science since at least 1758, although at first scientists believed the remains belonged to extinct crocodiles and alligators, and remains that have at one point in time been attributed to ''Teleosaurus'' (and ''Steneosaurus'') have been known to science since at least 1800. The holotype was discovered during the early 19th century by Pierre Tesson before he traded it with Lamoroux. ''Teleosaurus'' was briefly no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metriorhynchus Brevirostris
''Metriorhynchus'' is an extinct genus of marine crocodyliform that lived in the oceans during the Late Jurassic. The type species, ''M. brevirostris'' was named in 1829 as a species of ''Steneosaurus'' before being named as a separate genus by the German palaeontologist Christian von Meyer in 1832. The name ''Metriorhynchus'' means "moderate snout", and is derived from the Greek ''Metrio''- ("moderate") and -''rhynchos'' ("snout"). Discovery and species Fossil specimens referrable to ''Metriorhynchus'' are known from Kimmeridgian (Late Jurassic) deposits of France. Valid species Only one valid species is recognized today, the type species ''M. geoffroyii'' (now called ''M. brevirostris''). ''"Metriorhynchus" hastifer'' and ''"M." palpebrosus'' are generically distinct from the ''Metriorhynchus'' type species, with ''hastifer'' being recovered as a geosaurine. Species in this genus were traditionally classed into two skull groups: longirostrine (long, narrow jaws) and brevirost ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clade
In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach to taxonomy adopted by most biological fields. The common ancestor may be an individual, a population, or a species (extinct or Extant taxon, extant). Clades are nested, one in another, as each branch in turn splits into smaller branches. These splits reflect evolutionary history as populations diverged and evolved independently. Clades are termed ''monophyletic'' (Greek: "one clan") groups. Over the last few decades, the cladistic approach has revolutionized biological classification and revealed surprising evolutionary relationships among organisms. Increasingly, taxonomists try to avoid naming Taxon, taxa that are not clades; that is, taxa that are not Monophyly, monophyletic. Some of the relationships between organisms that the molecul ... [...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] |
Stem-based Taxon
Phylogenetic nomenclature is a method of nomenclature for taxon, taxa in biology that uses phylogenetics, phylogenetic definitions for taxon names as explained below. This contrasts with Biological classification, the traditional method, by which taxon names are defined by a ''Type (biology), type'', which can be a specimen or a taxon of lower Taxonomic rank, rank, and a description in words. Phylogenetic nomenclature is regulated currently by the ''PhyloCode, International Code of Phylogenetic Nomenclature'' (''PhyloCode''). Definitions Phylogenetic nomenclature associates names with clades, groups consisting of an ancestor and all its descendants. Such groups are said to be Monophyly, monophyletic. There are slightly different methods of specifying the ancestor, which are discussed below. Once the ancestor is specified, the meaning of the name is fixed: the ancestor and all organisms which are its descendants are included in the taxon named. Listing all these organisms (i.e. prov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
