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Paratypothoracisini
Paratypothoracini is a clade of aetosaurs within the group Typothoracinae. It is a node-based taxon that includes '' Rioarribasuchus'' (='' Heliocanthus''), '' Paratypothorax'', '' Tecovasuchus'', and all descendants of their most recent common ancestor. The clade was first named in 2007 under the spelling Paraypothoracisini, after its namesake ''Paratypothorax''. However, this spelling was based on incorrect taxonomic nomenclature, and the clade's name was corrected to Paratypothoracinae in 2016. All synapomorphies that diagnose Paratypothoracini can be found in their osteoderm Osteoderms are bony deposits forming scales, plates, or other structures based in the dermis. Osteoderms are found in many groups of extant and extinct reptiles and amphibians, including lizards, crocodilians, frogs, temnospondyls (extinct amp ...s. The paramedian osteoderms are wide and lie flat, without any apparent flexure (a trait convergent with some desmatosuchin aetosaurs) The paramedians po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aetosaurs
Aetosaurs () are heavily armored reptiles belonging to the extinct order Aetosauria (; from Greek, (aetos, "eagle") and (, "lizard")). They were medium- to large-sized omnivorous or herbivorous pseudosuchians, part of the branch of archosaurs more closely related to crocodilians than to birds and other dinosaurs. All known aetosaurs are restricted to the Late Triassic, and in some strata from this time they are among the most abundant fossil vertebrates. They have small heads, upturned snouts, erect limbs, and a body ornamented with four rows of plate-like osteoderms (bony scutes). Aetosaur fossil remains are known from Europe, North and South America, parts of Africa, and India. Since their armoured plates are often preserved and are abundant in certain localities, aetosaurs serve as important Late Triassic tetrapod index fossils. Many aetosaurs had wide geographic ranges, but their stratigraphic ranges were relatively short. Therefore, the presence of particular aetosaurs can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aetosaur
Aetosaurs () are heavily armored reptiles belonging to the extinct order Aetosauria (; from Greek, (aetos, "eagle") and (, "lizard")). They were medium- to large-sized omnivorous or herbivorous pseudosuchians, part of the branch of archosaurs more closely related to crocodilians than to birds and other dinosaurs. All known aetosaurs are restricted to the Late Triassic, and in some strata from this time they are among the most abundant fossil vertebrates. They have small heads, upturned snouts, erect limbs, and a body ornamented with four rows of plate-like osteoderms (bony scutes). Aetosaur fossil remains are known from Europe, North and South America, parts of Africa, and India. Since their armoured plates are often preserved and are abundant in certain localities, aetosaurs serve as important Late Triassic tetrapod index fossils. Many aetosaurs had wide geographic ranges, but their stratigraphic ranges were relatively short. Therefore, the presence of particular aetosaurs can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paratypothorax
''Paratypothorax'' is an extinct genus of aetosaur, known from a single species, ''Paratypothorax andressorum''. It was a broadly distributed member of the group found in Germany, North America, and possibly parts of Gondwana. The best specimens come from Germany, though for more than a century they were mistakenly considered phytosaur armor. ''Paratypothorax'' was a large and wide-bodied typothoracine aetosaur, as well as the namesake of the tribe Paratypothoracisini. Discovery and distribution ''Paratypothorax'' was first known from specimens collected from the Heslach area near Stuttgart in Germany. These hail from the Stubensandstein (also known as the Löwenstein Formation), a mid- Norian age geological unit. Heslach has also produced many fossils of a smaller aetosaur, ''Aetosaurus''. The holotype specimen of ''Paratypothorax'', SMNS 5721, consists of a series of articulated osteoderms alongside a few hip and leg bones. Large osteoderms of ''Paratypothorax'' were lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paratypothorax Andressorum
''Paratypothorax'' is an extinct genus of aetosaur, known from a single species, ''Paratypothorax andressorum''. It was a broadly distributed member of the group found in Germany, North America, and possibly parts of Gondwana. The best specimens come from Germany, though for more than a century they were mistakenly considered phytosaur armor. ''Paratypothorax'' was a large and wide-bodied typothoracine aetosaur, as well as the namesake of the tribe Paratypothoracisini. Discovery and distribution ''Paratypothorax'' was first known from specimens collected from the Heslach area near Stuttgart in Germany. These hail from the Stubensandstein (also known as the Löwenstein Formation), a mid-Norian age geological unit. Heslach has also produced many fossils of a smaller aetosaur, ''Aetosaurus''. The holotype specimen of ''Paratypothorax'', SMNS 5721, consists of a series of articulated osteoderms alongside a few hip and leg bones. Large osteoderms of ''Paratypothorax'' were long mis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Desmatosuchini
Desmatosuchinae is a major subfamily of aetosaurs within the clade Desmatosuchia. It is a stem-based taxon defined as all aetosaurs more closely related to ''Desmatosuchus'' than to ''Stagonolepis,'' ''Aetosaurus'', or ''Paratypothorax''. The clade Desmatosuchinae has often been restricted to a few closely-related aetosaurs with spiny armor, such as ''Desmatosuchus'', ''Longosuchus'', and ''Lucasuchus''. It was later expanded to include a number of ''Stagonolepis''-like aetosaurs with less specialized armor. Under this more expansive usage, the strongly-supported clade encompassing "traditional" desmatosuchines (''sensu stricto'') was given a new name, Desmatosuchini. Synapomorphies that diagnose this clade can be found in the osteoderms. These include tongue-and-groove articulations for lateral plates present in dorsal presacral paramedian plates and large spikes on the lateral cervical, dorsal, and caudal plates. Timeline of generic descriptions ImageSize = width:1000px hei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osteoderm
Osteoderms are bony deposits forming scales, plates, or other structures based in the dermis. Osteoderms are found in many groups of extant and extinct reptiles and amphibians, including lizards, crocodilians, frogs, temnospondyls (extinct amphibians), various groups of dinosaurs (most notably ankylosaurs and stegosaurians), phytosaurs, aetosaurs, placodonts, and hupehsuchians (marine reptiles with possible ichthyosaur affinities). Osteoderms are uncommon in mammals, although they have occurred in many xenarthrans (armadillos and the extinct glyptodonts and mylodontid and scelidotheriid ground sloths). The heavy, bony osteoderms have evolved independently in many different lineages. The armadillo osteoderm is believed to develop in subcutaneous dermal tissues. These varied structures should be thought of as anatomical analogues, not homologues, and do not necessarily indicate monophyly. The structures are however derived from scutes, common to all classes of amniotes and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synapomorphies
In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to have evolved in their most recent common ancestor. ) In cladistics, synapomorphy implies homology. Examples of apomorphy are the presence of erect gait, fur, the evolution of three middle ear bones, and mammary glands in mammals but not in other vertebrate animals such as amphibians or reptiles, which have retained their ancestral traits of a sprawling gait and lack of fur. Thus, these derived traits are also synapomorphies of mammals in general as they are not shared by other vertebrate animals. Etymology The word —coined by German entomologist Willi Hennig—is derived from the Ancient Greek words (''sún''), meaning "with, together"; (''apó''), meaning "away from"; and (''morphḗ''), meaning "shape, form". Clade analysis T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heliocanthus
''Rioarribasuchus'' is a genus of aetosaur. Fossils have been found from the Chinle Formation in Arizona and New Mexico that date back to the upper Late Carnian stage of the Late Triassic. History ''"Desmatosuchus" chamaensis'' was named in 2003 and found from the Petrified Forest Member of the Chinle Formation in New Mexico. It was suggested to be more closely related to ''Paratypothorax'', and so Parker gave it the name ''Heliocanthus''. However, this new generic name was first proposed in an unpublished thesis, and thus did not meet ICZN regulations for the naming of a new taxon. Later published papers reasserted the genetic separation of ''"D". chamaensis'' from ''Desmatosuchus'', but the name ''Heliocanthus'' remained a ''nomen nudum'' until 2007, where it was thoroughly rediscribed in a paper published by the ''Journal of Systematic Palaeontology''. However, a paper previously published in late 2006 assigned ''"D". chamaensis'' to the new genus ''Rioarribasuchus''. As a re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Node-based Taxon
Phylogenetic nomenclature is a method of nomenclature for taxa in biology that uses phylogenetic definitions for taxon names as explained below. This contrasts with the traditional approach, in which taxon names are defined by a '' type'', which can be a specimen or a taxon of lower rank, and a description in words. Phylogenetic nomenclature is currently regulated by the '' International Code of Phylogenetic Nomenclature'' (''PhyloCode''). Definitions Phylogenetic nomenclature ties names to clades, groups consisting of an ancestor and all its descendants. These groups can equivalently be called monophyletic. There are slightly different ways 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 named taxon. Listing all these organisms (i.e. providing a full circumscription) requires the full phylogenetic tree to be known. In practice, ther ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Triassic
The Late Triassic is the third and final epoch (geology), epoch of the Triassic geologic time scale, Period in the geologic time scale, spanning the time between annum, Ma and Ma (million years ago). It is preceded by the Middle Triassic Epoch and followed by the Early Jurassic Epoch. The corresponding series (stratigraphy), series of rock beds is known as the Upper Triassic. The Late Triassic is divided into the Carnian, Norian and Rhaetian Geologic time scale, Ages. Many of the first dinosaurs evolved during the Late Triassic, including ''Plateosaurus'', ''Coelophysis'', and ''Eoraptor''. The Triassic–Jurassic extinction event began during this epoch and is one of the five major mass extinction events of the Earth. Etymology The Triassic was named in 1834 by Friedrich August von Namoh, Friedrich von Alberti, after a succession of three distinct rock layers (Greek meaning 'triad') that are widespread in southern Germany: the lower Buntsandstein (colourful sandstone'')'', t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Typothoracinae
Typothoracinae is a clade of aetosaurs within the subfamily Aetosaurinae. It was originally defined as a stem-based taxon including all aetosaurs closer to ''Typothorax'' than to ''Stagonolepis'' or ''Desmatosuchus''. This definition was later expanded to specifically exclude ''Aetosaurus''; as of 2016, Typothoracinae is defined as the least inclusive clade containing ''Typothorax'' and ''Paratypothorax'', but not ''Aetosaurus,'' ''Stagonolepis'', or ''Desmatosuchus''. The clade was first named in 2007 under the spelling Typothoracisinae, after its namesake ''Typothorax''. However, this spelling was based on incorrect taxonomic nomenclature, and the clade's name was corrected to Typothoracinae in 2016. Typothoracines can be distinguished by their wide bodies. The transverse processes of the dorsal (trunk) vertebrae are reinforced and elongated, more than twice the width of the centrum. Their neural spines, on the other hand, are short. The overlying carapace A carapace is a Do ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tecovasuchus
''Tecovasuchus'' is an extinct genus of aetosaur. It is known primarily from osteoderms found from the Tecovas Formation in Texas, which is Late Triassic in age, dating back to the lower Norian. Material is also known from several other localities of the Chinle Group in New Mexico and Arizona, such as older Carnian outcrops and younger Rhaetian outcrops. Specimens of ''Tecovasuchus'' have been collected from the Tecovas Formation, the Bluewater Creek Formation, and the Los Esteros Member of the Santa Rosa Formation. ''Tecovasuchus'' was first recognized as a new taxon in 1995, although it was not named until the description of the type species, ''T. chatterjeei'', in 2006. Before its description, specimens of ''Tecovasuchus'' were thought to belong to '' Paratypothorax'' or a ''Paratypothorax''-like aetosaur. Several features of the osteoderms distinguish ''Tecovasuchus'' from other aetosaur genera, including dorsal paramedian osteoderms with strongly thickened and beveled poste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
