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Dinichthyloidea
The Dinichthyloidea is an extinct superfamily of placoderms, armored fish most diverse during the Devonian. However, the term is no longer in use, as modern cladistical methods have produced alternative phylogenetic trees of Brachythoraci with new subdivisions. Systematics * Basal genus '' Erromenosteus'' * Family Dinichthyidae * Family Trematosteidae * Family Rhachiosteidae * Family Pachyosteidae * Family Titanichthyidae * Family Bungartiidae * Family Selenosteidae Selenosteidae is an extinct family of small to large-sized arthrodire placoderms from the Late Devonian. With the exception of the Chinese ''Phymosteus'', selenosteids lived in shallow seas in what is now Eastern North America (the Cleveland Sha ... * Family Mylostomatidae References Arthrodires Vertebrate superfamilies {{Placoderm-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erromenosteus
''Erromenosteus'' is a genus of extinct, medium-sized brachythoracid arthrodire placoderm from the Late Frasnian of the Kellwasserkalk facies of Late Devonian Bad Wildungen and Bicken, Germany. The various species had bullet-shaped heads, and curved, crushing jaws. Species List As was mentioned, all known species are from the German Kellwasserkalk facies. Denison (1978) says that the various species need to be revised, as many of the species were originally described as specimens of other species. Obruchev (1932) and Miles (1969) placed ''Leiosteus'' (=''Erromenosteus'') within Pachyosteidae (before Pachyosteidae was merged into Selenosteidae). Now, though, ''Erromenosteus'' is considered a basal member of Dinichthyloidea. ''Erromenosteus'' * ''Erromenosteus lucifer'', the type species. The holotype is a long skull. ''Leiosteus'' These species were originally classified within ''Leiosteus'' before the genus was synonymized with ''Erromenosteus''. * ''Erromenosteus br ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Selenosteus
''Selenosteus brevis'' is an extinct large selenosteid arthrodire placoderm known from the Famennian Cleveland Shale of Ohio. Scrappy remains from the Frasnian Rhinestreet Shales of Erie County, New York, were attributed by Hussakof and Bryant to this genus in 1919, but, this identification is doubtful. A second species, ''S. kepleri'', was described in 1901, but, not enough differences can be seen between its specimens, and those of the type species to warrant new species status. According to its generally scrappy fossils, ''S. brevis'' had a wide skull with tremendous orbits. And as typical for selenosteids, ''S. brevis'' had weak gnathal plates. The median dorsal plate is crescent-shaped, and has a keel. The average length of the skull is about 16 centimetres from the tip of the rostrum to the posterior border of the nuchal The nape is the back of the neck. In technical anatomical/medical terminology, the nape is also called the nucha (from the Medieval Latin rendering ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silurian
The Silurian ( ) is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the shortest period of the Paleozoic Era. As with other geologic periods, the rock beds that define the period's start and end are well identified, but the exact dates are uncertain by a few million years. The base of the Silurian is set at a series of major Ordovician–Silurian extinction events when up to 60% of marine genera were wiped out. One important event in this period was the initial establishment of terrestrial life in what is known as the Silurian-Devonian Terrestrial Revolution: vascular plants emerged from more primitive land plants, dikaryan fungi started expanding and diversifying along with glomeromycotan fungi, and three groups of arthropods (myriapods, arachnids and hexapods) became fully terrestrialized. A significant evolutionary milestone during ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Selenosteidae
Selenosteidae is an extinct family of small to large-sized arthrodire placoderms from the Late Devonian. With the exception of the Chinese ''Phymosteus'', selenosteids lived in shallow seas in what is now Eastern North America (the Cleveland Shale), Eastern Europe (Holy Cross Mountains, Poland, and the Kellwasserkalk fauna of Bad Wildungen), and Northeastern Africa (the Anti-Atlas Mountains, Morocco). Selenosteids have, in cross section, a rounded body, a blunt snout, and tremendous orbits. The lower jaws were slender, the inferognathals usually either being finely serrated, or adapted for crushing, though, in '' Draconichthys'', the inferognathals had long prongs for seizing prey. The rostrum is very small. Taxonomy Selenosteidae is a member of the clade Aspinothoracidi, which belongs to the clade Pachyosteomorphi, one of the two major clades within Eubrachythoraci. ''Gorgonichthys'' is closely related to the family Selenosteidae, and could possibly be included in the family. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Titanichthyidae
''Titanichthys'' is an extinct genus of giant, aberrant marine placoderm from shallow seas of the Late Devonian of Morocco, Eastern North America, and possibly Europe. Many of the species approached '' Dunkleosteus'' in size and build. Unlike its relative, however, the various species of ''Titanichys'' had small, ineffective-looking mouth-plates that lacked a sharp cutting edge. It is assumed that ''Titanichthys'' was a filter feeder that used its capacious mouth to swallow or inhale schools of small, anchovy-like fish, or possibly krill-like zooplankton, and that the mouth-plates retained the prey while allowing the water to escape as it closed its mouth. A study has since confirmed this assumption as its jaws are functionally closer to that of filter feeders like baleen whales and basking sharks, and it appears to have developed from benthic durophagists that became pelagic suspension feeders. This would make it the first (known) large-sized vertebrate filter feeder. ''Titan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhachiosteidae
''Rhachiosteus'' is an extinct monospecific genus of arthrodire placoderm from the Middle to Late Devonian of Germany. It is known only from a single specimen, which may be a larval or juvenile form, as the skull of said specimen is only 19 millimetres long. Phylogeny ''Rhachiosteus'' is a basal member of the clade Pachyosteomorphi, the sister taxon to Coccosteomorphi, which together are the two main sub-clades of Eubrachythoraci. The cladogram below shows the phylogeny A phylogenetic tree (also phylogeny or evolutionary tree Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA.) is a branching diagram or a tree showing the evolutionary relationships among various biological spec ... of ''Rhachiosteus'': References Arthrodires Placoderms of Europe Arthrodire genera {{Placoderm-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dinichthyidae
''Dinichthys'' (from el, δεινός , 'terrible' and el, ἰχθύς 'fish') is an extinct monospecific genus of giant, marine arthrodire placoderm from the Late Devonian (Famennian stage), comparable in size, shape, and ecological role to the better-known ''Dunkleosteus''. Fossils were recovered from the Ohio Shale Formation along the Olentangy River in Delaware County, Ohio. Classification History ''Dinichthys'' was originally described in 1868 by John Newberry on the basis of an incomplete skull roof and mandibles (holotype AMNH 81). Subsequently, many unrelated large arthrodires were originally classified together within this genus, including species now assigned to ''Dunkleosteus'', '' Eastmanosteus'', and ''Titanichthys''. Notably, the type species of ''Dunkleosteus'' was originally described as ''Dinichthys terrelli'' by Newberry in 1873, and was later separated into ''Dunkleosteus'' by Jean-Pierre Lehman in 1956. ''Dunkleosteus'' was still thought to be close ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Family (biology)
Family ( la, familia, plural ') is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between order and genus. A family may be divided into subfamilies, which are intermediate ranks between the ranks of family and genus. The official family names are Latin in origin; however, popular names are often used: for example, walnut trees and hickory trees belong to the family Juglandaceae, but that family is commonly referred to as the "walnut family". What belongs to a family—or if a described family should be recognized at all—are proposed and determined by practicing taxonomists. There are no hard rules for describing or recognizing a family, but in plants, they can be characterized on the basis of both vegetative and reproductive features of plant species. Taxonomists often take different positions about descriptions, and there may be no broad consensus across the scientific community for some time. The publishing of new data and opini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
