|
2024 In Paleoichthyology
This list of fossil fish research presented in 2024 is a list of new fossil taxa of Agnatha, jawless vertebrates, placoderms, Chondrichthyes, cartilaginous fishes, Osteichthyes, bony fishes, and other fishes that were binomial nomenclature, described during the year, as well as other significant discoveries and events related to paleoichthyology that occurred in 2024. Jawless vertebrates Jawless vertebrate research * A study on the evolutionary history of hagfishes, as indicated by the fossil record and molecular data, is published by Brownstein & Near (2024), who consider the hagfish crown group to be a lineage with Early Permian origin and a long history in continental slope settings. * Brookfield (2024) interprets ''Jamoytius, Jamoytius kerwoodi'' as a probable detritivore or herbivore feeding on ''Dictyocaris'' (interpreted by the author as possible algal Thallus, thalli). * Evidence interpreted as indicating that oral plates of pteraspid heterostracans had a mechanical f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jamoytius
''Jamoytius kerwoodi'' is an extinct species of primitive, eel-like jawless fish known from the Patrick Burn Formation in Scotland, dating to the Llandovery epoch of the Early Silurian period. Long thought of as a "basal anaspid," ''J. kerwoodi'' is now recognized as the best-known member of the Hyperoartian order Jamoytiiformes. It had an elongated body, and is thought to have had, in comparison with relatives known from intact bodies like ''Euphanerops'', a dorsal fin and an anal fin near the rearmost third of its body. Earlier reconstructions depict the creature as having side-fins running the length of its body, starting from behind the branchial openings to the tip of its tail: new research demonstrates that such "fins" are actually deformations of the bodywall as the corpse was being squished post-burial. In life, ''J. kerwoodi'' resembled a lamprey with a very small mouth. Because the fossil had no teeth, teeth-like structures, nor suggestions of either in its mouth, it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Continental Slope
A continental margin is the outer edge of continental crust abutting oceanic crust under coastal waters. It is one of the three major zones of the ocean floor, the other two being deep-ocean basins and mid-ocean ridges. The continental margin consists of three different features: the continental rise, the continental slope, and the continental shelf. Continental margins constitute about 28% of the oceanic area. Subzones The continental shelf is the relatively shallow water area found in proximity to continents; it is the portion of the continental margin that transitions from the shore out towards to ocean. Continental shelves are believed to make up 7% of the sea floor. The width of continental shelves worldwide varies in the range of 0.03–1500 km. The continental shelf is generally flat, and ends at the shelf break, where there is a drastic increase in slope angle: The mean angle of continental shelves worldwide is 0° 07′, and typically steeper closer to the coa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crown Group
In phylogenetics, the crown group or crown assemblage is a collection of species composed of the living representatives of the collection, the most recent common ancestor of the collection, and all descendants of the most recent common ancestor. It is thus a way of defining a clade, a group consisting of a species and all its extant or extinct descendants. For example, Neornithes (birds) can be defined as a crown group, which includes the most recent common ancestor of all modern birds, and all of its extant or extinct descendants. The concept was developed by Willi Hennig, the formulator of phylogenetic systematics, as a way of classifying living organisms relative to their extinct relatives in his "Die Stammesgeschichte der Insekten", and the "crown" and "stem" group terminology was coined by R. P. S. Jefferies in 1979. Though formulated in the 1970s, the term was not commonly used until its reintroduction in 2000 by Graham Budd and Sören Jensen. Contents of the crow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hagfish
Hagfish, of the Class (biology), class Myxini (also known as Hyperotreti) and Order (biology), order Myxiniformes , are eel-shaped Agnatha, jawless fish (occasionally called slime eels). Hagfish are the only known living Animal, animals that have a skull but no vertebral column, although they do have rudimentary vertebrae. Hagfish are marine animal, marine predators and scavengers that can defend themselves against other larger predators by releasing copious amounts of slime coat, slime from mucous glands in their skin. Although their exact relationship to the only other extant taxon, living group of Agnatha, jawless fish, the lampreys, was long the subject of controversy, genetic evidence suggests that hagfish and lampreys are more closely related to each other than to jawed vertebrates, thus forming the superclass Cyclostomi. The oldest-known stem group hagfish are known from the Pennsylvanian (geology), Late Carboniferous, around Moscovian (Carboniferous), 310 million years ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weigeltaspididae
''Weigeltaspis'' is a genus of extinct heterostracan agnathan fish known from the Late Silurian and Early Devonian periods. Fossils are known primarily from Early Devonian-aged marine strata of Europe and Canada. Fragments and disarticulated plates of what may be of ''Weigeltaspis'' are known from Late Silurian-aged marine strata of Arctic Canada. Rare articulated fossils, plus the overall anatomy of its plates suggest the living animals were, at least superficially, similar to psammosteids, some authorities, such as Tarlo, place them within Psammosteida.Tarlo, Halstead. "LB t1965) Psammosteiformes tAgnatha)—A review with descriptions of new material from the Lower Devonian of Poland, II. Systematic Part." Palaeontologia Polonica 15: 168. Pages 20-21 Because the ornamentation on the plates and scales are very similar to the ornamentation seen on the plates and scales of '' Traquairaspis'' to the point of constant confusion, other authorities follow the lead of Obruchev, and p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tujiaaspis
''Tujiaaspis'' is an extinct genus of eugaleaspidiform that lived during the Telychian stage of the Llandovery epoch. Distribution ''Tujiaaspis vividus'' is known from the Huixingshao Formation of China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after .... References {{Taxonbar, from=Q123471046 Fossils of China Fossil taxa described in 2022 Galeaspida Prehistoric jawless fish genera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
