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Waaipoort Formation
The Waaipoort Formation is a Formation (geology), geologic formation in South Africa. It preserves fossils dating back to the Visean, in the Carboniferous Period (geology), period. Geology The Waaipoort formation consists of mudstones, siltstones, and fine sandstones and is around 35 meters thick. Fish-bearing localities are common and in most of these, the fish are present in calcitic or phosphatic nodules. At the Schiethoogte locality in the Eastern Cape, a 15 cm thickness (geology), thick black layer made up of siltstone and fine sandstone contains two horizons where Actinopterygii, actinopterygian fossils are closely packed. These are thought to represent mass mortality events. Paleoenvironment The Waaipoort formation has most commonly been interpreted as a marginal marine environment, possibly a lagoon or a River delta, delta. The fauna, composed mostly of palaeonisciformes, paleoniscoids, is a large divergence from the predominantly placoderm- and sarcopterygii, sarco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geological Formation
A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics (lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exposed in a geographical region (the stratigraphic column). It is the fundamental unit of lithostratigraphy, the study of strata or rock layers. A formation must be large enough that it can be mapped at the surface or traced in the subsurface. Formations are otherwise not defined by the thickness (geology), thickness of their rock strata, which can vary widely. They are usually, but not universally, tabular in form. They may consist of a single lithology (rock type), or of alternating beds of two or more lithologies, or even a heterogeneous mixture of lithologies, so long as this distinguishes them from adjacent bodies of rock. The concept of a geologic formation goes back to the beginnings of modern scientific geology. The term was used by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palaeonisciformes
The Palaeonisciformes (Palaeoniscida) are an extinct order of early ray-finned fishes (Actinopterygii). Palaeonisciformes '' sensu lato'' first appeared in the fossil record in the Late Silurian and last appeared in the Late Cretaceous. The name is derived from the Ancient Greek words παλαιός (''palaiós'', ancient) and ὀνίσκος (''oniskos'', 'cod-fish' or woodlouse), probably pertaining to the organization of the fishes' scales, similar to the exoskeletal plating of woodlice. In an early interpretation of the group, the Palaeonisciformes are divided in two suborders: Palaeoniscoidei (includes ''Palaeoniscum'' and fossil taxa with a broadly similar appearance) and Platysomoidei (includes '' Platysomus'' and other deep-bodied early actinopterygians). These groupings are considered paraphyletic today. In the cladistic sense, Palaeonisciformes ''sensu stricto'' should only refer to the Permian ''Palaeoniscum'', the name giving taxon, and all other taxa that fall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palaeonisciformes
The Palaeonisciformes (Palaeoniscida) are an extinct order of early ray-finned fishes (Actinopterygii). Palaeonisciformes '' sensu lato'' first appeared in the fossil record in the Late Silurian and last appeared in the Late Cretaceous. The name is derived from the Ancient Greek words παλαιός (''palaiós'', ancient) and ὀνίσκος (''oniskos'', 'cod-fish' or woodlouse), probably pertaining to the organization of the fishes' scales, similar to the exoskeletal plating of woodlice. In an early interpretation of the group, the Palaeonisciformes are divided in two suborders: Palaeoniscoidei (includes ''Palaeoniscum'' and fossil taxa with a broadly similar appearance) and Platysomoidei (includes '' Platysomus'' and other deep-bodied early actinopterygians). These groupings are considered paraphyletic today. In the cladistic sense, Palaeonisciformes ''sensu stricto'' should only refer to the Permian ''Palaeoniscum'', the name giving taxon, and all other taxa that fall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plesioselachus
''Plesioselachus'' is an extinct genus of Late Devonian (Famennian) cartilaginous fish with uncertain classification, which contains only one species, ''P. macracanthus'' from the Waterloo Farm lagerstätte in South Africa. Known from a single incomplete articulated skeleton and some isolated remains, it is characterized by having a long dorsal spine with length about one third of body length. Description ''Plesioselachus'' was originally classified as elasmobranch, however a redescription placed it under Chondrichthyes since it lacks sufficient data to consider what subgroup it belongs to. The holotype specimen, which has a preserved length of shows most of postcranial elements while lacking most of the head. It is originally considered that preserved lower jaw ( Meckel’s cartilage) and upper jaw ( palatoquadrate), however these materials are more likely to belong to ceratohyal and hyomandibula. The vertebral column is fully preserved, and extends for toward the caudal fin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chondrichthyes
Chondrichthyes (; ) is a class that contains the cartilaginous fishes that have skeletons primarily composed of cartilage. They can be contrasted with the Osteichthyes or ''bony fishes'', which have skeletons primarily composed of bone tissue. Chondrichthyes are jawed vertebrates with paired fins, paired nares, scales, and a heart with its chambers in series. Extant chondrichthyes range in size from the 10 cm (3.9 in) finless sleeper ray to the 10 m (32 ft) whale shark. The class is divided into two subclasses: Elasmobranchii (sharks, rays, skates, and sawfish) and Holocephali ( chimaeras, sometimes called ghost sharks, which are sometimes separated into their own class). Within the infraphylum Gnathostomata, cartilaginous fishes are distinct from all other jawed vertebrates. Anatomy Skeleton The skeleton is cartilaginous. The notochord is gradually replaced by a vertebral column during development, except in Holocephali, where the notochord stays intact. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gyracanthides Murrayi
''Gyracanthides'' is an extinct genus of acanthodian gnathostome, known from Devonian to Early Carboniferous. Description ''Gyracanthides'' is large acanthodian, ''G. murrayi'' reached the length up to . The pectoral fin spines are large compared to its body, for specimen that have estimated to be had pectoral fin spines around long. A recent study suggested that ''Gyracanthides'' is closely related to chondrichthyans (as currently delimited), and that acanthodians Acanthodii or acanthodians is an extinct class of gnathostomes (jawed fishes), typically considered a paraphyletic group. They are currently considered to represent a grade of various fish lineages leading up to the extant Chondrichthyes, which ... are paraphyletic. References Acanthodii genera Carboniferous acanthodians {{carboniferous-animal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Climatiiformes
The Climatiiformes is an order of extinct fish belonging to the class Acanthodii. Like most other "spiny sharks", the Climatiiformes had sharp spines. These animals were often fairly small in size and lived from the Late Silurian to the Early Carboniferous period. The type genus is ''Climatius''. The order used to be subdivided into the suborders Climatiida and Diplacanthida, but subsequently Diplacanthida has been elevated to a separate order, the Diplacanthiformes. The Diplacanthiformes take their name from ''Diplacanthus ''Diplacanthus'' is an extinct genus of Mid to Late Devonian fish in the class Acanthodii, known as spiny sharks. Classification The genus was named by Louis Agassiz in 1843. It was formerly regarded as belonging to the Climatiformes but r ...'', first described by Agassiz in 1843. Family Gyracanthidae is sometimes rejected from this order. References Acanthodii Prehistoric fish orders Paraphyletic groups {{Carboniferous-animal-st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bernard Price Institute For Palaeontological Research
The Evolutionary Studies Institute (ESI) is a paleontological, paleoanthropological and archeological research institute operated through the Faculty of Science of the University of the Witwatersrand, Johannesburg, South Africa. Previously known as the Bernard Price Institute for Palaeontological Research (BPI) it was renamed the Evolutionary Studies Institute in 2013 to better showcase the scope of its research. History The Evolutionary Studies Institute was first named the Bernard Price Institute after Bernard Price, an engineer and general manager of the Victoria Falls and Transvaal Power Company who provided steady research funding. The institute was set up in 1937 as an institute for geophysical research, but since has become known for its paleontological research. The institute's first director was Basil Schonland. When World War II began in 1939, the South African Defense Force ordered the BPI to contribute to the war effort. Schonland led the development of Sou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gyracanthides
''Gyracanthides'' is an extinct genus of acanthodian gnathostome, known from Devonian to Early Carboniferous. Description ''Gyracanthides'' is large acanthodian, ''G. murrayi'' reached the length up to . The pectoral fin spines are large compared to its body, for specimen that have estimated to be had pectoral fin spines around long. A recent study suggested that ''Gyracanthides'' is closely related to chondrichthyans (as currently delimited), and that acanthodians Acanthodii or acanthodians is an extinct class of gnathostomes (jawed fishes), typically considered a paraphyletic group. They are currently considered to represent a grade of various fish lineages leading up to the extant Chondrichthyes, which ... are paraphyletic. References Acanthodii genera Carboniferous acanthodians {{carboniferous-animal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acanthodian
Acanthodii or acanthodians is an extinct class of gnathostomes (jawed fishes), typically considered a paraphyletic group. They are currently considered to represent a grade of various fish lineages leading up to the extant Chondrichthyes, which includes living sharks, rays, and chimaeras. Acanthodians possess a mosaic of features shared with both osteichthyans (bony fish) and chondrichthyans (cartilaginous fish). In general body shape, they were similar to modern sharks, but their epidermis was covered with tiny rhomboid platelets like the scales of holosteians (gars, bowfins). A lower Silurian species, '' Fanjingshania renovata'', attributed to Climatiiformes is the oldest chondrichthyan with known anatomical features. The popular name "spiny sharks" is because they were superficially shark-shaped, with a streamlined body, paired fins, a strongly upturned tail, and stout, largely immovable bony spines supporting all the fins except the tail—hence, "spiny sharks". However, ac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
