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Diademodus
''Diademodus'' is an extinct genus of phoebodontid elasmobranch that lived during the Late Devonian Period. The genus was first described by paleontologist John E. Harris based on a body fossil from the Cleveland Shale formation of Ohio. Teeth belonging to this genus have also been uncovered in Utah, Nevada, Western Australia, and Russia. Description According to Harris, ''Diademodus'' was a long, slender cartilaginous fish with a body length of up to . He also stated that ''Diademodus body may have been slightly wider than it was tall, making it comparable to the modern catshark genus ''Scyliorhinus.'' Like most cartilaginous fish, its body was covered in tooth-like dermal denticles. These denticles were shorter near the animal's head and larger in rows along its lateral line. The tail lacked an exaggerated keel like that seen in the contemporaneous genus ''Cladoselache''. Fins ''Diademodus'' possesses unusual fin morphology compared to other known chondrichthyans. Its pec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cleveland Shale
The Cleveland Shale, also referred to as the Cleveland Member of the Ohio Shale, is a Late Devonian (Famennian) shale Member (geology), geologic member in the eastern United States. Identification and name The Cleveland Shale was identified in 1870 and named for the city of Cleveland, Ohio. John Strong Newberry, director of the Ohio State Geological Survey, first identified the member in 1870. He called it the "Cleveland Shale" and designated its Type locality (geology), type locality at Doan Brook near Cleveland. Details of the type locality and of stratigraphic nomenclature for this unit as used by the U.S. Geological Survey are available on-line at the National Geologic Map Database. Description The primary minerals in the Cleveland Shale are chlorite, illite, pyrite, and quartz. Underground, the Cleveland Shale is black, dull grayish-black, bluish-black, or brownish-black in color. In exposed outcrops, it weathers to red, reddish-brown, or medium brown. Highly weathered r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phoebodontidae
Phoebodontiformes is an extinct group of elasmobranchs (''sensu lato''), known from the Devonian and Carboniferous periods. It includes the genera '' Phoebodus'', ''Diademodus'' and ''Thrinacodus''. ''Phoebodus'' and ''Thrinacodus'' have slender, elongate bodies. Their teeth are tricuspate (bearing three cusps). Some studies have recovered the group as paraphyletic. '' Jalodus'' and other members of the family Jalodontidae, which range from the Devonian to the Triassic The Triassic ( ; sometimes symbolized 🝈) is a geologic period and system which spans 50.5 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.4 Mya. The Triassic is t ..., were formerly included in this order, but have subsequently been assigned to their own order, the Jalodontiformes. References Prehistoric cartilaginous fish orders Devonian cartilaginous fish Carboniferous cartilaginous fish {{paleo-cartilagi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Devonian
The Devonian ( ) is a geologic period and system of the Paleozoic era during the Phanerozoic eon, spanning 60.3 million years from the end of the preceding Silurian period at million years ago ( Ma), to the beginning of the succeeding Carboniferous period at Ma. It is the fourth period of both the Paleozoic and the Phanerozoic. It is named after Devon, South West England, where rocks from this period were first studied. The first significant evolutionary radiation of life on land occurred during the Devonian, as free- sporing land plants (pteridophytes) began to spread across dry land, forming extensive coal forests which covered the continents. By the middle of the Devonian, several groups of vascular plants had evolved leaves and true roots, and by the end of the period the first seed-bearing plants ( pteridospermatophytes) appeared. This rapid evolution and colonization process, which had begun during the Silurian, is known as the Silurian-Devonian Terrestrial Rev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scyliorhinus
''Scyliorhinus'' is a genus of catsharks in the family Scyliorhinidae. This genus is known in the fossil records from the Cretaceous period, late Albian age to the Pliocene epoch.Carrier, J. C.; Musick, J. A. & Heithaus, M. R. (2004)''Biology of Sharks and Their Relatives'' Species There are currently 16 recognized species in this genus: * ''Scyliorhinus boa'' Goode & T. H. Bean, 1896 (boa catshark) * '' Scyliorhinus cabofriensis'' K. D. A. Soares, U. L. Gomes & M. R. de Carvalho, 2016Soares, K.D.A., Gomes, U.L. & De Carvalho, M.R. (2016): Taxonomic review of catsharks of the ''Scyliorhinus haeckelii'' group, with the description of a new species (Chondrichthyes: Carcharhiniformes: Scyliorhinidae). ''Zootaxa, 4066 (5): 501-534.'' * ''Scyliorhinus canicula'' (Linnaeus, 1758) (small-spotted catshark) * '' Scyliorhinus capensis'' ( J. P. Müller & Henle, 1838) (yellowspotted catshark) * ''Scyliorhinus cervigoni'' Maurin & M. Bonnet, 1970 (West African catshark) * ''Scyliorhin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterocercal
Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported only by muscles. Fish fins are distinctive anatomical features with varying structures among different clades: in ray-finned fish (Actinopterygii), fins are mainly composed of bony spines or rays covered by a thin stretch of scaleless skin; in lobe-finned fish (Sarcopterygii) such as coelacanths and lungfish, fins are short rays based around a muscular central bud supported by jointed bones; in cartilaginous fish (Chondrichthyes) and jawless fish (Agnatha), fins are fleshy " flippers" supported by a cartilaginous skeleton. Fins at different locations of the fish body serve different purposes, and are divided into two groups: the midsagittal ''unpaired fins'' and the more laterally located ''paired fins''. Unpaired fins are predominant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pelvic Fin
Pelvic fins or ventral fins are paired fins located on the ventral (belly) surface of fish, and are the lower of the only two sets of paired fins (the other being the laterally positioned pectoral fins). The pelvic fins are homologous to the hindlimbs of tetrapods, which evolved from lobe-finned fish during the Middle Devonian. Structure and function Structure In actinopterygians, the pelvic fin consists of two endochondrally-derived bony girdles attached to bony radials. Dermal fin rays ( lepidotrichia) are positioned distally from the radials. There are three pairs of muscles each on the dorsal and ventral side of the pelvic fin girdle that abduct and adduct the fin from the body. Pelvic fin structures can be extremely specialized in actinopterygians. Gobiids and lumpsuckers modify their pelvic fins into a sucker disk that allow them to adhere to the substrate or climb structures, such as waterfalls. In priapiumfish, males have modified their pelvic structures into ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dorsal Fin
A dorsal fin is a fin on the back of most marine and freshwater vertebrates. Dorsal fins have evolved independently several times through convergent evolution adapting to marine environments, so the fins are not all homologous. They are found in most fish, in mammals such as whales, and in extinct ancient marine reptiles such as ichthyosaurs. Most have only one dorsal fin, but some have two or three. Wildlife biologists often use the distinctive nicks and wear patterns which develop on the dorsal fins of whales to identify individuals in the field. The bones or cartilages that support the dorsal fin in fish are called pterygiophores. Functions The main purpose of the dorsal fin is usually to stabilize the animal against rolling and to assist in sudden turns. Some species have further adapted their dorsal fins to other uses. The sunfish uses the dorsal fin (and the anal fin Fins are moving appendages protruding from the body of fish that interact with water to ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pectoral Fins
Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported only by muscles. Fish fins are distinctive anatomical features with varying structures among different clades: in ray-finned fish (Actinopterygii), fins are mainly composed of bony spines or rays covered by a thin stretch of scaleless skin; in lobe-finned fish (Sarcopterygii) such as coelacanths and lungfish, fins are short rays based around a muscular central bud supported by jointed bones; in cartilaginous fish (Chondrichthyes) and jawless fish (Agnatha), fins are fleshy " flippers" supported by a cartilaginous skeleton. Fins at different locations of the fish body serve different purposes, and are divided into two groups: the midsagittal ''unpaired fins'' and the more laterally located ''paired fins''. Unpaired fins are predominantly a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Morphology (biology)
Morphology (from Ancient Greek μορφή (morphḗ) "form", and λόγος (lógos) "word, study, research") is the study of the form and structure of organisms and their specific structural features. This includes aspects of the outward appearance (shape, structure, color, pattern, size), as well as the form and structure of internal parts like bones and organs, i.e., anatomy. This is in contrast to physiology, which deals primarily with function. Morphology is a branch of life science dealing with the study of the overall structure of an organism or taxon and its component parts. History The etymology of the word "morphology" is from the Ancient Greek (), meaning "form", and (), meaning "word, study, research". While the concept of form in biology, opposed to function, dates back to Aristotle (see Aristotle's biology), the field of morphology was developed by Johann Wolfgang von Goethe (1790) and independently by the German anatomist and physiologist Karl Fried ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish Fin
Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported only by muscles. Fish fins are distinctive anatomical features with varying structures among different clades: in ray-finned fish (Actinopterygii), fins are mainly composed of bony spines or rays covered by a thin stretch of scaleless skin; in lobe-finned fish ( Sarcopterygii) such as coelacanths and lungfish, fins are short rays based around a muscular central bud supported by jointed bones; in cartilaginous fish ( Chondrichthyes) and jawless fish ( Agnatha), fins are fleshy " flippers" supported by a cartilaginous skeleton. Fins at different locations of the fish body serve different purposes, and are divided into two groups: the midsagittal ''unpaired fins'' and the more laterally located ''paired fins''. Unpaired fins are p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cladoselache
''Cladoselache'' ("branch shark") is an Extinction, extinct genus of shark-like chondrichthyan (cartilaginous fish) from the Late Devonian (Famennian) of North America. It was similar in body shape to modern Lamnidae, lamnid sharks (such as Isurus, mako sharks and the great white shark), but was not closely related to lamnids or to any other modern (selachian) shark. As an early chondrichthyan, it had yet to evolve traits of modern sharks such as accelerated tooth replacement, a loose jaw suspension, enameloid teeth, and possibly Clasper, claspers. Some 20th century studies considered ''Cladoselache'' to be a Basal (phylogenetics), basal (early-diverging) member of Elasmobranchii, the fork of cartilaginous fish which leads to modern sharks and rays. More recent studies have identified distinctive traits of the chondrocranium (cartilaginous braincase), dorsal fin spines, and pectoral fin bases. These newly identified features support a close relationship to Symmoriiformes, symmorii ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
