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Carchariidae
Carchariidae is a family of lamniform sharks containing a single extant genus, '' Carcharias'', The family was recognized as distinct as early as 1838, but afterwards, it was grouped with the superficially very similar genus ''Odontaspis'' into the family Odontaspididae. However, phylogenetic studies since the 21st century have discovered that this placement is paraphyletic, with ''Carcharias'' being the second most basal extant lamniform after the goblin sharks, while ''Odontaspis'' diverged from the rest of the lamniforms only afterwards, and is thus more closely related to derived lamniforms. For this reason, the family Carchariidae was revived in 2019, and is presently accepted by ''Eschmeyer's Catalog of Fishes'' and the Shark-References database. Aside from the stratigraphically widespread genus ''Carcharias'', known from the Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geolo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lamniform
The Lamniformes (, from Greek ''lamna'' "fish of prey") are an order of sharks commonly known as mackerel sharks (which may also refer specifically to the family Lamnidae). It includes some of the most familiar species of sharks, such as the great white as well as less familiar ones, such as the goblin shark and megamouth shark. Members of the order are distinguished by possessing two dorsal fins, an anal fin, five gill slits, eyes without nictitating membranes, and a mouth extending behind the eyes. Species in two families of Lamniformes – Lamnidae and Alopiidae – are distinguished for maintaining a higher body temperature than the surrounding waters. Members of the group include macropredators, generally of medium-large size, including the largest macropredatory shark ever, the extinct '' Otodus megalodon,'' as well as large planktivores. Although some authors have argued that the Late Jurassic '' Palaeocarcharias'' should be considered the oldest known lamniform, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carcharias
''Carcharias'', also known as sand tiger sharks, is a genus of mackerel sharks belonging to the family Carchariidae, of which it is the only extant member. Once bearing many prehistoric species, all have gone extinct with the exception of the critically endangered sand tiger shark Description ''Carcharias'' are long on average. The maximum weight of the shark is . Differentiating species of sharks is usually done by locating and measuring their fins. The tail is one third of the entire body size. The second dorsal fin and the anal fin of ''Carcharias'' are very large and about equal in size. The pectoral fins are triangular and only slightly larger than the dorsal fins. The teeth are very long and narrow with sharp points, and smooth with no ridges. Diet ''Carcharias'' species are generalist predators that hunt bony fish, small sharks, rays, squids, crabs and lobsters. Habitat Sand tiger sharks are found in the Pacific, Atlantic and Indian oceans. They live in water depths ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the Latin word for the white limestone known as chalk. The chalk of northern France and the white cliffs of south-eastern England date from the Cretaceous Period. Climate During the Late Cretaceous, the climate was warmer than present, although throughout the period a cooling trend is evident. The tropics became restricted to equatorial regions and northern latitudes experienced markedly more seasonal climatic conditions. Geography Due to plate tectonics, the Americas were gradually moving westward, causing the Atlantic Ocean to expand. The Western Interior Seaway divided North America into eastern and western halves; Appalachia and Laramidia. India maintained a northward course towards Asia. In the Southern Hemisphere, Aus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sand Tiger Shark
The sand tiger shark (''Carcharias taurus''), grey/gray nurse shark (in Australia), spotted ragged-tooth shark (in South Africa), or blue-nurse sand tiger, is a species of shark that inhabits subtropical and temperate waters worldwide. It inhabits the continental shelf, from sandy shorelines (hence the name sand tiger shark) and submerged reefs to a depth of around . They dwell in the waters of Japan, Australia, South Africa, and the east coasts of North and South America. The sand tiger shark also inhabited the Mediterranean, however it was last seen there in 2003 and is presumed extirpated. Despite its common names, it is not closely related to either the tiger shark (''Galeocerdo cuvier'') or the nurse shark (''Ginglymostoma cirratum''). Despite its fearsome appearance and strong swimming ability, it is a relatively placid and slow-moving shark with no confirmed human fatalities. This species has a sharp, pointy head, and a bulky body. The sand tiger's length can reach but is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Johannes Peter Müller
Johannes Peter Müller (14 July 1801 – 28 April 1858) was a German physiologist, comparative anatomist, ichthyologist, and herpetologist, known not only for his discoveries but also for his ability to synthesize knowledge. The paramesonephric duct (Müllerian duct) was named in his honor. Life Early years and education Müller was born in Coblenz. He was the son of a poor shoemaker, and was about to be apprenticed to a saddler when his talents attracted the attention of his teacher, and he prepared himself to become a Roman Catholic Priest. During his college course in Koblenz, he devoted himself to the classics and made his own translations of Aristotle. At first, his intention was to become a priest. When he was eighteen, his love for natural science became dominant, and he turned to medicine, entering the University of Bonn in 1819. There he received his M.D. in 1822. He then studied at the University of Berlin. There, under the influence of G. W. F. Hegel and Kar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Friedrich Gustav Jakob Henle
Friedrich Gustav Jakob Henle (; 9 July 1809 – 13 May 1885) was a German physician, pathologist, and anatomist. He is credited with the discovery of the loop of Henle in the kidney. His essay, "On Miasma and Contagia," was an early argument for the germ theory of disease. He was an important figure in the development of modern medicine. Biography Henle was born in Fürth, Bavaria, to Simon and Rachel Diesbach Henle (Hähnlein). He was Jewish. After studying medicine at Heidelberg and at Bonn, where he took his doctor's degree in 1832, he became prosector in anatomy to Johannes Müller at Berlin. During the six years he spent in that position he published a large amount of work, including three anatomical monographs on new species of animals and papers on the structure of the lymphatic system, the distribution of epithelium in the human body, the structure and development of the hair, and the formation of mucus and pus. He also developed a friendship with another ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Family (biology)
Family (, : ) 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". The delineation of what constitutes a family—or whether a described family should be acknowledged—is established and decided upon by active taxonomists. There are not strict regulations for outlining or acknowledging a family, yet in the realm of plants, these classifications often rely on both the vegetative and reproductive characteristics of plant species. Taxonomists frequently hold varying perspectives on these descriptions, leading to a lack of widespread consensus within the scientific community ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shark
Sharks are a group of elasmobranch cartilaginous fish characterized by a ribless endoskeleton, dermal denticles, five to seven gill slits on each side, and pectoral fins that are not fused to the head. Modern sharks are classified within the Division (taxonomy), division Selachii and are the sister group to the Batoidea, Batomorphi (Batoidea, rays and skate (fish), skates). Some sources extend the term "shark" as an informal category including Extinction, extinct members of Chondrichthyes (cartilaginous fish) with a shark-like morphology, such as hybodonts. Shark-like chondrichthyans such as ''Cladoselache'' and ''Doliodus'' first appeared in the Devonian Period (419–359 million years), though some fossilized chondrichthyan-like scales are as old as the Ordovician, Late Ordovician (458–444 million years ago). The earliest confirmed modern sharks (Selachii) are known from the Early Jurassic around , with the oldest known member being ''Agaleus'', though records of true shar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Odontaspis
''Odontaspis'' (from 'tooth') and 'shield') is a genus of sand shark with two extant species. Description Bigeye sand tigers can reach a length of about and smalltooth sand tigers of about 4.1 m. They are large-bodied sharks with long, conical snouts, broad-based dorsal and anal fins, and an asymmetrical caudal fin with a strong lower lobe. Their teeth are large, with prominent narrow cusps. They are distinguished from the similar genus '' Carcharias'' by the absence of crushing posterior teeth.Bourdon, J''Odontaspis'' Agassiz 1838 ''Elasmo.com''. Retrieved on December 24, 2008. These bottom dwelling, deepwater sharks can be found in temperate and tropical waters of all the oceans. Extant species * '' Odontaspis ferox'' ( A. Risso, 1810) (smalltooth sand tiger) * '' Odontaspis noronhai'' ( Maul, 1955) (bigeye sand tiger) Extinct species Extinct species within this genus include: * ''Odontaspis aculeatus'' Capetta & Case, 1975 * ''Odontaspis speyeri'' (Dartevel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraphyly
Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In contrast, a monophyletic grouping (a clade) includes a common ancestor and ''all'' of its descendants. The terms are commonly used in phylogenetics (a subfield of biology) and in the tree model of historical linguistics. Paraphyletic groups are identified by a combination of synapomorphies and symplesiomorphies. If many subgroups are missing from the named group, it is said to be polyparaphyletic. The term received currency during the debates of the 1960s and 1970s accompanying the rise of cladistics, having been coined by zoologist Willi Hennig to apply to well-known taxa like Reptilia (reptiles), which is paraphyletic with respect to birds. Reptilia contains the last common ancestor of reptiles and all descendants of that ancest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
