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Choptank Formation
The Choptank Formation is a geologic formation in Virginia and Maryland. It preserves fossils dating from the Miocene epoch of the Neogene period. Fossils The Choptank Formation is extremely fossiliferous. Some of the fossil species represented include the following: Sharks *''Otodus megalodon'' *''Carcharodon hastalis'' *'' Isurus oxyrhincus'' *Carcharomodus escheri *'' Physogaleus contortus'' *''Galeocerdo aduncus'' *''Carcharhinus'' *''Hemipristis serra'' *'' Squatina sp.'' *'' Notorhyncus cepedianus'' *''Carcharias'' *'' Isurus retroflexus'' *'' Parotodus benedeni'' *''Alopias vulpinus'' *'' Alopias grandis'' *''Cetorhinus'' *'' Negaprion brevirostris'' *''Rhizoprionodon'' *'' Sphryna laevissima'' Rays and Other Cartilaginous Fish *''Aetobatus arcuatus'' *'' Pteromyaleus sp.'' *''Dasyatis rugosa'' *''Dasyatis probsti'' *'' Pinthicus stenodon'' Fish *''Acipenseridae indet.'' *''Opsanus sp.'' *''Serranidae sp.'' *'' Pogonias sp.'' *''Sciaenops sp.'' *''Tautoga sp.'' *''Acanth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chesapecten
''Chesapecten'' is an extinct genus of scallop known from marine strata from the early Miocene to the early Pleistocene of the Eastern United States. It flourished in the shallow seas along the Mid-Atlantic during this period. Other scallops lived at the same time, but Chesapectens were the most abundant. Physical Description Like some other large scallops, the shells of ''Chesapecten'' are characterized by a pattern of wide ribs which radiate outward from the apex of the shell. A distinctive feature of ''Chesapecten'' is that the radial ribs on its shell are crossed by much smaller, rough, concentric ribs, which follow the contours of the edges of the shell (are "conmarginal"). The left valve of ''Chesapecten'' is more convex than the right valve. The adductor muscle scar is large and rounded. Distribution The geographical distribution of ''Chesapecten'' is limited to the Atlantic coastal plain of North America, where it can be found as far south as Florida, and as far ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galeocerdo Aduncus
''Galeocerdo'' is a genus of requiem sharks that have lived since the Paleocene epoch. While these sharks were formerly diverse, only ''G. cuvier'' (the modern tiger shark) survives today. Species Species in the genus ''Galeocerdo'' include: * †''Galeocerdo aduncus ''Galeocerdo'' is a genus of requiem sharks that have lived since the Paleocene epoch. While these sharks were formerly diverse, only ''G. cuvier'' (the modern tiger shark) survives today. Species Species in the genus ''Galeocerdo'' include: ...'' * †'' Galeocerdo alabamensis'' * †'' Galeocerdo clarkensis'' * '' Galeocerdo cuvier'' * †'' Galeocerdo denticulatus'' * †'' Galeocerdo eaglesomi'' * †'' Galeocerdo gibberulus'' * †'' Galeocerdo latidens'' * †'' Galeocerdo mayumbensis'' * †'' Galeocerdo minor'' * †'' Galeocerdo mixtus'' * †'' Galeocerdo productus'' References {{Taxonbar, from=Q2186811 Shark genera Taxa named by Johannes Peter Müller Taxa named by Friedrich Gustav Ja ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphyrna
''Sphyrna'' (from the Greek word σφῦρα, "hammer") is a genus of hammerhead sharks with a cosmopolitan distribution in the world's oceans. Members of ''Sphyrna'' have a tendency to inhabit coastal waters along the intertidal zone rather than the open ocean, as their prey such as invertebrates, fish, rays, small crustaceans, and other benthic organisms hide in the sands and sediment along these zones. Members of ''Sphyrna'' are also known by synonyms such as ''Zygaena'', ''Cestracion'', and ''Sphyrichthys''. The earliest species described of this genus was ''Sphyrna zygaena'' by Carl Linnaeus in 1758, while the latest described member, '' Sphyrna gilberti'', was discovered and described in 2013. Species The recognized species in this genus are:Martin, R. Aidan. (February 24, 1998)Recent Changes in Hammerhead Taxonomy ''ReefQuest Centre for Shark Research''. Retrieved on October 18, 2008. ;Extant * '' Sphyrna corona'' ( S. Springer, 1940) (scalloped bonnethead) * '' Sphyrn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhizoprionodon
''Rhizoprionodon'' is a genus of requiem sharks, and part of the family Carcharhinidae, commonly known as sharpnose sharks because of their long, pointed snouts. Species * '' Rhizoprionodon acutus'' ( Rüppell, 1837) (milk shark) * '' Rhizoprionodon lalandii'' ( J. P. Müller & Henle, 1839) (Brazilian sharpnose shark) * '' Rhizoprionodon longurio'' ( D. S. Jordan & C. H. Gilbert, 1882) (Pacific sharpnose shark) * '' Rhizoprionodon oligolinx'' V. G. Springer, 1964 (grey sharpnose shark) * '' Rhizoprionodon porosus'' ( Poey, 1861) (Caribbean sharpnose shark) * '' Rhizoprionodon taylori'' ( Ogilby, 1915) (Australian sharpnose shark) * '' Rhizoprionodon terraenovae'' ( J. Richardson, 1836) (Atlantic sharpnose shark) See also * List of sharks Shark is the naming term of all members of Selachimorpha suborder in the subclass Elasmobranchii, in the class Chondrichthyes. The Elasmobranchii also include rays and skates; the Chondrichthyes also include Chimaeras. The first shark ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Negaprion Brevirostris
The lemon shark (''Negaprion brevirostris'') is a species of shark from the family Carcharhinidae and is classified as a Vulnerable species by the International Union for the Conservation of Nature. Lemon sharks can grow to in length. They are often found in shallow subtropical waters and are known to inhabit and return to specific nursery sites for breeding. Often feeding at night, these sharks use electroreceptors to find their main source of prey: fish. Lemon sharks enjoy the many benefits of group living such as enhanced communication, courtship, predatory behavior, and protection. This species of shark gives birth to live young, and the females are polyandrous and have a biennial reproductive cycle. Lemon sharks are not thought to be a large threat to humans; there have been 10 recorded bites, none of which were life-threatening. The lemon shark's life span is unknown, but the average shark is 25 to 30 years old. Taxonomy The lemon shark was first named and described in 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cetorhinus
The basking shark (''Cetorhinus maximus'') is the second-largest living shark and fish, after the whale shark, and one of three plankton-eating shark species, along with the whale shark and megamouth shark. Adults typically reach in length. It is usually greyish-brown, with mottled skin, with the inside of the mouth being white in color. The caudal fin has a strong lateral keel and a crescent shape. Other common names include bone shark, elephant shark, sail-fish, and sun-fish. In Orkney, it is commonly known as hoe-mother (sometimes contracted to homer), meaning "the mother of the pickled dog-fish". The basking shark is a cosmopolitan migratory species, found in all the world's temperate oceans. A slow-moving filter feeder, its common name derives from its habit of feeding at the surface, appearing to be basking in the warmer water there. It has anatomical adaptations for filter-feeding, such as a greatly enlarged mouth and highly developed gill rakers. Its snout is conic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alopias Grandis
''Alopias grandis'' is a species of giant thresher shark from the Miocene. Estimates calculated from teeth comparisons suggest the living animal was comparable in size to the extant great white shark. Remains generally consist of teeth, which have been found in the United States in the Calvert Formation of Virginia and Maryland, and in Beaufort County, South Carolina. They have also been found in the Miocene of Malta.Godfrey, S. J. (Ed.). (2018). ''The Geology and Vertebrate Paleontology of Calvert Cliffs, Maryland, USA''. Smithsonian Institution Scholarly Press. It is unlikely it possessed the elongated tail lobe of modern thresher sharks. Some specimens in the Burdigalian The Burdigalian is, in the geologic timescale, an age (geology), age or stage (stratigraphy), stage in the early Miocene. It spans the time between 20.43 ± 0.05 annum, Ma and 15.97 ± 0.05 Ma (million years ago). Preceded by the Aquitanian (sta ... show the beginnings of serrations, which are presumably tra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alopias Vulpinus
The common thresher (''Alopias vulpinus''), also known as Atlantic thresher, is the largest species of thresher shark, family Alopiidae, reaching some in length. About half of its length consists of the elongated upper lobe of its caudal fin. With a streamlined body, short pointed snout, and modestly sized eyes, the common thresher resembles (and has often been confused with) the pelagic thresher (''A. pelagicus''). It can be distinguished from the latter species by the white of its belly extending in a band over the bases of its pectoral fins. The common thresher is distributed worldwide in tropical and temperate waters, though it prefers cooler temperatures. It can be found both close to shore and in the open ocean, from the surface to a depth of . It is seasonally migratory and spends summers at lower latitudes. The long tail of the common thresher, the source of many fanciful tales through history, is used in a whip-like fashion to deliver incapacitating blows to its prey. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parotodus
''Parotodus'', commonly known as the false-toothed mako shark (or false mako shark), is an extinct genus of mackerel shark that lived approximately 53 to one million years ago during the Eocene and Pleistocene epochs. Its teeth, which are found worldwide, are often prized by fossil collectors due to their rarity. The scarcity of fossils is because ''Parotodus'' likely primarily inhabited open oceans far away from the continents. Description Initially appearing as a small shark, ''Parotodus'' gradually increased in size over geologic time and by the Neogene period became one of the largest sharks of its time. A 1999 study estimated the genus to have measured up to in length. The teeth of ''Parotodus'' are distinctively curved and rarely show feeding damage, which suggests that it mainly preyed on soft-bodied animals. Paleontologists speculate that this included other sharks, including the contemporaneous Megalodon. Classification Due to the general scarcity and ambiguity of foss ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isurus Paucus
The longfin mako shark (''Isurus paucus'') is a species of mackerel shark in the family Lamnidae, with a probable worldwide distribution in temperate and tropical waters. An uncommon species, it is typically lumped together under the name "mako" with its better-known relative, the shortfin mako shark (''I. oxyrinchus''). The longfin mako is a pelagic species found in moderately deep water, having been reported to a depth of . Growing to a maximum length of , the slimmer build and long, broad pectoral fins of this shark suggest that it is a slower and less active swimmer than the shortfin mako. Longfin mako sharks are predators that feed on small schooling bony fishes and cephalopods. Whether this shark is capable of elevating its body temperature above that of the surrounding water like the other members of its family is uncertain, though it possesses the requisite physiological adaptations. Reproduction in this species is aplacental viviparous, meaning the embryos hatch from egg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carcharias
''Carcharias'' is a genus of sand tiger sharks belonging to the family Odontaspididae. Once bearing many prehistoric species, all have gone extinct with the exception of the critically endangered sand tiger shark. Description ''Carcharias'' are 2.5 m long on average. The maximum weight of the shark is 158.8 kg. Differentiating species of sharks is usually done by locating and measuring their fins. The second dorsal fin and the anal fin of ''Carcharias'' are very large. In fact, they are 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. The teeth are smooth with no ridges. The tail is one third of the entire body size. Diet ''Carcharias'' species hunt bony fish, small sharks, rays, squids, crabs, and lobsters. Habitat Sand tiger sharks live in water depths ranging from 0 to 190 meters. They are found in the Pacific, Atlantic, and Indian oceans. They are commonl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Broadnose Sevengill Shark
The broadnose sevengill shark (''Notorynchus cepedianus'') is the only extant member of the genus ''Notorynchus'', in the family Hexanchidae. It is recognizable because of its seven gill slits, while most shark species have five gill slits, with the exception of the members of the order Hexanchiformes and the sixgill sawshark. This shark has a large, thick body, with a broad head and blunt snout. The top jaw has jagged, cusped teeth and the bottom jaw has comb-shaped teeth. Its single dorsal fin is set far back along the spine towards the caudal fin, and is behind the pelvic fins. In this shark the upper caudal fin is much longer than the lower, and is slightly notched near the tip. Like many sharks, this sevengill is counter-shaded. Its dorsal surface is silver-gray to brown in order to blend with the dark water and substrate when viewed from above. In counter to this, its ventral surface is very pale, blending with the sunlit water when viewed from below. The body and fins are c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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