The Cuban naturalist Felipe Poey published the first description of the blacknose shark in 1860 as "Squalus acronotus", in his "Memorias sobre la historia natural de la Isla de Cuba". Later authors moved this species to the genus "Carcharhinus". The type specimen was a 98-cm (3.2-ft)-long male caught off Cuba. Based on morphological data, Jack Garrick suggested in 1982 that the blacknose shark has a sister relationship to a group containing the whitecheek shark ("C. dussumieri") and the blackspot shark ("C. sealei"), while Leonard Compagno proposed in 1988 that this shark belongs in a group with five other species, including the silky shark ("C.
Taxonomy and phylogeny
Blacknose shark
Blacknose shark | Taxonomy and phylogeny
Felipe Poey Felipe Poey. Felipe Poey Cuban naturalist Felipe Poey
what is the scientific name of blacknose shark?
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Carcharhinus acronotus
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where is it commonly found?
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Tropical and subtropical waters of the western Atlantic Ocean
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who described it first?
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The Cuban naturalist Felipe Poey published the first description of the blacknose shark in 1860 as "Squalus acronotus", in his "Memorias sobre la historia natural de la Isla de Cuba". Later authors moved this species to the genus "Carcharhinus". The type specimen was a 98-cm (3.2-ft)-long male caught off Cuba. Based on morphological data, Jack Garrick suggested in 1982 that the blacknose shark has a sister relationship to a group containing the whitecheek shark ("C. dussumieri") and the blackspot shark ("C. sealei"), while Leonard Compagno proposed in 1988 that this shark belongs in a group with five other species, including the silky shark ("C.
Blacknose shark | Taxonomy and phylogeny
falciformis") and the blacktip reef shark ("C. melanopterus"). Molecular analyses have been similarly equivocal regarding the blacknose shark's phylogenetic relationships: Gavin Naylor's 1992 allozyme analysis found this species to be the most basal member of "Carcharhinus", while Mine Dosay-Abkulut's 2008 ribosomal DNA analysis indicated affinity between it and the blacktip shark ("C. limbatus") or the smalltail shark ("C. porosus"). The whitenose shark ("Nasolamia velox"), found along the tropical western coast of the Americas, may be descended from blacknose sharks that experienced the teratogenic effects of incipient cyclopia.
Blacknose shark | Taxonomy and phylogeny
The first scientific description of the porbeagle was authored by French naturalist Pierre Joseph Bonnaterre in the 1788 "Tableau encyclopédique et methodique des trois règnes de la nature", and based on an earlier 1769 account by Welsh naturalist Thomas Pennant. Bonnaterre named the shark "Squalus nasus", the specific epithet "nasus" being Latin for "nose". In 1816, French naturalist Georges Cuvier placed the porbeagle into its own subgenus, "Lamna", which later authors elevated to the rank of full genus.
Porbeagle | Taxonomy
The first dorsal fin is small and somewhat sickle-shaped, with a pointed apex and a short, free, rear tip; its origin lies over the free rear tips of the pectoral fins. The second dorsal fin is relatively large, though still less than half the height of the first. No ridge is seen between the dorsal fins. The pectoral fins are short and tapered. The body is covered with overlapping dermal denticles that bear five to seven longitudinal ridges (three in very young individuals) leading to three to five marginal teeth. The coloration is yellowish to greenish-gray or brown above and white to yellow below.
Blacknose shark | Description
This suggests that Indo-Pacific blacktip sharks are descended from those in the eastern Atlantic, while the western Atlantic sharks became isolated by the widening Atlantic Ocean on one side and the formation of the Isthmus of Panama on the other. Blacktip sharks from these two regions differ in morphology, coloration, and life history characteristics, and the eastern Atlantic lineage may merit species status. Fossil teeth belonging to this species have been found in Early Miocene (23–16 Ma) deposits in Delaware and Florida.
Blacktip shark | Phylogeny and evolution
The blacktip shark was first described by French zoologist Achille Valenciennes as "Carcharias (Prionodon) limbatus" in Johannes Müller and Friedrich Henle's 1839 "Systematische Beschreibung der Plagiostomen". The type specimens were two individuals caught off Martinique, both of which have since been lost. Later authors moved this species to the genus "Carcharhinus". The specific epithet "limbatus" is Latin for "bordered", referring to the black edges of this shark's fins. Other common names used for the blacktip shark include blackfin shark, blacktip whaler, common or small blacktip shark, grey shark, and spotfin ground shark.
Blacktip shark | Taxonomy
In 1996, Siverson synonymized "Cretolamna woodwardi" with "Pseudoisurus tomosus" after finding that their referred type specimens pertained to the same species. Later in 1999, Siverson reassessed the taxonomy of "Pseudoisurus tomosus" and concluded that its syntypes are lost, making it a "nomen dubium". He also found that the former "Cretalamna woodwardi" actually represents two distinct genera of sharks, which was also the likely case for "Pseudoisurus tomosus"- The first was "C. ricki" (which he already described using WAM.96.4.45), and the other was assigned the taxon "Dwardius woodwardi".
Cardabiodon | Discovery and naming
French naturalist Charles Alexandre Lesueur published the first scientific description of the dusky shark in an 1818 issue of "Journal of the Academy of Natural Sciences of Philadelphia". He placed it in the genus "Squalus" and gave it the specific epithet "obscurus" (Latin for "dark" or "dim"), referring to its coloration. Subsequent authors have recognized this species as belonging to the genus "Carcharhinus". Lesueur did not designate a type specimen, though he was presumably working from a shark caught in North American waters. Many early sources gave the scientific name of the dusky shark as "Carcharias" (later "Carcharhinus") "lamiella", which originated from an 1882 account by David Starr Jordan and Charles Henry Gilbert.
Dusky shark | Taxonomy
The first known specimen of the smoothtooth blacktip shark was a 75-cm-long, immature male caught by Wilhelm Hein in 1902 and deposited at the Naturhistorisches Museum in Vienna. The location was recorded as the Gulf of Aden near "Gischin", which likely refers to the town of Qishn in eastern Yemen. In 1985, the shark was examined and described as a new species by New Zealand ichthyologist Jack Garrick in a National Oceanic and Atmospheric Administration technical report. He gave it the specific epithet "leiodon", from the Greek "leios" meaning "smooth", and "odon" meaning "tooth". This species was known only by the single specimen until 2008, when fishery surveys in Kuwait uncovered several more specimens.
Smoothtooth blacktip shark | Taxonomy and phylogeny
The species was redescribed twice more by Day in 1876 and Chu and Chen in 1958. Being Swainson is the first author to correctly describe the fish, even though he initially ascribed it to the wrong genus, the ICZN recognises "Alepes melanoptera" as the correct name, and the rest as invalid junior synonyms. Such synonymy is common in the genus "Alepes" due to the abundance of similar genera. The specific name 'melanoptera' literally means 'black wing' in Greek; a reference to its distinctive colouration.
Blackfin scad | Taxonomy and naming
The first scientific description of the daggernose shark, as "Carcharias oxyrhynchus", was published by German biologists Johannes Peter Müller and Friedrich Gustav Jakob Henle in their 1839 "Systematische Beschreibung der Plagiostomen". They chose the specific epithet "oxyrhynchus", from the Greek ' ("sharp" or "pointed") and ' ("nose"). In 1862, American ichthyologist Theodore Gill coined the genius "Isogomphodon" for this species, from the Greek ' ("equal"), ' ("nail" or "peg"), and "" ("tooth"). However, "Isogomphodon" was subsequently relegated to being a synonym of "Carcharhinus", until it was resurrected by shark authority Stewart Springer in 1950. Regardless of its taxonomic validity, "Isogomphodon", along with the genera "Nasolamia" and "Prionace", is closely related to "Carcharhinus".
Daggernose shark | Taxonomy and phylogeny
The great white shark was one of the many amphibia originally described by Carl Linnaeus in his landmark 1758 10th edition of "Systema Naturae", with its first scientific name, "Squalus carcharias". Later, Sir Andrew Smith gave it "Carcharodon" as its generic name in 1833, and also in 1873. The generic name was identified with Linnaeus' specific name and the current scientific name, "Carcharodon carcharias", was finalized. "Carcharodon" comes from the Ancient Greek words (, 'sharp' or 'jagged'), and (), (, 'tooth').
Great white shark | Taxonomy
Italian naturalist Camillo Ranzani published the first scientific description of the smalltail shark in an 1839 volume of "Novi Commentarii Academiae Scientiarum Instituti Bononiensis". He named the new shark "Carcharias porosus" from the Greek "porus" ("pore"), referring to the prominent pores behind its eyes. The type specimen, a -long male from Brazil, has since been lost. This species was moved to the genus "Carcharhinus" by later authors. Its Trinidadian name is puppy shark. The evolutionary relationships of the smalltail shark are uncertain. Based on morphology, Jack Garrick in 1982 and Leonard Compagno in 1988 tentatively placed it in a group defined by the whitecheek shark ("C.
Smalltail shark | Taxonomy and phylogeny
The first scientific description of the bluntnose sixgill shark was authored in 1788 by Pierre Joseph Bonnaterre. As a member of the family Hexanchidae, it has more close relatives in the fossil record than living relatives. The related living species include the dogfish, the Greenland shark, and other six- and seven-gilled sharks. Some of the shark's relatives date back 200 million years. This shark is a notable species due to both its primitive and current physical characteristics.
Bluntnose sixgill shark | Taxonomy
The first known specimen of the black dogfish was collected near Julianehåb in Greenland and described by Danish zoologist Johannes Reinhardt in his 1825 "Ichthyologiske bidrag". Reinhardt gave it the name "Spinax fabricii" in honor of missionary and naturalist Otto Fabricius, who pioneered the study of Greenlandic fishes. German biologists Johannes Müller and Jakob Henle, in their 1839–41 "Systematische Beschreibung der Plagiostomen", created the new genus "Centroscyllium" for this species. According to the IUCN, further taxonomic investigation is required to confirm the black dogfish in the North Atlantic and the southeastern Atlantic represent the same species. A 2010 phylogenetic study by Nicolas Straube and colleagues, based on nuclear and mitochondrial DNA, found the black dogfish is the sister species of the whitefin dogfish ("C.
Black dogfish | Taxonomy and phylogeny
The zoologist Ludwig Döderlein first identified, described, and classified the frilled shark as a discrete species of shark. After three years (1879–1881) of marine research in Japan, Döderlein took two specimen sharks to Vienna, but lost the taxonomic manuscript of the research. Three years later, in the "Bulletin of the Essex Institute" (vol. XVI, 1884) the zoologist Samuel Garman published the first taxonomy of the frilled shark, based upon his observations, measurements, and descriptions of a –long female shark from Sagami Bay, Japan. In the article “An Extraordinary Shark” Garman classified the new species of shark within its own genus and family, and named it "Chlamydoselachus anguineus" (eel-like shark with frills).
Frilled shark | Taxonomy and phylogeny
The hardnose shark was described by German biologists Johannes Müller and Jakob Henle in their 1839 "Systematische Beschreibung der Plagiostomen". They named it "Carcharias (Hypoprion) macloti" in honour of Heinrich Christian Macklot, who collected the type specimen from New Guinea. In 1862, American ichthyologist Theodore Gill elevated "Hypoprion" to the rank of full genus, with "C. macloti" as the type species. In 1985, Jack Garrick synonymised "Hypoprion" with "Carcharhinus". This species may also be called Maclot's shark.
Hardnose shark | Taxonomy
Because of its very patchy range, the copper shark has been scientifically described several times from different locales. The earliest valid description is presently considered to be British zoologist Albert Günther's account of "Carcharias brachyurus" in the 1870 eighth volume of "Catalogue of the fishes in the British Museum". The earliest name was once thought to be Auguste Duméril's 1865 "Carcharias remotus", until it was found that the type specimen associated with that name is actually a blacknose shark ("C. acronotus"). Thus, this shark was often referred to as "C. remotus" in older literature. An even earlier name, Richard Owen's 1853 "Galeolamna greyi", is of questionable taxonomic status as it was based solely on a set of now-destroyed jaws that may or may not have belonged to a copper shark.
Copper shark | Taxonomy
The first scientific name applied to the leopard shark was "Triakis californica", coined by British zoologist John Edward Gray in the 1851 "List of the specimens of fish in the collection of the British Museum". However, Gray did not furnish the name with a proper description, rendering it a "nomen nudum". In December 1854, American ichthyologist William Orville Ayres gave a lecture describing the species as "Mustelus felis", which included the first scientific description of the species. His lecture was reprinted first in "The Pacific", a San Francisco newspaper, and then in the journal "Proceedings of the California Academy of Natural Sciences".
Leopard shark | Taxonomy and phylogeny
"Cretalamna" was first described by Swiss naturalist Louis Agassiz using five teeth previously identified as the common smooth-hound and collected by English paleontologist Gideon Mantell from the Southerham Grey Pit near Lewes, East Sussex. In his 1835 publication "Rapport sur les poissons fossiles découverts en Angleterre", he reidentified them as a new species of porbeagle shark under the taxon "Lamna appendiculata". In 1843, Agassiz published "Recherches sur les poissons fossiles", which reexamined Mantell's five teeth. Using them, eight additional teeth collected by Mantell, and twenty more teeth collected by various paleontologists in various locations (One tooth found by the 3rd Earl of Enniskillen from the Speeton Clay in Yorkshire; one tooth of the collection of a Strasbourg Museum from an unspecified location; one tooth of the collection of the from the Marly Chalk near Cambridge; and six teeth of the collection of German paleontologist Heinrich Georg Bronn from chalk around Aachen), he described a species whose teeth had thick bulged roots, lateral cusplets, and extreme variability.
Cretalamna | Research History
longimanus"). Dusky shark teeth have also been recovered from the vicinity of two baleen whales in North Carolina, one preserved in Goose Creek Limestone dating to the Late Pliocene ("c." 3.5 Ma), and the other in mud dating to the Pleistocene-Holocene ("c." 12,000 years ago). In 1982, Jack Garrick published a phylogenetic analysis of "Carcharhinus" based on morphology, in which he placed the dusky shark and the Galapagos shark ("C. galapagensis") at the center of the "obscurus group". The group consisted of large, triangular-toothed sharks with a ridge between the dorsal fins, and also included the bignose shark ("C. altimus"), the Caribbean reef shark ("C.
Dusky shark | Phylogeny and evolution
An extinct relative, "I. acuarius", dates back to the Middle Eocene (45 Ma).
Daggernose shark | Taxonomy and phylogeny
The longnose pygmy shark was described by American zoologist Henry Weed Fowler in a 1934 volume of "Proceedings of the Academy of Natural Sciences of Philadelphia", based on a long female collected off Point Ocean Beach in Durban, South Africa. Fowler had originally thought the shark to belong to the genus "Heteroscymnus" (a junior synonym of "Somniosus"), and thus he created for it the new genus "Heteroscymnoides" from the Greek "oidos" ("resemblance"). He gave it the specific epithet "marleyi" in honor of Harold Walter Bell-Marley, and his contributions to the study of South African fishes. The relationship between "Heteroscymnoides" and the rest of its family is uncertain.
Longnose pygmy shark | Taxonomy
Teeth apparently belonging to the hardnose shark have been recovered from the Pungo River and Yorktown Formations in the United States, and from the Pirabas Formation in Brazil. The earliest of these fossils date to the Lower Miocene (23–16 Ma).
Hardnose shark | Phylogeny and evolution
The first scientific description of the night shark was published by Cuban zoologist Felipe Poey in 1868, as part of a series of papers entitled "Repertorio fisico-natural de la isla de Cuba". He based his description on a single set of jaws and gave it the name "Hypoprion signatus". In 1973, Leonard Compagno synonymized the genus "Hypoprion" with "Carcharhinus". No type specimen has been designated for this species. Its common name is because it is mostly captured at night.
Night shark | Taxonomy
The first efforts to determine the evolutionary relationships of the copper shark were based on morphology and returned inconclusive results: in 1982 Jack Garrick placed it by itself as a grouping within "Carcharhinus", while in 1988 Leonard Compagno placed it in an informal "transitional group" that also contained the blacknose shark ("C. acronotus"), the blacktip reef shark ("C. melanopterus"), the nervous shark ("C. cautus"), the silky shark ("C. falciformis"), and the night shark ("C. signatus"). Gavin Naylor's 1992 allozyme study concluded that the closest relative of the copper shark is the spinner shark ("C. brevipinna"), but could not resolve their wider relationships with the rest of the genus.
Copper shark | Phylogeny and evolution
melanopterus"). Leonard Compagno in 1988 tentatively grouped these two species with the blacknose shark ("C. acronotus"), the copper shark ("C. brachyurus"), the silky shark ("C. falciformis"), and the night shark ("C. signatus"). The close relationship between the nervous and blacktip reef sharks was upheld in a 1992 phylogenetic study by Shane Lavery, based on allozymes, and again in a 2011 study by Ximena Vélez-Zuazoa and Ingi Agnarsson, based on nuclear and mitochondrial genes.
Nervous shark | Taxonomy and phylogeny
The blacknose shark ("Carcharhinus acronotus") is a species of requiem shark, belonging to the family Carcharhinidae, common in the tropical and subtropical waters of the western Atlantic Ocean. This species generally inhabits coastal seagrass, sand, or rubble habitats, with adults preferring deeper water than juveniles. A small shark typically measuring long, the blacknose has a typical streamlined "requiem shark" shape with a long, rounded snout, large eyes, and a small first dorsal fin. Its common name comes from a characteristic black blotch on the tip of its snout, though this may be indistinct in older individuals. Blacknose sharks feed primarily on small bony fishes and cephalopods, and in turn fall prey to larger sharks.
Blacknose shark | Introduction
The closest relatives of the blacktip shark were originally thought to be the graceful shark ("C. amblyrhynchoides") and the spinner shark ("C. brevipinna"), due to similarities in morphology and behavior. However, this interpretation has not been borne out by studies of mitochondrial and ribosomal DNA, which instead suggest affinity with the blacknose shark ("C. acronotus"). More work is required to fully resolve the relationship between the blacktip shark and other "Carcharhinus" species. Analysis of mitochondrial DNA has also revealed two distinct lineages within this species, one occupying the western Atlantic and the other occupying the eastern Atlantic, Indian, and Pacific Oceans.
Blacktip shark | Phylogeny and evolution
menisorrah". The blacktail reef shark ("C. wheeleri"), native to the western Indian Ocean, is now regarded as the same species as the grey reef shark by most authors. It was originally distinguished from the grey reef shark by a white tip on the first dorsal fin, a shorter snout, and one fewer upper tooth row on each side. Based on morphological characters, vertebral counts, and tooth shapes, Garrick (1982) concluded the grey reef shark is most closely related to the silvertip shark ("C. albimarginatus"). This interpretation was supported by a 1992 allozyme phylogenetic analysis by Lavery.
Grey reef shark | Taxonomy and phylogeny
Dutch ichthyologist Pieter Bleeker first described the grey reef shark in 1856 as "Carcharias (Prionodon) amblyrhynchos", in the scientific journal "Natuurkundig Tijdschrift voor Nederlandsch-Indië". Later authors moved this species to the genus "Carcharhinus". The type specimen was a -long female from the Java Sea. Other common names used for this shark around the world include black-vee whaler, bronze whaler, Fowler's whaler shark, graceful shark, graceful whaler shark, grey shark, grey whaler shark, longnose blacktail shark, school shark, and shortnose blacktail shark. Some of these names are also applied to other species. In older literature, the scientific name of this species was often given as "C.
Grey reef shark | Taxonomy and phylogeny
French naturalists Jean René Constant Quoy and Joseph Paul Gaimard originally described the blacktip reef shark during the 1817–1820 exploratory voyage of the corvette "Uranie". In 1824, their account was published as part of "Voyage autour du monde...sur les corvettes de S.M. l'Uranie et la Physicienne", Louis de Freycinet's 13-volume report on the voyage. The type specimen was a -long juvenile male caught off the island of Waigeo, west of New Guinea. Quoy and Gaimard chose the name "Carcharias melanopterus", from the Greek "melas" meaning "black" and "pteron" meaning "fin" or "wing", in reference to this shark's prominent fin markings.
Blacktip reef shark | Taxonomy
The spinner shark was originally described as "Carcharias (Aprion) brevipinna" by Johannes Peter Müller and Friedrich Gustav Jakob Henle in their 1839 "Systematische Beschreibung der Plagiostomen", based on the mounted skin of a 79-cm-long specimen collected off Java. This species was subsequently moved to the genera "Aprion", "Squalus", and "Aprionodon" before being placed within the genus "Carcharhinus". The tooth shape and coloration of this species varies significantly with age and between geographical regions, which caused much taxonomic confusion. Other common names include black-tipped shark, great blacktip shark, inkytail shark, large blacktip shark, long-nose grey shark, longnose grey whaler, and smoothfang shark.
Spinner shark | Taxonomy and phylogeny
German physicians and biologists Johannes Peter Müller and Friedrich Gustav Jakob Henle originally described the dark shyshark in their 1838–41 "Systematische Beschreibung der Plagiostomen", based on five specimens caught off the Cape of Good Hope and deposited in the Rijksmuseum van Natuurlijke Historie in Leiden, The Netherlands. Because of the shark's ornate coloration, they gave it the specific epithet "pictum" from the Latin for "painted". Originally placed in the now-obsolete genus "Scyllium", subsequent authors moved this species to the genus "Haploblepharus", coined by American zoologist Samuel Garman in 1913. The dark shyshark was often regarded to be the same as the puffadder shyshark ("H.
Dark shyshark | Taxonomy and phylogeny
The first scientific description of the spadenose shark was published in 1838 by the German biologists Johannes Peter Müller and Friedrich Gustav Jakob Henle, in their "Systematische Beschreibung der Plagiostomen". The holotype is presumed to be a -long stuffed specimen in the Zoologisches Museum of Berlin. The generic name "Scoliodon" is derived from the Greek "skolex" ("worm") and "odon" ("tooth"), while the specific epithet "laticaudus" comes from the Latin "latus" ("broad" or "wide") and "cauda" ("tail"). Other common names used for this species include Indian dog shark, sharp-nosed shark, trowel-nose shark, and yellow dog shark. Phylogenetic analyses based on morphological and molecular data indicate the spadenose shark is one of the most basal members of its family, along with the related genus "Rhizoprionodon" and "Galeocerdo", the tiger shark.
Spadenose shark | Taxonomy and phylogeny
It was first described by C. C. Wallace in 1994 in the Indo-Pacific ocean as "Acropora lokani".
Acropora lokani | Taxonomy
The first specimen of the taillight shark was collected by the Cape Town trawler "Arum" in 1963 and was initially identified as a longnose pygmy shark before being recognized as a hitherto unknown species. The genus name "Euprotomicroides" comes from this shark's resemblance to the pygmy shark. The specific epithet "zantedeschia" is derived from "Zantedeschia aethiopica", a species of arum lily for which the trawler "Arum" was named. Phylogenetic analysis based on dentition indicates that the taillight shark is the most basal member of its family and is sister to the clade containing all other dalatiid species. Although no definitive fossil remains have been found, the taillight shark may have evolved in the early Paleocene epoch (65.5–55.8 million years ago - Mya), as part of a larger adaptive radiation of dogfish sharks into midwater habitats.
Taillight shark | Taxonomy and phylogeny
Like most other members of its genus, the phylogenetic position of the blacktip reef shark remains indeterminate. Based on morphology, Jack Garrick proposed in 1982 that the closest relative of the blacktip reef shark was the nervous shark ("C. cautus"). Leonard Compagno's 1988 morphological analysis suggested affinity not only between this species and the nervous shark, but also four other species, and could not resolve their relationships further. A 1998 allozyme analysis by Gavin Naylor again yielded ambiguous results, finding that the blacktip reef shark forms a polytomy (irresolvable group) with 10 other "Carcharhinus" species.
Blacktip reef shark | Phylogeny
The evolutionary relationships of the hardnose shark have not been fully resolved. In a 1988 study based on morphology, Leonard Compagno tentatively grouped the hardnose shark with the Borneo shark ("C. borneensis"), whitecheek shark ("C. dussumieri"), Pondicherry shark ("C. hemiodon"), creek whaler ("C. fitzroyensis"), smalltail shark ("C. porosus"), blackspot shark ("C. sealei"), and spottail shark ("C. sorrah"). Results from molecular phylogenetic analyses have been inconsistent, with some supporting parts of Compagno's hypothesis: a 1992 study could not resolve the hardnose shark's position in detail, a 2011 study reported that it was close to the clade formed by the whitecheek and blackspot sharks, and a 2012 study concluded that it was the sister species of the Borneo shark.
Hardnose shark | Phylogeny and evolution
It was a 25–30 cm or 10-12 inches long "cladodont-toothed stethacanthid shark" The first material known from the genus were the prominent fin spines that curved anteriorly over the head of the animal. When first described in 1883 from the St. Louis Limestone, these remains were given the name "Physonemus falcatus". However, in 1985, fossils of a new type of condrichthyan from Montana were described that displayed a high degree of sexual dimorphism. The same spines that were previously named "P. falcatus" were found on one of the morphs, identified as the male due to the presence of valvae.
Falcatus | Description
It was first described by C. C. Wallace in 1994 in the North-East Indian Ocean, as "Acropora kosurini".
Acropora kosurini | Taxonomy
The species is widespread in deeper waters (samples off South Africa have been obtained from ~650 m) and occurs on a variety of shark species. Records are known both from cold from waters off Greenland, Britain, New Zealand, Chile and South Africa, as well as warmer waters off Spain, the Canary Islands, Australia, and in the Gulf of Mexico.
Anelasma | Distribution
dussumieri") and the blackspot shark ("C. sealei"). This grouping was equivocally supported by Gavin Naylor's 1992 allozyme-based phylogenetic analysis. Alternately, a 2011 phylogenetic study by Ximena Vélez-Zuazoa and Ingi Agnarsson, based on nuclear and mitochondrial genes, found close relationships between the smalltail shark, the daggernose shark ("Isogomphodon oxyrhynchus"), the blacknose shark ("C. acronotus"), and the finetooth shark ("C. isodon"). The Pacific smalltail shark ("C. cerdale") was once mistakenly synonymized with "C. porosus", until 2011 when José Castro resurrected it as a distinct taxon. An undescribed species closely similar to "C. porosus" is known from Southeast Asia.
Smalltail shark | Taxonomy and phylogeny
The first known specimens of the northern river shark, two newborn males from Papua New Guinea, were discovered by New Zealand ichthyologist Jack Garrick, after whom the species was eventually named. This shark was referred to as ""Glyphis" sp. C" until 2008, when it was formally described by Leonard Compagno, William White, and Peter R. Last in a Commonwealth Scientific and Industrial Research Organisation paper. The type specimen is a female long, collected from the East Alligator River, Kakadu National Park, Northern Territory.
Northern river shark | Taxonomy
Gymnothorax ocellatus is a moray eel found in coral reefs in the western Atlantic Ocean. It was first named by Louis Agassiz in 1831, and is also commonly known as the blackedge moray, Caribbean ocellated moray, conger, ocellated moray, spotted moray, sawtooth moray, white-spotted moray, or yellow cong.
Gymnothorax ocellatus | Introduction
The French biologist Charles Frédéric Girard published the first scientific description of the horn shark under the name "Cestracion francisci" in 1855, in the "Proceedings of the Academy of Natural Sciences of Philadelphia". This species was later placed in the genus "Gyropleurodus", which was eventually synonymized with the genus "Heterodontus". The specific epithet "francisci" is a reference to San Francisco, although the range of the horn shark does not extend that far north. The type specimen from Monterey Bay has since been lost. The scientific name for this species has been given erroneously as "Heterodontus californicus".
Horn shark | Taxonomy
The display consists of the shark hunching its back, lowering its pectoral fins, gaping its jaws, and swimming with an exaggerated side-to-side motion. Known parasites of this species include the copepods "Nesippus orientalis", "Perissopus dentatus", "Pandarus sinuatus", "Kroyeria sphyrnae", "Nemesis atlantica", and "Eudactylina spinifera", as well as tapeworms in the genera "Paraorygmatobothrium" and "Platybothrium".
Blacknose shark | Biology and ecology
perezi"), the sandbar shark ("C. plumbeus"), and the oceanic whitetip shark. This interpretation was largely upheld by Leonard Compagno in his 1988 phenetic study, and by Gavin Naylor in his 1992 allozyme sequence study. Naylor was able to further resolve the interrelationships of the "ridge-backed" branch of "Carcharhinus", finding that the dusky shark, Galapagos shark, oceanic whitetip shark, and blue shark ("Prionace glauca") comprise its most derived clade.
Dusky shark | Phylogeny and evolution
The whitetip reef shark was first described by the German naturalist Eduard Rüppell as "Carcharias obesus", in the 1837 "Fische des Rothen Meere" ("Fishes of the Red Sea"). His choice of the specific epithet "obesus" was curious, given that this shark is actually quite slender. Later in 1837, Johannes Müller and Friedrich Henle moved this species into its own genus "Triaenodon", from the Greek "triaena" meaning "trident", and "odon" meaning "tooth". As Rüppell did not originally designate a holotype, in 1960 a 31-cm-long specimen caught off Jeddah, Saudi Arabia, was made the species lectotype. Other common names for this shark include blunthead shark, light-tip shark, reef whitetip shark, and whitetip shark.
Whitetip reef shark | Taxonomy and phylogeny
The anatomic traits of body, muscle, and skeleton phylogenically include the frilled shark to the neoselachian clade (modern sharks and rays) which relates it to the cow shark, in the order "Hexanchiformes"; nonetheless, as a systematist of biology, the ichthyologist Shigeru Shirai proposed the "Chlamydoselachiformes" taxonomic order exclusively for the "C. anguinesis" and the "C. africana" species of frilled sharks. As a marine animal, the frilled shark is a living fossil because of its relatively unchanged anatomy and physique, since first appearing in the primeval seas of the Late Cretaceous (ca. 95 mya) and the Late Jurassic (150 mya) epochs.
Frilled shark | Taxonomy and phylogeny
The shark was first discovered by scientists from Tulane University that were conducting a study on sperm whales in 2010. In 2013, the National Oceanic and Atmospheric Administration identified it as a pocket shark, the first to be found in its region. A previously found specimen of a different pocket shark species was caught off the coast of Chile in 1979 and was used to identify the two different species due to their differences in size, vertebrae and numerous light-producing photophores.
Mollisquama mississippiensis | Discovery
The Caribbean reef shark was originally described as "Platypodon perezi" by Felipe Poey in 1876, in the scientific journal "Anales de la Sociedad Española de Historia Natural". The type specimens were six individuals caught off the coast of Cuba. The genus "Platypodon" was synonymized with "Carcharhinus" by later authors. Based on morphological similarities, Jack Garrick in 1982 grouped this species with the bignose shark ("C. altimus") and the sandbar shark ("C. plumbeus"), while Leonard Compagno in 1988 placed it as the sister species of the grey reef shark ("C. amblyrhynchos"). A phylogenetic analysis based on allozyme data, published by Gavin Naylor in 1992, indicated that the Caribbean reef shark is the sister taxon to a clade formed by the Galapagos shark ("C.
Caribbean reef shark | Taxonomy and phylogeny
This is the first confirmed case of hybridization among cartilaginous fishes.
Australian blacktip shark | Biology and ecology
Patchy records from around the world indicate the bignose shark probably has a circumglobal distribution in tropical and subtropical waters. In the Atlantic Ocean, it occurs from Delaware Bay to Brazil, in the Mediterranean Sea, and off West Africa. In the Indian Ocean, it is known in South Africa and Madagascar, the Red Sea, India, and the Maldives. In the Pacific Ocean, it has been recorded from China to Australia, around Hawaii, and from the Gulf of California to Ecuador. It is reportedly common off Florida, the Bahamas, and the West Indies, and rare off Brazil and in the Mediterranean.
Bignose shark | Distribution and habitat
In 2002, P. Mausfeld and D. Vrcibradic re-examined the holotype, which is the only known specimen. It is similar to "T. atlantica", but larger, and lacks well-developed keels on its dorsal scales. Therefore, they suggested that it was not the same as "T. atlantica" and that its original locality may have been correct. Although it may represent a valid species of southern African "Trachylepis", the name "Trachylepis punctatissima" is preoccupied by "Euprepes punctatissimus" A. Smith, 1849, also currently placed in "Trachylepis".
Noronha skink | 19th century
The tawny nurse shark was first described by French naturalist René-Primevère Lesson as "Scyllium ferrugineum", based on a long specimen from New Guinea. His short account was published in 1831 in "Voyage au tour du monde, sur la corvette La Coquille". A more detailed description, along with an illustration, was published by German naturalist Eduard Rüppell in 1837 as "Nebrius concolor", based on a specimen from the Red Sea. Both names were retained, often in separate genera ("Ginglymostoma" and "Nebrius" respectively), until they were synonymized by Leonard Compagno in 1984. Compagno recognized that the tooth shape differences used to separate these species were the result of differences in age, with "N.
Tawny nurse shark | Taxonomy and phylogeny
"Acropora abrolhosensis" was first described by John Veron in 1985 at Australian coral reefs.
Acropora abrolhosensis | Taxonomy
The first megamouth shark was captured on November 15, 1976, about 25 miles off the coast of Kāneohe, Hawaii, when it became entangled in the sea anchor of United States Navy ship "AFB-14". The species was identified as being of a new genus within the planktivorous shark species. Examination of the 4.5-m (14.7-ft), 750-kg (1,650-lb) specimen by Leighton Taylor showed it to be an entirely unknown type of shark, making it – along with the coelacanth – one of the more sensational discoveries in 20th-century ichthyology. The pectoral fin of the megamouth shark was studied, along with the skeletal and muscular system of the megamouth shark to show its phylogenetic relationship to the other two sharks.
Megamouth shark | Discovery
From that anatomy, Garman proposed that the frilled shark was related to the cladodont sharks of the "Cladoselache" genus that existed during the Devonian period (419–359 mya) in the Palaeozoic era (541–251 mya). In contrast to Garman's thesis, the ichthyologist Theodore Gill and the paleontologist Edward Drinker Cope, suggested that the frilled shark's evolutionary tree indicated relation to the Hybodontiformes (hybodonts), which were the dominant species of shark during the Mesozoic era (252–66 mya); and Cope categorized the "Chlamydoselachus anguineus" species to the fossil genus "Xenacanthus" that existed from the late Devonian period to the end of the Triassic period of the Mesozoic era.
Frilled shark | Taxonomy and phylogeny
A scientific description of the silky shark was first published by the German biologists Johannes Müller and Jakob Henle under the name "Carcharias (Prionodon) falciformis", in their 1839 "Systematische Beschreibung der Plagiostomen". Subsequent authors have assigned this species to the genus "Carcharhinus". Because Müller and Henle's type specimen was a 53-cm-long female fetus from Cuba, adult silky sharks were historically not recognized as "C. falciformis" and were described as a separate species, "Carcharhinus floridanus", by Henry Bigelow, William Schroeder, and Stewart Springer in 1943. Jack Garrick, Richard Backus, and Robert Gibbs, Jr. synonymized "C. floridanus" with "C. falciformis" in 1964.
Silky shark | Taxonomy
It was first described by C. C. Wallace in 1994 in the Indo-Pacific as "Acropora desalwii".
Acropora desalwii | Taxonomy
They are known from the paleogene of Morocco, France, Belgium, Russia, North Carolina, Georgia, Alabama,and Virginia. In the lower Nanjemoy Formation of Virginia, they are the most common fossil shark tooth. By the end of the Oligocene Epoch the genus is severely reduced, probably due to competition with other Carcharhiniformes like Carcharhinus.
Abdounia | Locations
Perhaps seen by Amerigo Vespucci in 1503, it was first formally described in 1839. Its subsequent taxonomic history has been complex, riddled with confusion with "Trachylepis maculata" and other species, homonyms, and other problems. The species is classified in the otherwise mostly African genus "Trachylepis" and is thought to have reached its island from Africa by rafting. The enigmatic "Trachylepis tschudii", supposedly from Peru, may well be the same species.
Noronha skink | Introduction
Constantine Samuel Rafinesque briefly described the blackmouth catshark in his 1810 "Caratteri di alcuni nuovi generi e nuove specie di animali e piante della Sicilia: con varie osservazioni sopra i medesimi", wherein he referenced the distinctive black interior of its mouth (from which the specific epithet "melastomus" is derived). No type specimen was designated. This species may also be called the black-mouthed dogfish. A 2005 phylogenetic analysis that included five "Galeus" species, based on mitochondrial and nuclear DNA, found that "G. melastomus" forms a clade with "G. murinus", apart from the clade of "G. eastmani", "G. gracilis", and "G. sauteri".
Blackmouth catshark | Taxonomy and phylogeny
The spined pygmy shark was one of many new species discovered during the course of the 1907–1910 Philippine Expedition of the U.S. Fish Commission Steamer "Albatross". It was described by American ichthyologists Hugh McCormick Smith and Lewis Radcliffe in a 1912 paper for the scientific journal "Proceedings of the United States National Museum", based on two specimens collected in Batangas Bay, south of Luzon in the Philippines. One of these, a 15-cm-long adult male, was designated the type specimen. Smith and Radcliffe coined the new genus "Squaliolus" for this shark, and gave it the specific epithet "laticaudus", from the Latin "latus" meaning "broad" or "wide", and "cauda" meaning "tail".
Spined pygmy shark | Taxonomy and phylogeny
The species was first described in 1994 by paleontologists Kiyoharu Hirota and Lawrence Barnes. Observing the teeth which were present in both jaws and coated in enamel, they had placed it into the genus "Scaldicetus" which was described in 1867 as having similar characteristics. However, a 1995 study stated that since "Scaldicetus" is described only from tooth remains and is likely a wastebasket taxon, new species should not be assigned to the genus. Therefore, the study authored by paleontologists Kimura Toshiyuki, Hasegawa Yoshikazu, and Barnes Lawrence placed it into the newly erected genus "Brygmophyseter". A 2006 study by geologists Giovanni Bianucci and Walter Landini placed the whale into the genus "Naganocetus" which they had created, and concluded that it was most closely related to "Zygophyseter", which they had for the first time described in the same study.
Brygmophyseter | Phylogeny
In evolutionary terms, the frilled shark is an animal species of recent occurrence in the natural history of the Earth; the earliest discoveries of the fossilized teeth of the "Chlamydoselachus anguineus" species of shark date to the early Pleistocene epoch (2.58–11.70 mya). In 2009, marine biologists identified, described, and classified the "Chlamydoselachus africana" (southern African frilled shark) of the Atlantic waters of southern Angola and of southern Namibia as a species of frilled shark different from the "Chlamydoselachus anguineus" identified in 1884.
Frilled shark | Taxonomy and phylogeny
The Australian blacktip shark was described by Australian ichthyologist Gilbert Percy Whitley in a 1950 issue of the scientific journal "Western Australian Naturalist". He named it "Galeolamna pleurotaenia tilstoni" in honor of Richard Tilston, assistant surgeon at Port Essington, Northern Territory. The type specimen is a long female caught from Van Cloon Reef in Joseph Bonaparte Gulf. Later authors have regarded "Galeolamna" as a synonym of the genus "Carcharhinus". This shark may also be referred to as blacktip whaler, Tilston's whaler shark, and Whitley's blacktip shark. After Whitley's initial description, "C. tilstoni" was generally regarded as synonymous with "C. limbatus", the common blacktip shark.
Australian blacktip shark | Taxonomy and phylogeny
A distinctive dark blotch at the tip of the snout is most obvious in young sharks. The tips of the second dorsal fin, upper caudal fin lobe, and sometimes the lower caudal fin lobe, are dark. Blacknose sharks are typically long and in weight. The maximum length and weight on record is and , respectively.
Blacknose shark | Description
The taxonomic history of the Family Stethacanthidae has been rather complicated because the findings of complete skeletons are very unusual, and as result early workers such as St. John & Worthen, and Newberry were unable to recognise the association of the spine, dentition teeth, and dermal denticles of these sharks. The genus "Stethacanthus" was established by Newberry (1889) for a series of large thin walled, cartilage-cored spines encountered in Mississippian (Carboniferous Period) rocks of the mid-continental United States. Decomposition of the internal cartilage and compression during burial resulted in distortion of the spines, leading Newberry to misinterpret them, he believed that the spines belonged to pectoral and pelvic fins of a new species of shark.
Stethacanthidae | Introduction
The pyjama shark was originally described as "Squalus africanus" by German naturalist Johann Friedrich Gmelin in 1789, in the thirteenth edition of "Systema Naturae". He did not designate a type specimen. In 1837, Scottish physician and zoologist Andrew Smith created the new genus "Poroderma" for this species and the related leopard catshark ("P. pantherinum", at the time believed to be multiple species). In 1908, the pyjama shark was made the type species of the genus by American zoologist Henry Weed Fowler.
Pyjama shark | Taxonomy
"Sphenacanthus" was discovered in Carboniferous terrains of Scotland (Visén Oil Shale Groups), in the United Kingdom, in ancient fresh water systems, a habitat that also is known in the Paraná Basin in Brazil (Rio do Rasto Formation). Another findings, like those of the Puertollano Bason in Spain suggests that also it lived in zones of marine influence, in brackish waters. It shared its environment with other primitive sharks, including to "Xenacanthus" of one meter in length and the similar species, "Tristychius arcuatus". It is possible that "Sphenacanthus" may have preyed on its smaller relatives.
Sphenacanthus | Paleobiology
The hindermost of the five gill slits is above the origin of the pectoral fins, and no spiracles occur. The first dorsal fin is long, narrow, and curved (falcate) and has a short rear tip. It is either pointed or narrowly rounded at the apex and its origin is directly over the free posterior end of the pectoral fins. The second dorsal fin is relatively large. It also has a short rear tip and its origin is slightly behind the origin of the anal fin. The pectoral fins are falcate, long and narrow, and taper to a blunt point. No fleshy keel exists along the sides of the caudal peduncle.
Blackspot shark | Description
It was first discovered in 1993 from coastal isolates of coral in the Republic of Palau in the west Pacific Ocean and announced in 1996. Despite the claim in the 1996 "Nature" paper that its formal description was to be published shortly thereafter, a tentative partial description was presented in 2003 due to phylogenetic issues (deep branching cyanobacterium).
Acaryochloris marina | Description
It was first described by Jen Veron and C. C. Wallace in 1984 as "Acropora kirstyae".
Acropora kirstyae | Taxonomy
The blacknose shark has a slender, streamlined body with a long, rounded snout and large eyes. A well-developed flap of skin occurs in front of each nostril, defining the inflow and outflow openings. Twelve to 13 and 11 to 12 tooth rows occur on either side of the upper and lower jaws, respectively, with one or two teeth at the symphysis (middle). The teeth are triangular and oblique, with serrated edges; the upper teeth are stouter than the lower teeth. The five pairs of gill slits are short, measuring less a third the length of the first dorsal fin base.
Blacknose shark | Description
The first discovered "Pontohedyle" species is well described and abundant "Pontohedyle milaschewitchii" from the Black Sea and Mediterranean. The second discovered species is poorly known Western Pacific "Pontohedyle verrucosa" from the Solomon Islands. In absence of distinguishing morphological characters Jörger et al. (2007) synonymized the tropical Western Atlantic "Pontohedyle brasilensis" with its temperate congener "Pontohedyle milaschewitchii". Subsequently (2012) authors tested molecular markers to detect possible cryptic species and they reestablished "Pontohedyle brasilensis" as a valid taxon and they uncovered at least nine (undescribed) candidate species. There are at least nine candidate species plus three confirmed valid species:
Pontohedyle | Species
Shark expert Stewart Springer described the bignose shark as "Eulamia altima" in a 1950 issue of the scientific journal "American Museum Novitates". Later authors have regarded the genus "Eulamia" as a synonym of "Carcharhinus". The specific epithet "altimus" is derived from the Latin "altus" ("deep"), and refers to the shark's deepwater habits. The type specimen is an immature female long, caught off Cosgrove Reef in the Florida Keys on April 2, 1947. An alternate common name for this species is Knopp's shark, originally used by Florida fishery workers since before the species was described. Phylogenetic studies published by Jack Garrick in 1982 and Leonard Compagno in 1988, based on morphology, placed the bignose shark in the ""obscurus" group" of "Carcharhinus", centered on the dusky shark ("C.
Bignose shark | Taxonomy and phylogeny
This species was first formally described in 1828 by Charles Gaudichaud-Beaupré from a specimen collected in Shark Bay during the Bougainville expedition in the ships "l'Uranie" and "la Physicienne" from 1817 to 1820. The specific epithet ("cuneata") is a Latin word meaning "wedge-shaped".
Quoya cuneata | Taxonomy and naming
"Phyllolepis" was the first genus to be recognized in the order Phyllolepidae until 1984. "Phyllolepis concentrica" was the first species discovered of the genus, by Louis Agassiz in 1844 at Clashbennie, Scotland. This specimen caused Woodward to incorrectly classify them as a distinct group belonging to the jawless fishes in 1915, along with "Drepanaspidae". Sensiö continued, with several publications in the 1930s, to show that phyllolepids had jaws, and belonged with placoderms. He also proclaimed them part of Phyllolepida, based on his studies of "P. orvini, P. soederberghi," and "P. neilseni". From the 1930s to 50s, there were several isolated dermal plates of phyllolepids found in Australia, attributed by Hills to be "Phyllolepis" but specific species left undefined.
Phyllolepis | History of categorization
The Cretaceous shark genus "Cretalamna hattini" was named for him.
Donald E. Hattin | Introduction
The basking shark is the only extant member of the family Cetorhinidae, part of the mackerel shark order Lamniformes. Johan Ernst Gunnerus first described the species as "Cetorhinus maximus", from a specimen found in Norway, naming it. The genus name "Cetorhinus" comes from the Greek "ketos", meaning "marine monster" or "whale", and "rhinos", meaning "nose". The species name "maximus" is from Latin and means "greatest". Following its initial description, more attempts at naming included: "Squalus isodus", in 1819 by Italian Zoologist Saverio Macri (1754–1848); "Squalus elephas", by Charles Alexandre Lesueur in 1822; "Squalus rashleighanus", by Jonathan Couch in 1838; "Squalus cetaceus", by Laurens Theodorus Gronovius in 1854; "Cetorhinus blainvillei" by the Portuguese biologist Felix Antonio De Brio Capello (1828–1879) in 1869; "Selachus pennantii", by Charles John Cornish in 1885; "Cetorhinus maximus infanuncula", by the Dutch Zoologists Antonius Boudewijn Deinse (1885–1965) and Marcus Jan Adriani (1929–1995) in 1953; and "Cetorhinus maximus normani", by Siccardi in 1961.
Basking shark | Taxonomy
Based on morphology, Leonard Compagno in 1988 tentatively grouped the smoothtooth blacktip shark with the spinner shark ("C. brevipinna"), the blacktip shark ("C. limbatus"), the graceful shark ("C. amblyrhynchoides"), and the finetooth shark ("C. isodon"). Using molecular phylogenetic techniques on mitochondrial DNA sequences, Alec Moore and colleagues reported in 2011 that this species is closely related to the graceful shark, the blacktip shark, and the Australian blacktip shark ("C. tilstoni").
Smoothtooth blacktip shark | Taxonomy and phylogeny
This species is distinguished from related Black Sea basin inhabitants by the following: 75-95% of its length is between its origin and anus; ctenoid scales completely cover the predorsal area and nape; pelvic disc fraenum with angular lobes, Distinguishing characteristics include a fraenum with length 1/6-1/2 of its width at base, midlateral series scales 68-72 +3-4, a snout length 1.5-2.0 times its eye diameter, that its first branched ray of second dorsal is about as long as penultimate ray and that the posterior part of first dorsal is without a black spot.
Ponticola kessleri | Characteristics
Fossilized teeth from the copper shark have been recovered from the Pungo River in North Carolina, dating to the Miocene (23–5.3 Ma), from Tuscany, dating to the Pliocene (5.3–2.6 Ma), and from Costa Mesa in California, dating to the Late Pleistocene (126,000–12,000 years ago).
Copper shark | Phylogeny and evolution
The first specimen of "M. parini" was found off the coast of Chile in the Nazca Submarine Ridge. This specimen was an adolescent female with a total length of , taken at a depth of , in 1979. This initially suggested that the species was distributed throughout the Pacific Ocean. In February 2010, a similar specimen with a total length of was caught off the coast of Louisiana, in the Gulf of Mexico. This second specimen was determined to be a new species which was described and named as "M. mississippiensis". It is now believed that the genus "Mollisquama" is more widely dispersed than what was previously hypothesized.
Pocket shark | Distribution and habitat
Ward & Bonavi (2001) reexamined the teeth of "I. hastalis" and noted a strong morphological similarity between it and the extant great white shark. The study concluded that "I. hastalis" is a direct ancestor of the great white and is more related to it than other makos. This moved the species into the genus "Cosmopolitodus", which was a move that was first proposed by Glikman (1964) but was long rejected beforehand. Later discoveries supports Ward & Bonavi's conclusion of its ancestry to the great white. An analysis of a newly discovered "Carcharodon hubbelli" by Ehret et al. (2012) further cemented the theory of "C.
Cosmopolitodus | Taxonomic history
The body is robustly built, with large, broad, paddle-like pectoral fins that originate under the fifth gill slit. The first dorsal fin originates over the posterior half of the pectoral fin bases. The second dorsal fin is about half as tall as the first and located over or slightly ahead of the anal fin. The anal fin is smaller than the second dorsal fin and has a deep notch in the rear margin. The caudal fin has a well-developed lower lobe and is preceded by a crescent-shaped notch on the upper side of the caudal peduncle. The coloration is a plain gray above, sometimes with a brownish or yellowish cast, and lighter below.
Daggernose shark | Description
Listracanthus is a genus of extinct chondrichthyan with uncertain affinities. Species of "Listracanthus" are known primarily from their tremendous, feather-like denticles, which range up to four inches in length. The denticles had a large main spine, from which secondary spines emanate from the sides, like the barbs of a feather or a comb. "Listracanthus" first appeared in late Carboniferous strata in North America, and eventually disappear from the fossil record some time during the Early Triassic. The appearance of these sharks are largely unknown. However, author and illustrator Ray Troll mentions in his book, "Sharkabet", about how paleontologist Rainer Zangerl once discovered a large shale slab containing a long, eel-like fish covered in long, spine-like denticles characteristic of the genus, only to have it dry out and crumble into dust.
Listracanthus | Introduction
Eoptolamna is an extinct genus of mackerel shark from the Cretaceous Period. It is a monotypic genus, currently holding only "E. eccentrolopha" described from the Barremian and Albian Artoles Formation of Spain.
Eoptolamna | Introduction
The sharpnose sevengill shark is uncommon, but widely distributed in the tropical and temperate regions of all oceans except for the northeastern Pacific Ocean. It is found from North Carolina to Cuba, including the northern Gulf of Mexico, and from Venezuela to Argentina in the western Atlantic. In the eastern Atlantic, it occurs from Morocco to Namibia, including the Mediterranean Sea. It is reported from the Indian Ocean off southwestern India, Aldabra Island, southern Mozambique, and South Africa. In the Pacific Ocean, it is known from Japan to China, Indonesia, Australia, New Zealand, and northern Chile. This is a demersal to semipelagic species usually captured at a depth of , but is occasionally found close to the surface (though these reports may represent misidentifications) or down to .
Sharpnose sevengill shark | Distribution and habitat
The Swiss naturalist Louis Agassiz, first identified this shark as a species of genus "Carcharodon" in 1835. In 1964, shark expert, L. S. Glikman recognized the transition of "Otodus obliquus" to "C. auriculatus" and moved "C. angustidens" to genus "Otodus". (See "external links" below) However, in 1987, shark expert H. Cappetta recognized the "C. auriculatus" - "C. megalodon" lineage and placed all related megatooth sharks along with this species in the genus "Carcharocles". The complete "Otodus obliquus" to "C. megalodon" transition then became clear and has since gained the acceptance of many other experts with the passage of time. Within the "Carcharocles" lineage, "C.
Otodus angustidens | Taxonomy
Crassitarsae was first proposed as a taxon by Robert J. Raven in 1985, based on a morphological cladistic analysis of Mygalomorphae. In Raven's analysis one shared character is the presence of some scopulae on the tarsi. (The Latin adjective means 'thick', 'fat'.) The third claw is usually reduced in size, and the anterior lateral spinnerets are absent. Another morphological cladistic analysis, by Pablo Goloboff in 1993, supported the Crassitarsae, although with a slightly different circumscription. Goloboff's Crassitarsae was regarded as a viable taxonomic hypothesis in a 2006 molecular phylogenetic analysis, although not explicitly supported, and was recovered (again with a different circumscription) in a 2012 study of Mygalomorphae.
Crassitarsae | Taxonomy
It was first described in 2009 by Peter Heenan, Peter de Lange and J. Keeling.
Alternanthera nahui | Taxonomy
This interpretation was corroborated by Lavery (1992), based on allozyme data.
Silvertip shark | Taxonomy and phylogeny
Subsequent authors moved the blacktip reef shark to the genus "Carcharhinus"; in 1965 the International Commission on Zoological Nomenclature designated it as the type species for the genus. In some earlier literature, the scientific name of this shark was mistakenly given as "C. spallanzani", now recognized as a synonym of the spottail shark ("C. sorrah"). Other common names for this species include blackfin reef shark, black-finned shark, blacktip shark, reef blacktip shark, and guliman.
Blacktip reef shark | Taxonomy
The origin of the first dorsal fin lies over or slightly forward of the free rear tips of the pectoral fins, and that of the second dorsal fin lies over or slightly forward of the anal fin. The pectoral fins are long and narrow, tapering to a point. The dermal denticles are closely spaced and overlapping, each with five (sometimes seven in large individuals) horizontal low ridges leading to marginal teeth.
Caribbean reef shark | Description
dussumieri") and the blackspot shark ("C. sealei"). Shane Lavery, in a 1992 study based on allozymes, reported that this species was close to the nervous shark ("C. cautus") and the blacktip reef shark ("C. melanopterus"). Ximena Vélez-Zuazoa and Ingi Agnarsson, in a 2011 study based on nuclear and mitochondrial genes, found it to be the basal member of a clade also containing the graceful shark ("C. amblyrhynchoides"), the blacktip shark ("C. limbatus"), and the Australian blacktip shark ("C. tilstoni").
Creek whaler | Taxonomy and phylogeny
The population was named in a description published by Edgar Ravenswood Waite in 1896, the holotype was obtained at Alice Springs; the author allied the new species to the genus "Mus". Another description was provided in 1910 by the mammalogist Oldfield Thomas, a new species named as "Pseudomys" ("Thetomys") "praeconis". Thomas described a specimen that was obtained at Shark Bay, where the collector Guy C. Shortridge found the dry skull of a female laying on the ground on Bernier Island at the Peron Peninsula; Shortridge reported that he thought the species was locally extinct. Another specimen held at the British Museum, an old female obtained by F.
Djoongari | Taxonomy
A set of poorly described, Eocene (56–34 Mya) teeth resembling those of this species are known from Egypt. Initial efforts to resolve the evolutionary relationships of the silky shark were inconclusive; based on morphology, Jack Garrick in 1982 suggested the blackspot shark ("C. sealei") as its closest relative. In 1988, Leonard Compagno assigned it phenetically to an informal "transitional group" also containing the blacknose shark ("C. acronotus"), the blacktip reef shark ("C. melanopterus"), the nervous shark ("C. cautus"), the copper shark ("C. brachyurus"), and the night shark ("C. signatus"). More recently, Gavin Naylor's 1992 phylogenetic analysis, based on allozyme sequence data, found that the silky shark is part of a group containing large sharks with a ridge between the dorsal fins.
Silky shark | Phylogeny and evolution