In biological classification , a subfamily ( Latin : subfamilia , plural subfamiliae ) is an auxiliary (intermediate) taxonomic rank , next below family but more inclusive than genus . Standard nomenclature rules end botanical subfamily names with "-oideae", and zoological subfamily names with "-inae".
19-479: The Tylosaurinae are a subfamily of mosasaurs , a diverse group of Late Cretaceous marine squamates . Members of the subfamily are informally and collectively known as "tylosaurines" and have been recovered from every continent except for South America . The subfamily includes the genera Tylosaurus , Taniwhasaurus , and Kaikaifilu , although some scientists argue that only Tylosaurus and Taniwhasaurus should be included. Tylosaurines first appeared in
38-518: A "battering ram" snout is not supported by fossil evidence. Stomach contents from a tylosaur recovered in South Dakota included remains of another mosasaur, a bony fish , the large, flightless seabird Hesperornis , and possibly a shark , indicating that tylosaurs were generalists. Another specimen collected by Charles Sternberg included the bones of a small plesiosaur (see also ). Lingham-Soliar suggested that tylosaurines were not among
57-445: A period lasting approximately twenty million years. The etymology of this group derives from the genus Tylosaurus ( Greek tylos = "knob" + Greek sauros = "lizard"). In general, tylosaurines were large-bodied marine lizards armed with sturdy, conical teeth and an elongated premaxilla and extensions of the dentaries that do not bear teeth to the very end such as is found in other genera of mosasaurs. Cope's original concept of
76-678: A single foramen . No canal in basioccipital or basispehnoid for basilar artery. Suprastapedial process of quadrate moderately large, distally pointed. Dorsal edge of surangular rounded and longitudinally horizontal...Twenty nine presacral vertebrae present. Length of presacral series less than that of postsacral series in Tylosaurus , neural spines of posterior caudal vertebrae at most only slightly elongated, do not form an appreciable fin. Haemal arches unfused to caudal centra. Appendicular elements lack smoothly finished articular surfaces." Tylosaurinae Subfamily Detarioideae
95-683: Is an example of a botanical subfamily. Detarioideae is a subdivision of the family Fabaceae (legumes), containing 84 genera. Stevardiinae is an example of a zoological subfamily. Stevardiinae is a large subdivision of the family Characidae , a diverse clade of freshwater fish . This biology article is a stub . You can help Misplaced Pages by expanding it . Characidae Aphyocharacinae Aphyoditeinae Bryconinae Characinae Cheirodontinae Gymnocharacinae Heterocharacinae Iguanodectinae Pristellinae Rhoadsiinae Salmininae Stethaprioninae Stevardiinae Tetragonopterinae and see text Characidae ,
114-655: The Coniacian and gave rise to some of the largest mosasaurs within the genera Tylosaurus and Hainosaurus which came to dominate as apex predators in marine ecosystems throughout the Santonian and Campanian , but appear to have been largely replaced by large mosasaurines , such as Mosasaurus , by the end of the Maastrichtian . Nevertheless, the subfamily survived to the end of the Cretaceous, covering
133-639: The Ostariophysi – fishes possessing a Weberian apparatus – has yet to be settled conclusively. Until that phylogeny is settled, the opportunity for yet more upheavals within the taxonomy of the characoid fishes is considerable. The subfamilies and tribes currently recognized by most if not all authors, and their respective genera, are: Subfamily Spintherobolus clade Subfamily Stethaprioninae Subfamily Stevardiinae Subfamily Characinae Subfamily Pristellinae The Chalceidae , Iguanodectidae , Bryconidae and Heterocharacinae are
152-491: The Tetragonopterinae , which had become something of a " wastebin taxon " – are poorly known, a comprehensive phylogenetic study for the entire family is needed. The genera Hyphessobrycon , Astyanax , Hemigrammus , Moenkhausia , and Bryconamericus include the largest number of currently recognized species among characid fishes that are in need of revision; Astyanax and Hyphessobrycon in
171-421: The blind cave tetra , for example, inhabits flooded caves . Spintherobolus clade Stethaprioninae Stevardiinae Aphyocharacini Cheirodontini Compsurini Exodontini Tetragonopterini Characini This family has undergone a large amount of systematic and taxonomic change. More recent revision has moved many former members of the family into their own related but distinct families –
190-426: The characids or characins , is a family of freshwater subtropical and tropical fish belonging to the order Characiformes . The name "characins" is a historical one, but scientists today tend to prefer "characids" to reflect their status as a, by and large, monophyletic group (at family rank). To arrive there, this family has undergone much systematic and taxonomic change. Among those fishes remaining in
209-599: The pencilfishes of the genus Nannostomus are a typical example, having now been moved into the Lebiasinidae , the assorted predatory species belonging to Hoplias and Hoplerythrinus have now been moved into the Erythrinidae , and the sabre-toothed fishes of the genus Hydrolycus have been moved into the Cynodontidae . The former subfamily Alestiinae was promoted to family level ( Alestiidae ) and
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#1732800843000228-475: The Characidae currently are the tetras , comprising the very similar genera Hemigrammus and Hyphessobrycon , as well as a few related forms, such as the cave and neon tetras. Fish of this family are important as food in several regions, and also constitute a large percentage of captive freshwater aquarium fish species. These fish vary in length; many are less than 3 cm (1.2 in). One of
247-482: The Characidae, but various revisions place them in their own related family, the Serrasalmidae . This reassignment has yet to enjoy universal acceptance, but is gaining in popularity among taxonomists working with these fishes. Given the current state of flux of the Characidae, a number of other changes will doubtless take place, reassigning once-familiar species to other families. Indeed, the entire phylogeny of
266-420: The fastest swimming nor the strongest mosasaurids. However, they are lightly built, having greatly reduced the weight of their bodies and possessing relatively small pectoral and pelvic girdles, fore- and hindlimbs. Their bone is highly cancellous and may have been impregnated with fat cells during life, adding buoyancy. These traits suggest that tylosaurs may have been ambush predators . Tylosaurs were among
285-473: The largest mosasaurs, with some species of Tylosaurus and Hainosaurus reaching lengths of 9-12+ meters, making them among the largest of all marine reptiles. Russell (1967, pp. 170 ) defined the Tylosaurinae as follows: "Large rostrum present anterior to premaxillary teeth. Twelve or more teeth in dentary and maxilla . Cranial nerves X, XI, and XII leave lateral wall of opisthotic through
304-494: The most recent clades to be removed in order to maintain a monophyletic Characidae. Subfamily Iguanodectinae moved to Iguanodectidae Subfamily Heterocharacinae moved to Acestrorhynchidae Subfamily Bryconinae moved to Bryconidae Subfamily Salmininae moved to Bryconidae Genera incertae sedis A large number of taxa in this family are incertae sedis . The relationships of many fish in this family – in particular species traditionally placed in
323-530: The smallest species, Hyphessobrycon roseus , grows to a maximum length of 1.9 cm. These fish inhabit a wide range and variety of habitats. New World fishes, they originate in the Americas , ranging from southwestern Texas and México through most of Central and South America , including such major waterways as the Amazon and Orinoco Rivers. Many of these fish come from rivers and tributaries, while
342-595: The subfamilies Crenuchinae and Characidiinae were moved to the family Crenuchidae . Other fish families that were formerly classified as members of the Characidae, but which were moved into separate families of their own during recent taxonomic revisions (after 1994) include Acestrorhynchidae , Anostomidae , Chilodontidae , Citharinidae , Ctenoluciidae , Curimatidae , Distichodontidae , Gasteropelecidae , Hemiodontidae , Hepsetidae , Parodontidae , Prochilodontidae , Serrasalmidae , and Triportheidae . The larger piranhas were originally classified as belonging to
361-405: The usual delimitation are among the largest genera in this family. These genera were originally proposed between 1854 and 1908 and are still more or less defined as by Carl H. Eigenmann in 1917, though diverse species have been added to each genus since that time. The anatomical diversity within each genus, the fact that each of these generic groups at the present time cannot be well-defined, and
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