Squalodontidae closely related to the South Asian river dolphin ("Platanista gangetica"). The genus "Squalodon" was named by French naturalist Jean-Pierre Sylvestre de Grateloup in 1840 based on a jaw fragment he thought belonged to a reptile. Fossils discovered later, nevertheless, showed that this was a toothed whale. In extant odontocetes, however, the dentition is atavistic with all teeth reduced to simple, undifferentiated conical shapes. In squalodonts the teeth resemble those of the archaic whales, Archaeoceti, with conical incisors anteriorly and low-crowned, serrated teeth posteriorly. Squalodontidae Squalodontidae or the shark-toothed dolphins is an extinct family of large toothed whales who had long
Endangered species recovery plan common goal. An endangered species is a species which is likely to become extinct. The U.S. Fish and Wildlife Service has 17 categories of species status. These categories are used in the documents produced for the U.S. Endangered species act. The categories include: The IUCN also has categories that it uses to classify species, which are more widely used in conservation. These are: The recovery plan must contain at least: A recovery plan often contains the following sections: When recovery plans are carried out well, they do not simply act as stop gaps to prevent extinction, but can restore species