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 Act Amendments of 1978 Endangered Species Act Amendments of 1978 The Endangered Species Act (ESA) was first passed in 1973 and forms the basis of biodiversity and endangered species protection in the United States. The original purpose of the Endangered Species Act of 1973 was to prevent species endangerment and extinction due to the human impact on natural ecosystems. The three most powerful sections of the ESA are Sections 4,7 and 9. Section 4 allows the Secretaries of Interior and Commerce to list species as threatened or endangered based on best available data. Section 7 requires federal agencies to consult with Fish and Wildlife