South Asian river dolphin display the variances needed to support their classification as separate species. Thus, at present, a single species with two subspecies is recognized in the genus "Platanista", "P. g. gangetica" (Ganges river dolphin) and "P. g. minor" (Indus river dolphin). An assessment of divergence rates in mitochondrial DNA of the two subspecies indicates that they diverged from a common ancestor around 550,000 years ago. This ancestor is thought to have been a marine Platanistid inhabiting the epi-continental seas in South Asia during the sea level rises in the middle Miocene. The earliest fossil identified as belonging to the species is only
Endangered Species Act of 1973 prior to being listed), ten due to changes in taxonomic classification practices, six due to discovery of new populations, one due to an error in the listing rule, and one due to an amendment to the Endangered Species Act specifically requiring the species delisting. Twenty-five others have been down listed from "endangered" to "threatened" status. Some have argued that the recovery of DDT-threatened species such as the bald eagle, brown pelican and peregrine falcon should be attributed to the 1972 ban on DDT by the EPA. rather than the Endangered Species Act, however, the listing of these species as endangered