Arktocara ("Platanista gangetica") which inhabits the tropics, making it its closest living relative. Allodelphinidae also included the genera "Allodelphis", "Goedertius", "Ninjadelphis", and "Zarhinocetus". Its discovery further reinforces the theory that the Platanistoidea river dolphins originated in the oceans. Of the characteristics it shared with other platanistoids was a cylindrical projection of the periotic bone in the ear, deeply grooved rostral sutures on the beak, the widening of the cranium, a depression on the roof of the orbit in the eye socket, a smaller exposed palatine bone in the roof of the mouth, an elongated and convex spine in the tympanic bulla
Endangered Species Act of 1973 was a substantial cause of Congress instituting the ban and many non-DDT oriented actions were taken on their behalf under the Endangered Species Act (i.e. captive breeding, habitat protection, and protection from disturbance). As of October 28, 2012, there are 2,052 total (foreign and domestic) species on the threatened and endangered lists. However, many species have become extinct while on the candidate list or otherwise under consideration for listing. Species which increased in population size since being placed on the endangered list include: Opponents of the Endangered Species Act argue that with over 2,000 endangered species listed, and only 28