Marine mammal Marine mammal Marine mammals are aquatic mammals that rely on the ocean and other marine ecosystems for their existence. They include animals such as seals, whales, manatees, sea otters and polar bears. They do not represent a distinct taxon or systematic grouping, but rather have a polyphyletic relation due to convergent evolution, as in they do not have an immediate common ancestor. They are also unified by their reliance on the marine environment for feeding. Marine mammal adaptation to an aquatic lifestyle varies considerably between species. Both cetaceans and sirenians are fully aquatic and therefore are obligate water dwellers. Seals
Saint Bathans mammal adzebills are represented by unnamed species, as are various representatives of groups such as waterfowl, flamingos, rails, herons, strigopoidean parrots and even an early kiwi, "Proapteryx". However, unlike modern New Zealand it also had a varied herpetofauna: besides an early tuatara, the Saint Bathans fauna also includes meiolaniid and pleurodire turtles and possiblymekosuchine crocodiles and snakes. Besides the Saint Bathans mammal, this fauna also includes mystacine bats, a group still present in modern New Zealand. Like the modern species, these were probably terrestrial foragers, the same general ecological niche proposed for the Saint Bathans mammal. Other bats, including a vesper