Search results
Results from the WOW.Com Content Network
[1] The evolution of cetaceans is thought to have begun in the Indian subcontinent from even-toed ungulates (Artiodactyla) 50 million years ago (mya) and to have proceeded over a period of at least 15 million years. [2] Cetaceans are fully aquatic mammals belonging to the order Artiodactyla and branched off from other artiodactyls around 50 mya.
Other aquatic mammals, such as the Indian rhinoceros, were targets for sport hunting and had a sharp population decline in the 1900s. After it was made illegal, many aquatic mammals became subject to poaching. Other than hunting, aquatic mammals can be killed as bycatch from fisheries, where they become entangled in fixed netting and drown or ...
Marine mammal adaptation to an aquatic lifestyle varies considerably between species. Both cetaceans and sirenians are fully aquatic and therefore are obligate water dwellers. Pinnipeds are semiaquatic; they spend the majority of their time in the water but need to return to land for important activities such as mating, breeding and molting.
Cetaceans are descended from land-dwelling hoofed mammals, and the now extinct archaeocetes represent the several transitional phases from terrestrial to completely aquatic. [1] Historically, cetaceans were thought to have descended from the wolf-like mesonychians , but cladistic analyses confirm their placement with even-toed ungulates in the ...
The name Whippomorpha is a combination of English (wh[ale] + hippo[potamus]) and Greek (μορφή, morphē = form). [2]Some attempts have been made to rename the suborder Cetancodonta, due to the misleading utilization of the suffix -morpha for a crown group, [6] as well as the risk of confusion with the clade Hippomorpha (which consists of equid perissodactyls); [7] however Whippomorpha ...
Cetacea (/ s ɪ ˈ t eɪ ʃ ə /; from Latin cetus 'whale', from Ancient Greek κῆτος () 'huge fish, sea monster') [3] is an infraorder of aquatic mammals belonging to the order Artiodactyla that includes whales, dolphins and porpoises.
Artiodactyla is an order of placental mammals composed of even-toed ungulates – hooved animals which bear weight equally on two of their five toes with the other toes either present, absent, vestigial, or pointing posteriorly – as well as their descendants, the aquatic cetaceans. Members of this order are called artiodactyls.
Marine mammals comprise over 130 living and recently extinct species in three taxonomic orders. The Society for Marine Mammalogy, an international scientific society, maintains a list of valid species and subspecies, most recently updated in October 2015. [1] This list follows the Society's taxonomy regarding and subspecies.