Cetacean stranding, commonly known as beaching, is a phenomenon in which whales and dolphins strand themselves on land, usually on a beach. Beached whales often die due to dehydration, collapsing under their own weight, or drowning when high tide covers the blowhole. Cetacean stranding has occurred since before recorded history.
A mass stranding of pilot whales on the shore of Cape Cod, 1902
Beached false killer whales at Flinders Bay, Western Australia, 1986
Three Beached Whales, a 1577 engraving by the Flemish artist Jan Wierix, depicts stranded sperm whales. Note the incorrectly recorded "nostril" and plausible extruded penis.
"The Whale beached between Scheveningen and Katwijk, with elegant sightseers", by Esaias van de Velde, c. 1617
Whales are a widely distributed and diverse group of fully aquatic placental marine mammals. As an informal and colloquial grouping, they correspond to large members of the infraorder Cetacea, i.e. all cetaceans apart from dolphins and porpoises. Dolphins and porpoises may be considered whales from a formal, cladistic perspective. Whales, dolphins and porpoises belong to the order Cetartiodactyla, which consists of even-toed ungulates. Their closest non-cetacean living relatives are the hippopotamuses, from which they and other cetaceans diverged about 54 million years ago. The two parvorders of whales, baleen whales (Mysticeti) and toothed whales (Odontoceti), are thought to have had their last common ancestor around 34 million years ago. Mysticetes include four extant (living) families: Balaenopteridae, Balaenidae, Cetotheriidae, and Eschrichtiidae. Odontocetes include the Monodontidae, Physeteridae, Kogiidae, and Ziphiidae, as well as the six families of dolphins and porpoises which are not considered whales in the informal sense.
Whale
Basilosaurus skeleton
Skeleton of a bowhead whale; notice the vestigial pelvis. Richard Lydekker, 1894
Sperm whale skeleton. Richard Lydekker, 1894.