Search results
Results from the WOW.Com Content Network
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.
In cetaceans, evolution in the water has caused changes to the head that have modified brain shape such that the brain folds around the insula and expands more laterally than in terrestrial mammals. As a result, the cetacean prefrontal cortex (compared to that in humans) rather than frontal is laterally positioned.
Portal:Cetaceans/Did you know/12 . Pakicetus was a prehistoric cetacean....cetaceans have evolved from land mammals. Evidence of this is seen in the vestigial hip bones, as well in the pentadactyl ("five-fingered") dorsal flippers/fins....Herman Melville included an objective study of the properties of whales in Moby-Dick.
They greatly affected cetacean evolution , because they spread across Earth's oceans. [7] They had long snouts, large eyes, and a nasal opening located farther up the head than in earlier archaeocetes — suggesting they could breathe with the head held horizontally, similar to modern cetaceans — a first step towards a blowhole.
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 traditional theory of cetacean evolution was that cetaceans were related to the mesonychian. These animals had unusual triangular teeth very similar to those of primitive cetaceans. This is why scientists long believed that cetaceans evolved from a form of mesonychian.
(from Evolution of cetaceans) Sei whale illustration. A phylogenetic tree showing the relationships among cetacean families. (from Evolution of cetaceans) Antarctic ...
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 ...