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Whippomorpha or Cetancodonta is a group of artiodactyls that contains all living cetaceans (whales, dolphins, and porpoises) and the hippopotamids. [1] All whippomorphs are descendants of the last common ancestor of Hippopotamus amphibius and Tursiops truncatus.
The earliest known ancestor of arctic whales is Denebola brachycephala from the late Miocene around 9–10 million years ago. [55] A single fossil from Baja California indicates the family once inhabited warmer waters. [27] [56] [57] Acrophyseter skull. Ancient sperm whales differ from modern sperm whales in tooth count and the shape of the ...
The most recent theory of the origins of Hippopotamidae suggests hippos and whales shared a common semiaquatic ancestor that branched off from other artiodactyls around [ 13 ] [ 15 ] This hypothesised ancestral group likely split into two branches again around 54 million years ago .
Since the fossil record suggests that the morphologically distinct hippo lineage dates back only about 15 million years, Cetacea and hippos apparently diverged from a common ancestor that was morphologically distinct from either. [79] [80] [81] The most striking common feature is the talus, a bone in the upper ankle.
The mesonychians were long considered ancestors of whales. Modern cetaceans are highly adapted sea creatures which, morphologically, have little in common with land mammals; they are similar to other marine mammals, such as seals and sea cows, due to convergent evolution. However, they evolved from originally terrestrial mammals.
This led to some theories that the last common ancestors of hippos and whales was a semiaquatic mammal, but in a 2015 genomic study that compared the genes responsible in aquatic adaptations within Whippomorpha found it to be the result of convergent evolution, as opposed to shared ancestry. This resolves the issue of how hippos and whales ...
Articles relating to the Whippomorpha, a group of animals that contains all living cetaceans (whales, dolphins, etc.) and hippopotamuses, as well as their extinct relatives, i.e. Entelodonts, Andrewsarchus All Whippomorphs are descendants of the last common ancestor of Hippopotamus amphibius and Tursiops truncatus.
The pygmy right whale shares several characteristics with the right whales, with the exception of having a dorsal fin. Also, pygmy right whales' heads are no more than one quarter the size of their bodies, whereas the right whales' heads are about one-third the size of their bodies. [11] The pygmy right whale is the only extant member of its ...