|Gray , 1821
The dolphin-like (Delphinoidea) form a superfamily within the order of the whales (Cetacea). They summarize the three families of the gudgeon whales (Monodontidae), the porpoises (Phocoenidae) and the dolphins (Delphinidae).
Despite considerable differences in body shape, these three groups show similarities in the construction of the skull and - compared to other whales - have a relatively unspecialized body structure . The close relationship of these three groups has also been confirmed by molecular genetic studies. It turned out that the gudgeon and porpoise are sister taxa and are more closely related to each other than to the dolphins. The monophyly of each of the three families could also be confirmed.
The dolphins are largely marine animals, although some species (such as the Sotalia or the porpoise ) are often found in freshwater. The various groups of river dolphins , previously considered close relatives of dolphins, are only distantly related to these three groups.
- Laura May-Collado and Ingi Agnarsson: Cytochrome b and Bayesian inference of whale phylogeny, PDF (387 kB)
- Michel C. Milinkovitch, Axel Meyer and Jeffrey R. Powell: Phylogeny of All Major Groups of Cetaceans Based on DNA Sequences from Three Mitochondrial Genes, PDF (1.59 MB)
- The Paleobiology Database as of March 6, 2005