Artiodactyla (Even-toed ungulates and cetaceans)

The even-toed ungulates (Artiodactyla, from Ancient Greek ἄρτιος (ártios), meaning ‘even’, and δάκτυλος (dáktylos), meaning ‘finger/toe’) are ungulates (hoofed quadrupeds) whose weight is borne equally by the third and fourth toes. By contrast, odd-toed ungulates, such as horses, bear their weight primarily on their third toes. The aquatic cetaceans (whales, dolphins, and porpoises) evolved from within even-toed ungulates, so modern taxonomic classification sometimes combines the Artiodactyla and Cetacea into the Cetartiodactyla.

— Wikipedia