The even-toed ungulates (order Artiodactyla, from Greek ἄρτιος (ártios), meaning "even", and δάκτυλος (dáktylos), meaning "finger/toe") are ungulates (hoofed animals) 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 toe. The aquatic Cetaceans (whales, dolphins, and porpoises) evolved from even-toed ungulate ancestors, and therefore modern taxonomic classification combines Artiodactyla and Cetacea into Cetiartiodactyla.