The even-toed ungulates (order Artiodactyla) are ungulates (hoofed animals) whose weight is borne approximately equally by the third and fourth toes, rather than mostly or entirely by the third as in odd-toed ungulates (perissodactyls), such as horses. The name Artiodactyla comes from (Greek: ἄρτιος (ártios), "even", and δάκτυλος (dáktylos), "finger/toe"), so the name "even-toed" is a translation of the description. This group includes pigs (family Suidae), peccaries (family Tayassuidae), hippopotamuses (family Hippopotamidae), camels (genus Camelus in family Camelidae), llamas (genus Lama in family Camelidae), chevrotains or mouse deer (family Tragulidae), deer (family Cervidae), giraffes (family Giraffidae), pronghorn (genus Antilocapra in family Antilocapridae), antelopes (sections of family Bovidae including subfamily Antilopinae), goat-antelopes (which include sheep, goats and others; subfamily Caprinae in family Bovidae), and cattle (genus Bos in family Bovidae). The group excludes whales (Cetacea), although DNA sequence and anatomical data indicate they share a common ancestor, making the group paraphyletic. The phylogenetically accurate group is called Cetartiodactyla (from Cetacea + Artiodactyla). Of the roughly 220 artiodactyl species, many are of great dietary, economic, and cultural importance to humans. A further distinguishing feature of the group is the shape of the astragalus (talus), a bone in the ankle joint, which has a double-pulley structure. This gives the foot greater flexibility. Video is targeted to blind users Attribution: Article text available under CC-BY-SA image Source in the video. =======Image-Info======= Image is in public domain Author-Info: Encyclopædia Britannica Image Source in the Video =======Image-Info========

• published: 06 Jul 2015
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