Artiodactyl: Difference between revisions

'''Artiodactyls''' are [[Placentalia|placental mammal]]s belonging to the [[order (biology)|order]] '''Artiodactyla''' ({{IPAc-en|ˌ|ɑr|t|i|oʊ|ˈ|d|æ|k|t|ɪ|l|ə}} {{respell|AR|tee|oh|DAK|tih|lə}}, {{etymology|grc|''ἄρτιος'', ártios|even||''δάκτυλος'', dáktylos|finger, toe}}). Typically, they are [[ungulate]]s which bear weight equally on two (an even number) of their five toes (the third and fourth, often in the form of a [[hoof]]). The other three toes are either present, absent, [[vestigial]], or pointing posteriorly. By contrast, most [[perissodactyl]]s bear weight on an odd number of the five toes. Another difference between the two orders is that many artiodactyls (except for [[Suina]]) digest plant [[cellulose]] in one or more [[stomach]] chambers rather than in their [[intestine]] (as perissodactyls do). Molecular biology, along with new fossil discoveries, has found that cetaceans ([[whale]]s, [[dolphin]]s, and [[porpoise]]s) fall within this taxonomic branch, being most closely related to [[Hippopotamidae|hippopotamuses]]. Some modern taxonomists thus apply the name '''Cetartiodactyla''' ({{IPAc-en|s|ᵻ|ˌ|t|ɑr|t|i|oʊ|ˈ|d|æ|k|t|ɪ|l|ə}}) to this group, while others opt to include cetaceans within the existing name of Artiodactyla. Some researchers use "'''even-toed ungulates'''" to exclude cetaceans and only include terrestrial artiodactyls, making the term [[paraphyletic]] in nature.

 

 

==Evolutionary history==