Ungulata
Ongulés ( Ungulata ) - of the Greek onykos , then of Latin ungula , “nail” - form a traditional Taxon of Mammifère S considered as obsolete and Polyphylétique. Defined as gathering the species going on the end of the fingers, it is in fact an example of evolutionary Convergence. Ongulés initially formed a superorder gathering six orders of mammals:
-
the Artiodactyle S: who have an even number of fingers: Goat, Pig, Hippopotamus, Cow, etc
- the Périssodactyle S: who have an odd number of fingers: Horse, Rhinoceros, Tapir.
- the Proboscidiens: elephant.
- the Siréniens: Dugong and Manatee.
- the Hyracoïdes: daman.
- the Tubulidentés: Oryctérope.
Good number of these species have one or more shoe S at the end of their members. The shoe is then a formation cornea (such as the Ongle at the Primate S) very developed, and which wraps the Doigt S resting on the ground at the time of walk.
Paleontological and genetic revolution
According to the modern Taxonomy, this group is debatable. During the years 1960, one initially thought that the group was Monophylétique, once included the Cétacé S like seventh order with the Artiodactyle S (thus forming the Cétartiodactyles). By excluding the Cetacea, this group was known as Paraphylétique, not including/understanding all the species which result from one or more species of the group.The recent genetic analyzes shows that the Proboscidiens, Siréniens, Hyracoïdes are relatively distant. The taxon of ongulés is then completely artificial and one could qualify it Polyphylétique, because it would gather descendants of distinct ancestors. Moreover, the two groups (Cétartiodactyles, Périssodactyles) would be foreign within a taxon also gathering the carnivorous Chiroptère S, and the Pholidotes.
Old systematic
See also: phylogenetic Classification of alive (first edition) the
- ongulés
- tubulidentés
- Cétongulés
See too
Related article
- History of the Cetacea
External bonds
Simple: Ungulate
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