Hominoid taxonomies
1 August 2001
ScienceWeek

The terms "hominoid", "hominid", and "hominin" are not interchangeable, but their classification criteria are variously in a state of flux. In general, the hominoids are a primate superfamily; the hominid family is currently considered to comprise both the great ape lineages and human lineages within the hominoid superfamily; the "homininae" comprise both the human lineages and the African ape lineages within the hominids, and the "hominini" comprising only the human lineages. The current scheme is as follows:

1. Suborder Hominoids (a primate superfamily)
   1. ...
   2. Family Hominids
      1. ...
      2. Subfamily Homininae (see images)
         1. Tribe Gorillini (African apes)
         2. Tribe Hominini (human linages)
            (1) Genus Ardipithecus
            (2) Genus Australopithecus
            (3) Genus Paranthropus
            (4) Genus Kenyanthropus
            (5) Genus Homo

The term "hominins" almost always refers to the tribe Hominini, and not to the subfamily Homininae. It is important to note that in the older scheme (before about 1980), the Hominoids comprised the gibbons (Hylobatidae), the great apes (Pongidae), and the Hominidae, with the Hominidae (hominids) consisting only of the two genera Homo and Australopithecus. The new scheme is therefore considerably different. For example, under the old scheme, the statement "modern man is the only living hominid" is correct. Under the new scheme, that statement is incorrect.

The human lineages (the hominins) are characterized by a number of features, including bipedalism. In effect, hominins are the group of fossils more closely related to modern humans than to any other group. In terms of dating, the hominin group apparently originated sometime between 5 and 8 million years ago. Concerning the "apes", there are two categories of relevance here: The term "great apes" refers to chimpanzees, gorillas, and orangutans. The term "African apes" refers only to chimpanzees and gorillas. The distinction is important, since on the basis of molecular evidence, the African apes are close to humans, while the orangutans are not that close, and the gibbons are even further removed.

The classification and interpretation of hominin fossils has never been free of controversy, partly because hominin fossils are not that plentiful, and perhaps partly because there are a number of rival discovery teams, and the significance of a new hominin fossil discovery is enhanced if the discovery apparently requires new classifications and/or new interpretations.

Source

For a simpler taxonomy, see Hominidae in the Tree of Life site at the University of Arizona, with an excellent list of references.