Under the formal rules for naming species, each species must have a type specimen. The 'type description' of a species describes the type specimen, and the similarities to and differences from closely related species. Another fossil belongs to the same species if and only if it belongs to the same species as the type specimen. Obviously this is a subjective assessment, but this rule ensures that all scientists are at least using the same criteria when trying to allocate specimens to species. When scientific thinking about the classification of specimens changes, there are complicated rules which determine how specimens should be allocated to species.
If two type specimens are later determined to belong to the same species, then the first one named takes priority. For example, when it was decided that the 2nd known australopithecine fossil, assigned to Plesianthropus transvaalensis, actually belonged to the same species as the first, that name became invalid and all Plesianthropus fossils were reassigned to Australopithecus africanus.
If it is decided that the fossils previously assigned to a species actually belong to two different species, then the type specimen and any other specimens belonging to the same species as it keep the old name. The other fossils will take the name of whichever specimen among them is first used as a type specimen for a new species definition. An example is Homo habilis (type specimen OH 7); the species Homo rudolfensis, with type specimen ER 1470, consists of fossils formerly assigned to habilis.
Homo habilis is a controversial species, with much disagreement over which specimens belong in habilis, and which do not. A number of scientists now use the name H. rudolfensis to refer to ER 1470 and some similar fossils. The smaller habilis-like specimens such as ER 1813 and ER 1805 are variously assigned to habilis, H. ergaster, or to another as yet unnamed species. The name H. microcranous has been proposed for ER 1813, but is virtually never used. Wood and Collard (1999) have argued on theoretical grounds that H. habilis and H. rudolfensis should be moved into the genus Australopithecus. The latest development in this debate is the discovery of OH 65, a fossil jaw from Olduvai Gorge.
It has been proposed that the names Homo heidelbergensis and Homo neanderthalensis should be restored as species names for archaic Homo sapiens and the Neandertals. Recent claims of genetic and anatomical differences between modern humans and Neandertals have added support to a species status for Homo neanderthalensis. (Krings et al. 1997; Hublin et al. 1996; Tattersall and Schwartz 1996)
Java Man (Pithecanthropus erectus) and Peking Man (Sinanthropus pekinensis) were originally assigned not only to different species, but different genera from Homo sapiens. Scientists such as Boule who considered them in the same genus but not the same species would sink Sinanthropus as a genus and call Peking Man Pithecanthropus pekinensis. Most scientists soon decided they were in the same species, so the Peking Man specimens were reassigned to P. erectus because that name had priority over S. pekinensis. Later, when it was decided that P. erectus was in the same genus as Homo sapiens, the genus name Pithecanthropus was sunk and the specific name erectus was kept, so the species became Homo erectus.
There is no central authority which proclaims that, for example, Homo ergaster is henceforth a valid species. Instead, the fate of a species name depends on the extent to which scientists accept the claim of its namers that it a valid species distinguishable from all others. Many of the following species names are not used in these pages, either because they are rarely used, or are so new that there is as yet no consensus on their validity.
Where two species names are given, the first is the one which was given by the original namer of the fossil, and the second name is the one by which it is usually known now. This often occurs when the genus name originally assigned is rejected and the fossil is placed in another genus.
For anyone interested in the naming and classification of hominids, an indispensable reference is Naming our Ancestors (Meikle and Parker, 1994). This useful book contains an introduction to the terms and principles of taxonomy, reprints of 15 sources in which hominid species were first named, and reprints of four papers which have been very influential in hominid taxonomy.
|Species||Type Specimen||Named By|
|Sahelanthropus tchadensis||TM 266-01-060-1||Brunet et al. 2002|
|Orrorin tugenensis||BAR 1000'00||Senut et al. 2001|
|Ardipithecus kadabba||ALA-VP 2/10||Haile-Selassie 2001|
|ARA-VP 6/1||White et al. 1994|
|Australopithecus anamensis||KP 29281||M. Leakey et al. 1995|
|Australopithecus afarensis||LH 4||Johanson et al. 1978|
|Homo antiquus||AL 288-1||Ferguson 1984|
|Australopithecus bahrelghazali||KT 12/H1||Brunet et al. 1996|
|Kenyanthropus platyops||KNM-WT 40000||M. Leakey et al. 2001|
|Australopithecus africanus||Taung||Dart 1925|
|Australopithecus garhi||BOU-VP-12/130||Asfaw et al. 1999|
|Omo 18||Arambourg & Coppens 1968|
|TM 1517||Broom 1938|
|Australopithecus walkeri||KNM-WT 17000||Ferguson 1989|
|Australopithecus sediba||MH1||Berger et al. 2010|
|OH 5||L. Leakey 1959|
|SK 6||Broom 1949|
|Homo antiquus praegens
|KNM-T1 13150||Ferguson 1989|
|Homo habilis||OH 7||L. Leakey et al. 1964|
|Homo louisleakeyi||OH 9||Kretzoi 1984|
|KNM-ER 1470||Alexeev 1986|
|Homo microcranous||KNM-ER 1813||Ferguson 1995|
|Homo gautengensis||Stw-53||Curnoe 2010|
|Homo naledi||DH1||Berger et al. 2015|
|Homo georgicus||D2600||Gabunia et al. 2002|
|Homo ergaster||KNM-ER 992||Groves & Mazak 1975|
|Trinil 2||Dubois 1894|
|Homo cepranensis||Ceprano||Mallegni et al. 2003|
|Homo antecessor||ATD6-5||Bermudez de Castro et al. 1997|
|Homo heidelbergensis||Mauer 1||Schoetensack 1908|
|Homo rhodesiensis||Kabwe||Woodward 1921|
|Homo helmei||Florisbad||Dreyer 1935|
|Homo neanderthalensis||Neandertal 1||King 1864|
|Homo floresiensis||LB1||Brown et al. 2004|
|Homo sapiens||-||Linnaeus 1758|
Meikle W.E. and Parker S.T. (1994): Naming our Ancestors: an anthology of hominid taxonomy. Prospect Heights, Illinois: Waveland Press.
International Code of Zoological Nomenclature
Curiosities of Biological Nomenclature, by Mark Isaak
This page is part of the Fossil Hominids FAQ at the talk.origins Archive.
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