Earliest Homo
baringo; calibration; east; fossil hominids; kenya; pliocene; region; Science & Technology - Other Topics; turkana
THE origin of our own genus, Homo, has been tentatively correlated with worldwide climatic cooling documented at about 2.4 Myr (million years) (refs 1-5). It has also been conjectured that members of Homo made the first stone tools, currently dated at 2.6 - 2.4 Myr (refs 6-8). But fossil specimens clearly attributable to Homo before about 1.9 Myr have been lacking. In 1967 a fossil hominoid temporal bone (KNM-BC1) from the Chemeron Formation of Kenya was described as family Hominidae gen. et sp. indet. 9. Although a surface find, its provenance within site JM85 (BPRP site K002) was established and a stratigraphic section provided indicating the specimen's position 9. This evidence has been affirmed (see for example refs 10-12) but the exact age of the fossil was never determined, and the absence of suitable comparative hominid material has precluded a more definitive taxonomic assignment. Here we present Ar-40/Ar-39 age determinations on material from the hominid site indicating an age of 2.4 Myr. In addition, comparative studies allow us to assign KNM-BC1 to the genus Homo, making it the earliest securely known fossil of our own genus found so far.
Hill A; Ward S; Deino A; Curtis G; Drake R
Nature
1992
1992-02
Journal Article or Conference Abstract Publication
<a href="http://doi.org/10.1038/355719a0" target="_blank" rel="noreferrer noopener">10.1038/355719a0</a>
Anatomy And Age Of The Lothagam Mandible
Anthropology; baringo; dating; east-africa; Evolutionary Biology; faunal change; fossil hominids; hominidae; kenya; late miocene; lothagam; mandible; pliocene; tanzania
Hill A; Ward S; Brown B
Journal of Human Evolution
1992
1992-06
Journal Article or Conference Abstract Publication
<a href="http://doi.org/10.1016/0047-2484(92)90079-o" target="_blank" rel="noreferrer noopener">10.1016/0047-2484(92)90079-o</a>
Subnasoalveolar anatomy and hominoid phylogeny: Evidence from comparative ontogeny
Anthropology; Evolutionary Biology; evolution; allometry; great apes; miocene; form; sexual dimorphism; extant; fossil hominids; Homo; late; african apes; facial kyphosis; character phylogeny; chimp; hylobatids; ontogenetic; orangutans; skull material; subnasal development
The present analysis evaluated extant hominoid subnasal morphological variation from an ontogenetic perspective, documenting both qualitative and allometric details of subnasal maturation in Hylobates, great apes and modern humans. With respect to intraspecific variation, results of log-linear modeling procedures indicate that qualitative features of the subnasal region shown previously to discriminate extant taxa (Ward and Kimbel, 1983; McCollum et al., 1993) do not vary appreciably with either age or sex. In terms of quantitative variation, aside from observed changes in the position of the anterior attachment of the nasal septal cartilage relative to the lateral margins of the nasal cavity, the morphology of the subnasal region does not vary appreciably with age. Furthermore, it was found that sexual dimorphism in subnasal form is present only in Pongo and Gorilla and is the result of sexual bimaturism rather than sexual variation in canine size. In considering interspecific variation in subnasal form, there is a propensity among hominoid taxa for the nasal cavity floor to be free of substantial topographic relief. The smoothly continuous nasal floor topography identified in the majority of hominoid taxa appears to be produced by extensive resorption of the anterior nasal cavity floor that accompanies an upward rotation of the anterior maxilla during craniofacial ontogeny. Comparisons of ontogenetic allometric trajectories indicate that relatively little of the variation in hominoid subnasal form can easily be attributed to variation in body/cranial size. Instead, variation in craniofacial orientation, vascular anatomy and incisor size and inclination were identified as potential mediators of hominoid subnasoalveolar anatomy. Although results of this analysis confirm that many details of the orangutan subnasal morphology are derived for this taxon, there is little conclusive evidence to support recent reports that the morphology displayed by Gorilla is primitive for great apes (Begun, 1992, 1994). (C) 1997 Wiley-Liss, Inc.
McCollum M A; Ward S C
American Journal of Physical Anthropology
1997
1997-03
Journal Article or Conference Abstract Publication
<a href="http://doi.org/10.1002/(sici)1096-8644(199703)102:3%3C377::aid-ajpa7%3E3.0.co;2-s" target="_blank" rel="noreferrer noopener">10.1002/(sici)1096-8644(199703)102:3%3C377::aid-ajpa7%3E3.0.co;2-s</a>
The taxonomic status of the Chemeron temporal (KNM-BC 1)
Anthropology; australopithecus-africanus; Chemeron temporal; earliest homo; Evolutionary Biology; extant; fossil hominids; hadar formation; hominoids; Homo; lake turkana; meningeal vascular patterns; plio-pleistocene hominids; south-africa; swartkrans formation; temporal bone
Temporal bone morphology, as part of the basicranium, is commonly used in systematic evaluation of early hominid fossils. When an isolated right temporal bone, KNM-BC 1 (the Chemeron temporal) was discovered in the Baringo Basin, Kenya, Tobias (1967a, Nature 215, 476-480), citing ambiguity of characters, hesitated to place the specimen generically, attributing the fossil only to Hominidae gen. et sp. indet. Since that discovery, the early hominid sample has grown considerably and comparisons with this expanded dataset led Hill et al. (1992a, Nature 355, 719-722) to revise the placement of KNM-BC 1 including it within the genus Homo. This revision was possible due to the increased number of hominid fossil specimens from the late Pliocene/early Pleistocene, most notably members of the genus Homo. A thorough investigation into the utility of the temporal bone in hominid systematics shows that many features, as currently used. in the literature, demonstrate high levels of variation thus questioning their phyletic valence. It is shown, however, that the temporal bone still contains useful systematic information. A detailed anatomical description of KNM-BC 1 is provided and, when discussed in the context of temporal bone features provided, affirms the conclusion of Hill et al. (1992a) and places the fossil within the genus Homo. (C) 2002 Academic Press.
Sherwood R J; Ward S C; Hill A
Journal of Human Evolution
2002
2002-01
Journal Article
<a href="http://doi.org/10.1006/jhev.2000.0409" target="_blank" rel="noreferrer noopener">10.1006/jhev.2000.0409</a>