Abstract
Many researchers have suggested that Australopithecus anamensis and Australopithecus afarensis were among the earliest hominins to have diets that included hard, brittle items. Here we examine dental microwear textures of these hominins for evidence of this. The molars of three Au. anamensis and 19 Au. afarensis specimens examined preserve unobscured antemortem microwear. Microwear textures of these individuals closely resemble those of Paranthropus boisei, having lower complexity values than Australopithecus africanus and especially Paranthropus robustus. The microwear texture complexity values for Au. anamensis and Au. afarensis are similar to those of the grass-eating Theropithecus gelada and folivorous Alouatta palliata and Trachypithecus cristatus. This implies that these Au. anamensis and Au. afarensis individuals did not have diets dominated by hard, brittle foods shortly before their deaths. On the other hand, microwear texture anisotropy values for these taxa are lower on average than those of Theropithecus, Alouatta or Trachypithecus. This suggests that the fossil taxa did not have diets dominated by tough foods either, or if they did that directions of tooth–tooth movement were less constrained than in higher cusped and sharper crested extant primate grass eaters and folivores.
References
-
Altmann S. A. . 1998 Foraging for survival: yearling baboons in Africa. Chicago, IL: University of Chicago Press. Google Scholar -
Bentley-Condit V. K. . 2009 Food choices and habitat use by the Tana River yellow baboons (Pap. cynocephalus): a preliminary report on five years of data. Am. J. Primatol. 71, 432–436. (doi:10.1002/ajp.20670). Crossref, PubMed, ISI, Google Scholar -
Bock W. J.& von Wahlert G. . 1965 The role of ecological factors in the origin of higher levels of organization. Syst. Zool. 14, 272–300. (doi:10.2307/2411681). Crossref, PubMed, Google Scholar -
Conover W. J.& Iman R. L. . 1981 Rank transformations as a bridge between parametric and nonparametric statistics. Am. Stat. 35, 124–129. (doi:10.2307/2683975). ISI, Google Scholar -
Cook R. J.& Farewell V. T. . 1996 Multiplicity considerations in the design and analysis of clinical trials. J. R. Stat. Soc. 159, 93–110. Crossref, Google Scholar -
de Ruiter D. J., Steininger C. M.& Berger L. R. . 2006 A cranial base of Australopithecus robustus from the hanging remnant of Swartkrans, South Africa. Am. J. Phys. Anthropol. 130, 435–444. (doi:10.1002/ajpa.20386). Crossref, PubMed, ISI, Google Scholar -
Dunbar R. I. M. . 1988 Primate social systems. Ithaca, NY: Cornell University Press. Crossref, Google Scholar -
El-Zaatari S. . 2008 Occlusal microwear texture analysis and the diets of historical/prehistoric hunter-gatherers. Int. J. Osteoarchaeol 20, 67–87. (doi:10.1002/oa.1027). ISI, Google Scholar -
Falk D. . 1988 Enlarged occipital/marginal sinuses and emissary foramina: their significance in hominid evolution. Evolutionary history of the ‘robust’ australopithecines (ed.& Grine F. E. ), pp. 85–96. New York, NY: Aldine de Gruyter. Google Scholar -
Falk D.& Conroy G. C. . 1983 The cranial venous sinus system in Australopithecus afarensis. Nature 306, 779–781. (doi:10.1038/306779a0). Crossref, ISI, Google Scholar -
Grine F. E. . 1977 Analysis of early hominid deciduous molar wear by scanning electron microscopy: a preliminary report. Proc. Electr. Microscop. Soc. S. Afr. 7, 157–158. Google Scholar -
Grine F. E. . 1981 Trophic differences between ‘gracile’ and ‘robust’ australopithecines: a scanning electron microscope analysis of occlusal events. S. Afr. J. Sci. 77, 203–230. ISI, Google Scholar -
Grine F. E. . 1986 Dental evidence for dietary differences in Australopithecus and Paranthropus: a quantitative analysis of permanent molar microwear. J. Hum. Evol. 15, 783–822. (doi:10.1016/S0047-2484(86)80010-0). Crossref, ISI, Google Scholar -
Grine F. E.& Strait D. S. . 2000 The phylogenetic relationships of recently described early hominid species. Am. J. Phys. Anthropol. ((Suppl. 30)), 167. Google Scholar -
Grine F. E., Ungar P. S.& Teaford M. F. . 2006 a Was the Early Piocene hominin ‘Australopithecus’ anamensis a hard object feeder? S. Afr. J. Sci. 102, 301–310. ISI, Google Scholar -
Grine F. E., Ungar P. S., Teaford M. F.& El-Zaatari S. . 2006 b Molar microwear in Praeanthropus afarensis: evidence for dietary stasis through time and under diverse paleoecological conditions. J. Hum. Evol. 51, 297–319. (doi:10.1016/j.jhevol.2006.04.004). Crossref, PubMed, ISI, Google Scholar -
Hylander W. L. . 1988 Implications of in vivo experiments for interpreting the functional significance of ‘robust’ australopithecine jaws. Evolutionary history of the ‘robust’ australopithecines (ed.& Grine F. E. ), pp. 55–83. New York, NY: Aldine de Gruyter. Google Scholar -
Kay R. F.& Hiiemae K. M. . 1974 Jaw movement and tooth use in recent and fossil primates. Am. J. Phys. Anthropol. 40, 227–256. (doi:10.1002/ajpa.1330400210). Crossref, PubMed, ISI, Google Scholar -
Kimbel W. H. . 1984 Variation in the pattern of cranial venous sinuses and hominid phylogeny. Am. J. Phys. Anthropol. 63, 243–263. (doi:10.1002/ajpa.1330630302). Crossref, PubMed, ISI, Google Scholar -
Kimbel W. H., Rak Y.& Johanson D. C. . 2004 The skull of Australopithecus afarensis. New York, NY: Oxford University Press. Crossref, Google Scholar -
Kimbel W. H., Lockwood C. A., Ward C. V., Leakey M. G., Rak Y.& Johanson D. C. . 2006 Was Australopithecus anamensis ancestral to A. afarensis? A case of anagenesis in the hominin fossil record. J. hum. Evol. 51, 134–152. (doi:10.1016/j.jhevol.2006.02.003). Crossref, PubMed, ISI, Google Scholar -
Krueger K. L.& Ungar P. S. In press. Incisor microwear textures of five bioarcheological groups. Int. J. Osteoarcheol. (doi:10:1002/oz.1093). ISI, Google Scholar -
Krueger K. L., Scott J. R.& Ungar P. S. . 2008 Technical note: dental microwear textures of ‘Phase I’ and ‘Phase II’ facets. Am. J. Phys. Anthropol. 137, 485–490. (doi:10.1002/ajpa.20928). Crossref, PubMed, ISI, Google Scholar -
Macho G. A., Shimizu D., Jiang Y.& Spears L. R. . 2005 Australopithecus anamensis: a finite element approach to studying the functional adaptations of extinct hominins. Anat. Rec. 283A, 310–318. (doi:10.1002/ar.a.20175). Crossref, Google Scholar -
McHenry H. M. . 1984 Relative cheek tooth size in Australopithecus. Am. J. Phys. Anthropol. 64, 297–306. (doi:10.1002/ajpa.1330640312). Crossref, PubMed, ISI, Google Scholar -
Norton G. W., Rhine R. J., Wynn G. W.& Wynn R. D. . 1987 Baboon diet: a five-year study of stability and variability in the plant feeding and habitat of the yellow baboons (Pap. cynocephalus) of Mikumi National Park, Tanzania. Fol. Primatol. 48, 78–120. (doi:10.1159/000156287). Crossref, PubMed, ISI, Google Scholar -
Picq P. . 1990 The diet of Australopithecus afarensis: an attempted reconstruction. C. R. Acad. Sci. Ser. II 311, 725–730. Google Scholar -
Plavcan J. M.& Cope D. A. . 2001 Metric variation and species recognition in the fossil record. Evol. Anthropol. 10, 204–222. (doi:10.1002/evan.20001). Crossref, ISI, Google Scholar -
Pochron S. T. . 2000 The core dry-season diet of yellow baboons (Papio hamadryas cynocephalus) in Ruaha National Park, Tanzania. Fol. Primatol. 71, 346–349. (doi:10.1159/000021758). Crossref, PubMed, ISI, Google Scholar -
Post D. G. . 1982 Feeding behavior of yellow baboons (Papio cyncocephalus) in the Amboseli National Park, Kenya. Int. J. Primatol. 3, 403–430. (doi:10.1007/BF02693741). Crossref, Google Scholar -
Puech P. F. . 1979 Diet of early man: evidence from abrasion of teeth and tools. Curr. Anthropol. 20, 590–592. (doi:10.1086/202335). Crossref, ISI, Google Scholar -
Rak Y., Ginzburg A.& Geffen E. . 2007 Gorilla-like anatomy on Australopithecus afarensis mandibles suggests Au. afarensis link to robust australopiths. Proc. Natl Acad. Sci. USA 104, 6568–6572. (doi:10.1073/pnas.0606454104). Crossref, PubMed, ISI, Google Scholar -
Ryan A. S. . 1980 Anterior dental microwear in hominid evolution: comparisons with human and nonhuman primates. PhD dissertation, University of Michigan. Google Scholar -
Scott R. S., Ungar P. S., Bergstrom T. S., Brown C. A., Grine F. E., Teaford M. F.& Walker A. . 2005 Dental microwear texture analysis reflects diets of living primates and fossil hominins. Nature 436, 693–695. (doi:10.1038/nature03822). Crossref, PubMed, ISI, Google Scholar -
Scott R. S., Ungar P. S., Bergstrom T. S., Brown C. A., Childs B. E., Teaford M. F.& Walker A. . 2006 Dental microwear texture analysis: technical considerations. J. Hum. Evol. 51, 339–349. (doi:10.1016/j.jhevol.2006.04.006). Crossref, PubMed, ISI, Google Scholar -
Scott J. S., Godfrey L. R., Jungers W. L., Scott R. S., Simons E. L., Teaford M. F., Ungar P. S.& Walker A. . 2009 a Dental microwear texture anlaysis of megaladapids and archaeolemurids. J. Hum. Evol. 56, 405–416. (doi:10.1016/j.jhevol.2008.11.003). Crossref, PubMed, ISI, Google Scholar -
Scott R. S., Teaford M. F.& Ungar P. S. . 2009 b Dietary diversity and dental microwear variability in Theropithecus gelada and Pap. cynocephalus. Am. J. Phys. Anthropol. ((Suppl. 48)), 234. PubMed, ISI, Google Scholar -
Strait D. S.& Grine F. E. . 2004 Inferring hominoid and early hominid phylogeny using craniodental characters: the role of fossil taxa. J. Hum. Evol. 47, 399–452. (doi:10.1016/j.jhevol.2004.08.008). Crossref, PubMed, ISI, Google Scholar -
Strait D. S., Grine F. E.& Moniz M. A. . 1997 A reappraisal of early hominid phylogeny. J. Hum. Evol. 32, 17–82. (doi:10.1006/jhev.1996.0097). Crossref, PubMed, ISI, Google Scholar -
Suwa G., Kono R. T., Simpson S. W., Asfaw B., Lovejoy C. O.& White T. D. . 2009 Paleobiological implications of the Ardipithecus ramidus dentition. Science 326, 94–99. (doi:10.1126/science.1175824). Crossref, PubMed, ISI, Google Scholar -
Teaford M. F. . 1988 Scanning electron microscope diagnosis of wear patterns versus artifacts on fossil teeth. Scan. Microsc. 2, 1167–1175. PubMed, Google Scholar -
Teaford M. F.& Ungar P. S. . 2000 Diet and the evolution of the earliest human ancestors. Proc. Natl. Acad. Sci. USA 97, 13 506–13 511. (doi:10.1073/pnas.260368897). Crossref, ISI, Google Scholar -
Ungar P. S. . 2004 Dental topography and diets of Australopithecus afarensis and early Homo. J. Hum. Evol. 46, 605–622. (doi:10.1016/j.jhevol.2004.03.004). Crossref, PubMed, ISI, Google Scholar -
Ungar P. S.& Scott R. S. . 2009 Dental evidence for diets of Early Homo. The first humans: origins of the genus Homo (eds, Grine F. E., Leakey R. E.& Fleagle J. G. ), pp. 121–134. New York, NY: Springer-Verlag. Google Scholar -
Ungar P. S.& Teaford M. F. . 2001 The dietary split between apes and the earliest human ancestors. Humanity from African naissance to coming millennia (ed., Tobias P. V., ), pp. 337–354. Florence, Italy: Firenza University Press. Google Scholar -
Ungar P. S., Brown C. A., Bergstrom T. S.& Walker A. . 2003 Quantification of dental microwear by tandem scanning confocal microscopy and scale-sensitive fractal analyses. Scanning 25, 185–193. (doi:10.1002/sca.4950250405). Crossref, PubMed, ISI, Google Scholar -
Ungar P. S., Grine F. E., Teaford M. F.& El Zaatari S. . 2006 Dental microwear and diets of African early Homo. J. Hum. Evol. 50, 78–95. (doi:10.1016/j.jhevol.2005.08.007). Crossref, PubMed, ISI, Google Scholar -
Ungar P. S., Merceron G.& Scott R. S. . 2007 a Dental microwear texture analysis of Varswater bovids and Early Pliocene paleoenvironments of Langebaanweg, Western Cape Province, South Africa. J. Mammal. Evol. 14, 163–181. (doi:10.1007/s10914-007-9050-x). Crossref, Google Scholar -
Ungar P. S., Scott R. S., Scott J. R.& Teaford M. F. . 2007 b Dental microwear analysis: historical perspectives and new approaches. Dental anthropology (eds, Irish J. D.& Nelson G. C. ), pp. 389–425. Cambridge, UK: Cambridge University Press. Google Scholar -
Ungar P. S., Grine F. E.& Teaford M. F. . 2008 Dental microwear indicates that Paranthropus boisei was not a hard-object feeder. PLoS ONE 3, 1–6. Google Scholar -
van der Merwe N. J., Masao F. T.& Bamford M. K. . 2008 Isotopic evidence for contrasting diets of early hominins Homo habilis and Australopithecus boisei of Tanzania. S. Afr. J. Sci. 104, 153–155. ISI, Google Scholar -
Walker A. . 1981 Diet and teeth. Dietary hypotheses and human evolution. Phil. Trans. R. Soc. Lond. B 292, 57–64. (doi:10.1098/rstb.1981.0013). Link, ISI, Google Scholar -
Walker A. . 2002 New perspectives on the hominids of the Turkana Basin, Kenya. Evol. Anthropol. 11((Suppl. 1)), 38–41. Google Scholar -
Ward C. V., Leakey M. G.& Walker A. C. . 1999 The new hominid species, Australopithecus anamensis. Evol. Anthropol. 7, 197–205. (doi:10.1002/(SICI)1520-6505(1999)7:6<197::AID-EVAN4>3.0.CO;2-T). Crossref, ISI, Google Scholar -
Ward C. V., Leakey M. G.& Walker A. . 2001 Morphology of Australopithecus anamensis from Kanapoi and Allia Bay, Kenya. J. Hum. Evol. 41, 255–368. (doi:10.1006/jhev.2001.0507). Crossref, PubMed, ISI, Google Scholar -
White T. D., Johanson D. C.& Kimbel W. H. . 1981 Australopithecus africanus: its phyletic position reconsidered. S. Afr. J. Sci. 77, 445–470. ISI, Google Scholar -
White T. D., Suwa G., Simpson S.& Asfaw B. . 2000 Jaws and teeth of Australopithecus afarensis from Maka, Middle Awash, Ethiopia. Am. J. Phys. Anthropol. 111, 45–68. (doi:10.1002/(SICI)1096-8644(200001)111:1<45::AID-AJPA4>3.0.CO;2-I). Crossref, PubMed, ISI, Google Scholar -
White T. D., 2006 Asa Issie, aramis and the origin of Australopithecus. Nature 440, 883–889. (doi:10.1038/nature04629). Crossref, PubMed, ISI, Google Scholar -
Wood B.& Richmond B. G. . 2000 Human evolution: taxonomy and paleobiology. J. Anat. 197, 19–60. (doi:10.1046/j.1469-7580.2000.19710019.x). Crossref, PubMed, ISI, Google Scholar