Primates

, Volume 46, Issue 1, pp 21–32 | Cite as

Incisor-molar relationships in chimpanzees and other hominoids: implications for diet and phylogeny

Original Article

Abstract

In chimpanzees, the cutting edge of the incisor battery is longer in relation to the length of the molar row than in any other hominoid, extant or fossil, the only other lineage approaching it being the orangutan. Apart from their increased mesio-distal dimensions, the upper and lower incisors of chimpanzees differ in additional ways from those of almost all other hominoids. The I2/ is enlarged, so that the difference in size between it and the central upper incisor is less than it is in the heteromorphic upper incisors of other hominoids. The lower incisors are expanded mesio-distally, so much so that isolated I/2 crowns can resemble upper central incisors. In chimpanzees the lingual surface of the lower incisors is generally more procumbent than it is in other hominoids, which have more vertically oriented incisor crowns and there is a greater difference in enamel thickness between labial and lingual sides. The re-orientation of the lower incisor crown is reflected in the root, which in lateral view is anteriorly concave in chimpanzees whereas it is more orthogonal or convex in other hominoids. The molars of chimpanzees, especially the lowers, have extensive and relatively deep occlusal basins, and the main cusps are peripheralised and labio-lingually compressed, making them more trenchant than those of other hominoids. This paper examines the incisor-lower molar proportions in extinct and living hominoids and develops a new hypothesis about the evolution of the dentition of chimpanzees and links it to their diet. It also examines the incisor-molar proportions of hominids and African apes in order to throw light on the phylogenetic relationships between them. It is shown that chimpanzees are highly derived in this respect and that several recent ideas concerning the chimp-like appearance of the last common ancestor of hominids and African apes are likely to be incorrect.

Keywords

Hominoidea Incisors Molars Meat-eating Phylogeny 

References

  1. Arnason U, Gullberg A, Janke A, Xiufeng Xu (1996) Pattern and timing of evolutionary divergences among hominoids based on analyses of complete mtDNAs. J Mol Evol 43:650–651PubMedGoogle Scholar
  2. Arnason U, Gullberg A, Janke A (1998) Molecular timing of Primate divergences as estimated by two nonprimate calibration points. J Mol Evol 47:718–727PubMedGoogle Scholar
  3. Arnason U, Gullberg A, Schweitzer Burguette A, Janke A (2000) Molecular estimates of Primate divergences and new hypotheses for Primate dispersals and the origin of modern humans. Hereditas 133:217–228PubMedGoogle Scholar
  4. Badrian N, Malenky R (1984) Feeding ecology of Pan paniscus in the Lomako Forest, Zaire. In: Susman RL (ed) The pygmy chimpanzee. Plenum, New York, pp 275–300Google Scholar
  5. Boesch C, Boesch H (2000) The chimpanzees of the Taï forest: behavioural ecology and evolution. Oxford University Press, OxfordGoogle Scholar
  6. Gagneux P, Wills C, Gerloff U, Tautz D, Morin P, Boesch C, Fruth B, Hohmann G, Ryder O, Woodruff D (1999) Mitochondrial sequences show diverse evolutionary histories of African hominoids. Proc Natl Acad Sci USA 96:5077–5082PubMedGoogle Scholar
  7. Hasegawa M, Yano T (1984) Phylogeny and classification of Hominoidea as inferred from DNA sequence data. Proc Jpn Acad 60:389–392Google Scholar
  8. Hasegawa M, Kishino H, Yano T (1985) Dating of the human-ape splitting by a molecular clock of mitochondrial DNA. J Mol Evol 22:160–174PubMedGoogle Scholar
  9. Hosaka K (2000) Mammal hunting and meat-eating of chimpanzees. Anthropol Sci 108:72Google Scholar
  10. Janke A, Arnason U (2002) Primate divergence times. In: Galdikas B, Briggs N, Sheeran L, Shapiro G, Goodall J (eds) All apes great and small. African apes, vol 1. Kluwer/Plenum, New York , pp 18–25Google Scholar
  11. Kono RT (2004) Molar enamel thickness and distribution pattern in extant great apes and humans: new insights based on a 3-dimensional whole crown perspective. Anthropol Sci 112:121–146Google Scholar
  12. Kumar S, Hedges S (1998) A molecular timescale for vertebrate evolution. Nature 392:917–920PubMedGoogle Scholar
  13. Latimer B, White T, Kimbel W, Johanson D, Lovejoy O (1981) The pygmy chimpanzee is not a living missing link in human evolution. J Hum Evol 10:475–488Google Scholar
  14. Mitani J, Watts D (2001) Why do chimpanzees hunt and share meat? Anim Behav 61:915–924Google Scholar
  15. Mitani J, Watts D, Muller M (2002) Recent developments in the study of wild chimpanzee behavior. Evol Anthropol 11:9–25Google Scholar
  16. Pickford M (1986a) On the origins of body size dimorphism in primates. Human Evol 1:77–90Google Scholar
  17. Pickford M (1986b) Sexual dimorphism inProconsul. Human Evol 1:111–148Google Scholar
  18. Pickford M (1986c) Sex differences in higher primates: a summary statement. In: Pickford M, Chiarelli AB (eds) Sexual dimorphism in living and fossil primates. Il Sedicesimo, Firenze, pp 191–199Google Scholar
  19. Pilbeam D (1969) Tertiary Pongidae of East Africa: evolutionary relationships and taxonomy. Bull Peabody Mus Nat Hist 31:1–185Google Scholar
  20. Sarich V, Wilson A (1967) Immunological time scale for hominid evolution. Science 158:1200–1202PubMedGoogle Scholar
  21. Sibley C, Ahlquist J (1984) The phylogeny of the hominoid primates, as indicated by DNA–DNA hybridization. J Mol Evol 20:2–15PubMedGoogle Scholar
  22. Stauffer RL, Walker A, Ryder O, Lyons-Wailer M, Hedges S (2001) Human and ape molecular clocks and constraints on paleontological hypotheses. Am Genet Assoc 92:469–474Google Scholar
  23. Watts D (2004) Intracommunity coalitionary killing of an adult male chimpanzee at Ngogo, Kibale National Park, Uganda. Int J Primatol 25(3):507–521Google Scholar
  24. Watts D, Mitani J (2002) Hunting behavior of chimpanzees at Ngogo, Kibale National Park, Uganda. Int J Primatol 23:1–28Google Scholar
  25. Wrangham R (2002) Fall back foods and cooking in human evolution. In: Evolution of the apes and the origin of human beings. International Symposium, Centre of Excellence, Inuyama, 14–17 November 2002, p 29Google Scholar
  26. Wrangham R, Pilbeam D (2001) African apes as time machines. In: Galdikas B, Briggs N, Sheeran L, Shapiro G, Goodall J (eds) All apes great and small.African apes, vol 1. Kluwer/Plenum, New York, pp 5–17Google Scholar
  27. Zihlman AL (1979) Pygmy chimpanzee morphology and the interpretation of early hominids. S Afr J Sci 75:165–167Google Scholar
  28. Zihlman A, Cronin J, Cramer D, Sarich V (1978) Pygmy chimpanzee as a possible prototype for the common ancestor of humans, chimpanzees and gorillas. Nature 275:744–746PubMedGoogle Scholar

Copyright information

© Japan Monkey Centre and Springer-Verlag 2005

Authors and Affiliations

  1. 1.Département Histoire de la Terre, UMR 5143 CNRSParisFrance
  2. 2.Collège de FranceParisFrance

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