Abstract
One of the more important sources of variability in primate species is sexual dimorphism. Most Primates heavier than five kilos bodyweight are sexually dimorphic, both in body size and in shape of certain hard tissues. Despite these facts, most of the fossil Primates from East African Miocene deposits were originally perceived as being monomorphic, a perception which has propogated through the literature. Re-examination ofProconsul from various sites in Western Kenya results in the view that it was as dimorphic in its splanchonocranium and in bodyweight as chimpanzees and gorillas. The clearest evidence comes from Rusing Island, where adequate samples are known of two morphs, traditionally identified as two species, but more likely to represent two sexes of a single species,P. nyanzae. Co-occurrence of the two morphs is 100% at the various Rusinga sites. Less complete samples have been collected from the Tinderet sites os Koru and Songhor, yet what is available shows that similar patterns of dimorphism characterise the speciesP. africanus andP. major, and that the co-occurrence of the two morphs in each species is 100%. The identification of fossils taking into consideration the role of sexual dimorphism clarifies many of the old debates in which individual specimens frequently shifted between different species, mainly on the basis of metric rather than morphologic evidence. Consequently, the distribution of the species ofProconsul is rather different after accounting for dimorphism, than it was before.
Similar content being viewed by others
References
Andrews P. J., 1978.A revision of the Miocene Hominoidea of East Africa. Bull. Br. Mus. (Nat. Hist.) Geol., 30 (2): 85–224.
Andrews P. J., 1981.Species diversity and diet in monkeys and apes during the Miocene. In C. B. Stringer (ed). Aspects of Human Evolution London. Taylor and Francis, 25–61.
Andrews P. J. &Van Couvering J. A. H., 1975.Palaeoenvironments in the East African Miocene. In H. Kuhnet al. (eds). Contributions to Primatology Basel, S. Karger, 5: 62–103.
Andrews P. J. & Walker A., 1976.The Primate and other fauna from Fort Ternan, Kenya. In G. Isaac & E. McCown (eds). Human Origins: Louis Leakey and the East African Evidence Menlo, Univ. California Press: 279–304.
Ashton E. H. &Zuckerman S., 1950.Some quantitative dental characteristics of the chimpazee, gorilla and orangutan. Phil. Trans. R. Soc. London, 234 (B): 471–479.
Bonis L. de, & Melentis J., 1984.La position phyletique d’Ouranopithecus. In P. Andrews & J. Franzen (eds). The early evolution of man. Cour. Forsch. Inst. Senckenberg Frankfurt, 69: 13–23.
Bosler W., 1981.Species groupings of early Miocene Dryopithecine teeth from East Africa. Jl Human Evol., 10: 151–158.
Chesters K. I. M., 1957.The Miocene flora of Rusinga Island, Lake Victoria, Kenya. Palaeontographica, 101 (B): 30–67.
Day M., 1977.Guide to fossil man; A handbook of human palaeontology. London, Cassel, 3rd edition; 1–346.
Drake R., Van Couvering J. A., Pickford M. & Curtis G., in prep.K-Ar geochronology of early Miocene volcanic strata and associated vertebrate and early hominoid fossil localities: Rusinga and Mfwangano Islands, Uyoma Peninsula and Karungu-Western Kenya.
Fleagle J., Kay R. &Simons E. L., 1980.Sexual dimorphism in early anthropoids. Nature, 287: 328–330.
Frisch J., 1963.Sexual dimorphism in canines of Hylobates lar. Primates, 4: 1–10.
Garn S. M., Lewis A. B., Swindler D. R. &Kerewsky R. S., 1967.Genetic control of sexual dimorphism in tooth size. Jl. Dental Res., 46: 963–973.
Gingerich P. D., 1972.Correlation of tooth size and body size in living hominoid primates, with a note on relative brain size in Aegyptopithecus and Proconsul. Amer. Jl. Phys. Anthropol., 47: 395–398.
Greenfield L. O., 1972.Sexual dimorphisms in Dryopithecus africanus. Primates. 13: 395–410.
Greenfield L. O., 1973.Note on the placement of the most complete Kenyapithecus africanus mandible. Folia Primat, 20: 274–279.
Greenfield L. O., 1978.On the dental arcade reconstructions of Ramapithecus. Jl. Human. Evol., 7: 345–359.
Greenfield L. O., 1979.On the adaptive pattern of Ramapithecus. Am. Jl. Phys. Anthropol., 50: 527–548.
Harrison T., 1982.Small-bodied apes from the Miocene of East Africa. PhD Thesis. Univ. London: 1–647.
Hopwood A. T., 1933.Miocene primates from British East Africa. Zool. Jl. Linn. Soc., 38: 437–464.
Kay R. F., 1982.Sexual dimorphism in Ramapithecinae. Proc. Nat. Acad. Sci., 79: 209–212.
Keith A., 1932.Africa. Man, 32: 208.
Kent P. E., 1944.The Miocene beds of Kavirondo, Kenya. Quart. Jl. Geol. Soc. London, 100: 85–118.
Leakey L. S. B., 1962.A new lower Pliocene fossil primate from Kenya. Ann. Mag. Nat. Hist., 13: 689–696.
Leakey L. S. B., 1967.An early Miocene member of Hominidae. Nature, 213: 155–163.
Leakey L. S. B., 1968.Lower dentition of Kenyapithecus africanus. Nature, 217: 827–830.
Le Gros Clark W. E. &Leakey L. S. B., 1950.Diagnosis of East African Miocene Hominoidea. Quart. Jl. Geol. Soc. London, 105: 260–262.
Le Gros Clark W. E. &Leakey L. S. B., 1951.The Miocene Hominoidea of East Africa. Foss. Mamm. Afr., 1: 1–117.
Leutenegger W., 1970.Das Becken der rezenten Primaten. Gegenbaurs morph. Jb., 115: 1–101.
Leutenegger W., 1972.Beziehungen zwischen der Neugeborenengrosse und dem sexualdimorphism am becken bei simischen Primaten. Folia Primat., 12: 224–235.
Leutenegger W., 1978.Scaling of sexual dimorphism in body size and breeding system in primates. Nature, 272: 610–611.
Leutenegger W. &Kelly J. T.: 1977.Relationships of sexual dimorphism in canine size and body size to social, behavioural and ecological correlates in anthropoid primates. Primates, 18: 117–136.
Lucas P. W., 1982.An analysis of the canine tooth size of Old World higher Primates in relation to mandibular length and body weight. Archs Oral Biol., 27: 493–496.
MacInnes D. G., 1943.Notes on the East African Miocene Primates. Jl. E. Afr. Uganda Nat. Hist. Soc., 17: 141–181.
McLaughlin S. M. &Bruce M. F., 1984.Sex determination from the pelvis of dutch skeletal series. Proc. Anat. Soc. Gr. Brit. Ireland, Dec. 1984: 32.
Martin L., 1981.New specimens of Proconsul from Koru, Kenya. Jl. Human Evol., 10: 139–150.
Mobb J. &Wood B., 1977.Allometry and sexual dimorphism in the primate innominate bone. Amer. Jl. Anat., 150: 531–538.
Napier J. & Napier P., 1985.The natural history of the primates. London, Br. Mus. (Nat. Hist.): 1–200.
Oxnard C. E., 1983.Sexual dimorphisms in the overall proportions of primates. Amer. Jl. Primatol., 4: 1–22.
Pickford M., 1981.Preliminary Miocene mammalian biostratigraphy for Western Kenya. Jl. Human Evol., 10: 73–97.
Pickford M., 1983.Sequence and environments of lower and middle Miocene hominoids in Western Kenya. In Ciochon R. & Corruccini R. (eds.). New interpretations of ape and human ancestry. New York, Plenum: 421–439.
Pickford M., 1985.A new look at Kenyapithecus based on recent discoveries in Western Kenya. Jl. Human Evol., 14: 113–143.
Pilbeam D., 1969.Tertiary Pongidae of East Africa: Evolutionary relationships and taxonomy. Bull. Peabody Mus. Nat. Hist., 31: 1–185.
Remane A., 1965.Die Geschichte der Menschaffen. In Menschliche Abstammungslehre. Stuttgart, Gustav Fischer Verlag: 249–309.
Schultz A., 1963.Age changes, sex differences and variability as factors in the classification of primates. In S. Tax (ed.). Classification and Human Evolution. Viking Fund. Publ. Anthropol., 37: 85–115.
Schultz A., 1969.The life of Primates. New York, Universe Books.
Simons E. L. &Pilbeam D. R., 1965.Preliminary revision of the Dryopithecinae (Pongidae, Anthropoidea). Folia Primatol, 3: 81–152.
Verdcourt B., 1963.The Miocene non-marine Mollusca of Rusinga Island, Lake Victoria and other localities in Kenya. Palaeontographica, 121A: 1–37.
Walker A. &Pickford M., 1983.New postcranial fossils of Proconsul africanus and Proconsul nyanzae. In Ciochon R. & Corruccini R. (eds.). New interpretations of ape and human ancestry. New York, Plenum: 325–351.
Whitworth T., 1958.Miocene ruminants of East Africa. Foss. Mamm. Afr., 15: 1–50.
Wu R. &Oxnard C. E., 1983.Ramapithecines from China: evidence from dimensions of teeth. Nature, 306: 258–260.
Wu R. &Oxnard C. E., 1983.Ramapithecus and Sivapithecus from China: some implication for higher primate evolution. Amer. Jl. Primatol, 5: 303–344.
Zwell M., 1972.On the supposed Kenyapithecus africanus mandible. Nature, 240: 236–239.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Pickford, M. Sexual dimorphism in proconsul. Hum. Evol. 1, 111–148 (1986). https://doi.org/10.1007/BF02437490
Issue Date:
DOI: https://doi.org/10.1007/BF02437490