A taxonomic and ecological study of the living and fossil hystricidae with particular reference to Southern Africa.

[摘要] The taxonomy of modern and fossil Hystricidae and the evolutionary historyof the family has been reviewed, with particular reference to 203 undescribedSouth African specimens from the Transvaal australopithecine depositsand Cave of Hearths. After comparison with all contemporaneous fossilforms (only 10 of the 28 described fossil species seem valid) it was concludedthat Xenohystrix crassidens Greenwood 1955, Hystrix makapanensis(Greenwood 1958) and H. africaeaustralis Peters 1852 are present at HakapansgatLimeworks, whereas only the latter species is present at theremaining australopithecine sites, with the possible exception of a fewtentatively referred specimens of H. makapanensis. There are insufficientgrounds for erecting a distinct species for the fossil form of H. africaeaustralispresent in the australopithecine deposits and the Cave of Hearthsmaterial is likewise referred to the modern species. The distribution andminimum numbers of individuals of porcupine species present in the differentbreccias of the five sites is detailed and a reconstruction of the skulland mandible of X. crassidens attempted. The environment, stratigraphyand potential ages of the source deposits is discussed; it is concludedthat with the exception of Taung, the dates suggested by Partridge andVrba agree with the limited evidence provided by the fossil Hystricidae.Numerous skull characters used in the diagnoses of new Hystrix were examinedfor variability within a single modern species (only 3 of the 77 extant speciesproved to be valid) and then tested for diagnostic significance bycomparison with the remaining valid species. Special attention was paidto mandibular and dental characters, particularly the crown enamel pattern,but the only reliable diagnostic characters were found to be associatedwith the anterior part of the cranium, which is seldom preserved in fossilform. The sequence of tooth replacement, a method for identifying isolatedteeth, methods for segregating specimens into growth stages, and a standardterminology have been outlined.A taphonomic study, attempting to determine the extent to which fossilporcupines may have been responsible for the accumulation of the MakapansgatLimeworks bone assemblage and for the manufacture of the bone toolsdescribed by Dart, was undertaken. Unlike the fossil assemblage porcupinebone accumulations are characterized by a high percentage of much-gnawedbones, a large average fragment size, a high proportion of intact shafts withthe concomitant near-absence of bone flakes anci a low survival potentialfor the articular ends of all limb bones. Comparison showed that thedamage done by porcupines differs from that evident on the correspondingskeletal elements from Makapansgat. It is concluded that fossilporcupines had very little to do with either the accumulation orfracture of the Makapansgat Limeworks bones.

[发布机构] University of the Witwatersrand