Leonard Freedman

South African fossil Cercopithecoidea: A re-assessment including a description of new material from Makapansgat, Sterkfontein and Taung

Abstract The fossil cercopithecoid material from South Africa has been reviewed according to sites and species. The 722 specimens considered comprise 6 genera including 16 taxa and come from 16 sites. Aspects of taxonomic controversy and interest are discussed. In particular, the Parapapio material from Makapansgat has been re-evaluated and the taxonomy of the genus Simopithecus is reconsidered. A number of proposals are put forward. Four new specimens from Makapansgat and one from Sterkfontein are described; a previously partially described specimen from Taung is re-described in detail.

Some aspects of pongid and hominid bipedality

Abstract Differences in the efficiency of living pongids and man as bipeds are discussed in terms of: (1) influences of the position of the centre of gravity on the torque levels produced at the hip and knee joints and the adaptations necessary to cope with these; (2) the nature of the specialization of the propulsive mechanism of the lower limb—for power in pongids but for speed and energy conservation in Man; and (3) the effectiveness of lateral balance control, especially during locomotion. It is suggested that the difference in bipedal efficiency of pongids and hominids does not depend on a single major difference, such as a major charge in the function of gluteus maximus, but rather on a series of more subtle differences which together have profound consequences. The evolution of erect bipedality appears to have occurred in two phases, the first of which was primarily concerned with re-positioning the centre of gravity to reduce the energy cost of frequent use of bipedality, and the second concerned the development of a speed-oriented striding and running mechanism.

Human skeletal remains from Cossack, Western Australia

Abstract Human remains of a male individual from Cossack, northwestern Australia are described. Absolute dating is not possible but site geomorphology restricts the upper limit to 6500 B.P. Morphologically and metrically the skull differs from those of recent Western Australian male Aborigines, but it is very similar to that of Kow Swamp I and others included in the “robust” prehistoric Australian Aboriginal group ( Thorne, 1977 ). The specimen is important as indicating the widespread nature and probable recency of a large, robust Australian Aboriginal population demonstrably different to recent populations.

Discrete trait variation in Western Australian Aboriginal skulls

The non-metrical features of 125 Western Australian Aboriginal skulls in four regional samples have been analysed. An analysis of variance revealed significant differences in the trait frequencies between the sexes. The data for males and females were analysed separately by a modified Grewal-Smith technique (Green et al., 1979) . The relationships between the samples were similar for both sexes. The inland sample (east) was shown to diverge greatly from the three coastal samples (north, central and south). On the basis of the sizes of the standard deviations of the divergences for each trait in the six pairwise comparisons, the number of traits was reduced to 16 for males and 20 for females. The reduction did not alter the relationships found. Extending the analysis to include samples from coastal New South Wales and Queensland (adapted from Larnach and Macintosh, 1966 , Larnach and Macintosh, 1970 again showed east to be the most divergent of the Western Australian samples. The east sample also showed the greatest divergences from New South Wales and Queensland, between which the divergences were very small. These and other inter-relationships essentially support the craniometric and odontometric studies of similar samples by Margetts & Freedman (1977) and Freedman & Lofgren (1981) .

Dental sexual dimorphism and morphology in african colobus monkeys as related to diet

We considered the relationship between dental sexual dimorphism and diet in 542 specimens of olive, red, and black-and-white colobus. Using univariate statistical techniques, we examined 41 measurements of the maxillary and mandibular dentitions. The results reveal two trends of dental sexual dimorphism in black-and-white colobus wherein (i) maleColobus guereza andC. angolensis are generally larger than females throughout the dentition and (ii)C. satanas and, to a lesser degree,C. polykomos exhibit reduced sexual differences in the canine base and females are slightly larger than males in noncanine dimensions. Females of the red colobus,Procolobus (Piliocolobus) badius, are slightly larger than males in most noncanine measurements but canine sex differences are more pronounced than those of black-and-white colobus.Procolobus (Procolobus) verus, the olive colobus, is characterized by some of the largest canine sex differences, yet the sexes do not differ much in noncanine mean values. When patterns of sexual dimorphism are considered in terms of specific ecology and behavior, it is possible to relate sex differences, in part, to known dietary differences. For example, overall dental morphology and the trend of sexual differences inC. satanas andC. polykomos seem to be associated with the consumption of a diet rich in seeds. The pattern of dental sexual dimorphism inC. badius may also be influenced by dietary factors in that their patrilineal social organization could restrict female access to certain foods thereby affecting rates of attrition and creating selection pressure for larger teeth. Relatively less is known of the ecology and social organization ofP. verus but their dental sexual dimorphism is possibly less related to dietary factors than is the case for red or black-and-white colobus.

The differential use of cheek pouches in a troop ofPapio ursinus

Cheek pouches, one of the distinguishing characters of the Cercopithecinae, are structures used for the temporary storage of food. Their size and frequency of use within a given species are related primarily to the amount of conspecific competition for food. In relation to total body size, members of the genusPapio are considered to have relatively small cheek pouches which are said to be used only occasionally to maximize food harvest when local clusters of food are encountered.This investigation represents 165 hours of observation on a troop ofPapio ursinus at Mkuzi Game Reserve in Natal, South Africa. At the time of observation the choice of foods in the home range was restricted and usually found in abundance only in small clusters of trees. Given that conspecific competition would have been pronounced under these conditions, it was thought that any differences in the frequency of cheek pouch use related to age, sex, rank, or the reproductive state of an animal would be readily recognizable.The results indicated that cheek pouches were used differentially throughout the day, with virtually all ages of each sex displaying the same general pattern of maximal cheek pouch use during the middle of the day. In each sex there was an age graded diminution of the frequency of cheek pouch use from juveniles to adults. This trend was more pronounced in males resulting in a substantial sex difference in the use of cheek pouches between adult males and females. In addition, there was some indication that differences in the frequency of cheek pouch use between adult males were correlated with rank. Although a pattern of cheek pouch use and rank was not evident amongst adult females, there was an association between reproductive state and the frequency of cheek pouch use. Overall, body size, dominance, and energetic demands appeared to be the most significant factors underlying the differences in cheek pouch use in this troop.

Morphometric analysis of Macaca arctoides and M-thibetana in relation to other macaque species

As a first step in reviewing the classification of the two stump-tailed macaque species,Macaca arctoides andM. thibetana, as compared with other species of the genusMacaca, 72 linear dental and cranial variables of 11 macaque species were examined by morphometric analyses. The results indicate that the two stump-tailed species are the largest of the macaques and although rather similar overall, they exhibit significant differences in the pattern of variation in most of the five skull regions as shown by Principal Components and Canonical Variate Analyses. Euclidean Distances based on Canonical Variate scores indicate that the females ofM. arctoides andM. thibetana are more widely separated than eight other pairs of macaque species, and that the separations of the respective males are greater than those of three other pairs of species. These findings are consistent withFoodens classification of the stump-tailed macaques as two separate species (Fooden, 1976;Fooden et al., 1985). The present results suggest, as other researchers have proposed on the basis of external features, biochemistry and genetics, that the two stump-tailed macaque species andM. assamensis are closely related. The results also tentatively imply associations withM. fuscata andM. sylvanus but these require further study. The findings have implications for the assessment of the various Chinese Pleistocene macaque fossils.

The differential expression of dental sexual dimorphism in subspecies ofColobus guereza

Data on dental sex differences in seven of the eight currently recognized subspecies of Colobus guerezareveals a range of expression of sexual dimorphism. Males of most subspecies are larger than females throughout the dentition and this is especially pronounced for the canines and P3For C. g. guerezaand C. g. gallarum,however, sex differences in the canines and P3are less pronounced and females are often slightly larger than males in noncanine dental measurements. C. guerezasspp. occupying comparable habitats express similarities in the degree of maxillary canine dimorphism. In addition, for those subspecies distributed above the equator, there is also a cline of decreasing maxillary canine dimorphism from west to east in a progressively more northern direction. This cline corresponds to the occupation of increasingly more arid habitats, and reduced dimorphism is the result of larger maxillary canine size in females. We propose that this pattern of sexual dimorphism is related to differences in the relative intensity of predation pressure, guereza social organization, and energetic considerations. That the mandibular canine does not exhibit a similar trend of sexual dimorphism suggests that larger maxillary canines in females may function as weapons.

Odontometric variation among local populations of Kenyan olive baboons

Abstract This is a first report on a survey of local variations in genetic marker frequencies and morphometric features on Kenyan olive baboons. Data on dental casts of the upper dentitions of 207 baboons (115 males and 92 females) are analyzed with univariate and multivariate techniques. The materials represent 18 troops captured at 4 different localities. In general, levels of variability within and between localities are not great. The most marked variations present are in the premolar teeth. Females show greater variation than males. There are suggestive correlations between morphometric distance and geographic distance (positive) and morphometric distance and altitude difference (negative). There are some differences between this olive baboon sample and that of Swindler, McCoy & Hornbeck (1967) which lies close to a zone of olive-yellow baboon hybridization (Maples, 1972) .

A comment on Dayal et al. (2008) assessment of sex using the skull

D. Franklin , L. Freedman, P. O’Higgins, C.E. Oxnard Centre for Forensic Science, The University of Western Australia, 35 Stirling Hwy, Crawley, Western Australia, Australia School of Anatomy and Human Biology, The University of Western Australia, 35 Stirling Hwy, Crawley, Western Australia, Australia Functional Morphology and Evolution Research Unit, The Hull York Medical School, Heslington, York Y010 5DD, UK