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- All Subjects: Cercopithecidae
- Creators: Reed, Kaye E
Description
Cercopithecid primates today occupy the greatest geographic and climatic range of any non-human primate group. Pliocene and Pleistocene cercopithecids are often found together in fossil deposits across East and South Africa, raising the question of how these species co-occurred with one another and survived in increasingly arid and seasonal environments. Aspects of shearing ability, molar enamel thickness, and relative incisor, premolar, and molar proportions were analyzed in principal component analysis and used to generate six potential models of the cercopithecid dental morphological niche. Resulting principal component axes distinguish between taxa with varying proportions of leaves, fruit, insects, and seeds in the diet, but lose some clarity when variable subsets are used that exclude poorly-preserved or wear-restricted variables. Resampling was used to reconstruct the aggregate dental morphological niches of cercopithecid communities (taxocenes) from Africa and Asia today and from the African Pliocene and Pleistocene. Modern Asian cercopithecid taxocenes occupy a more restricted niche than their counterparts in Africa, but in both regions variation in taxocene structure is linked with past and current climate factors related to precipitation, temperature, and seasonality. Fossil cercopithecids from the Turkana Basin occupy an expanded niche in comparison to modern African and Asian taxocenes. In contrast, South African fossil taxocenes occupy a more distinct and restricted niche, which may reflect a mix of paleoenvironmental and taphonomic factors. Overall these results are consistent with existing research on modern African and Asian primate taxocene diversity and highlight the utility of a dental metric model for examining community evolution among Plio-Pleistocene cercopithecids in Africa. Evidence for a possible niche expansion during the early Pleistocene coincides with a period of well-documented hominin co-occurrence at the same fossil sites, suggesting that these two primate groups were diversifying in response to shared environmental stimuli.
ContributorsSmail, Irene (Author) / Reed, Kaye E (Thesis advisor) / Campisano, Christopher J (Committee member) / Gilbert, Christopher C (Committee member) / Arizona State University (Publisher)
Created2021
Description
Dietary diversity is an important component of species’s ecology that often relates to species’s abundance and geographic distribution. Additionally, dietary diversity is involved in many hypotheses regarding the geographic distribution and evolutionary fate of fossil primates. However, in taxa such as primates with relatively generalized morphology and diets, a method for approximating dietary diversity in fossil species is lacking.
One method that has shown promise in approximating dietary diversity is dental microwear analyses. Dental microwear variance has been used to infer dietary variation in fossil species, but a strong link between variation in microwear and variation in diet is lacking. This dissertation presents data testing the hypotheses that species with greater variation in dental microwear textures have greater annual, seasonal, or monthly dietary diversity.
Dental microwear texture scans were collected from Phase II facets of first and second molars from 309 museum specimens of eight species of extant African Old World monkeys (Cercopithecidae; n = 9 to 74) with differing dietary diversity. Dietary diversity was calculated based on food category consumption frequency at study sites of wild populations. Variation in the individual microwear variables complexity (Asfc) and scale of maximum complexity (Smc) distinguished groups that were consistent with differences in annual dietary diversity, but other variables did not distinguish such groups. The overall variance in microwear variables for each species in this sample was also significantly correlated with the species’s annual dietary diversity. However, the overall variance in microwear variables was more strongly correlated with annual frequencies of fruit and foliage consumption. Although some variation due to seasonal and geographic differences among individuals was present, this variation was small in comparison to the variation among species. Finally, no association was found between short-term monthly dietary variation and variation in microwear textures.
These results suggest that greater variation in microwear textures is correlated with greater annual dietary diversity in Cercopithecidae, but that variation may be more closely related to the frequencies of fruit and foliage in the diet.
One method that has shown promise in approximating dietary diversity is dental microwear analyses. Dental microwear variance has been used to infer dietary variation in fossil species, but a strong link between variation in microwear and variation in diet is lacking. This dissertation presents data testing the hypotheses that species with greater variation in dental microwear textures have greater annual, seasonal, or monthly dietary diversity.
Dental microwear texture scans were collected from Phase II facets of first and second molars from 309 museum specimens of eight species of extant African Old World monkeys (Cercopithecidae; n = 9 to 74) with differing dietary diversity. Dietary diversity was calculated based on food category consumption frequency at study sites of wild populations. Variation in the individual microwear variables complexity (Asfc) and scale of maximum complexity (Smc) distinguished groups that were consistent with differences in annual dietary diversity, but other variables did not distinguish such groups. The overall variance in microwear variables for each species in this sample was also significantly correlated with the species’s annual dietary diversity. However, the overall variance in microwear variables was more strongly correlated with annual frequencies of fruit and foliage consumption. Although some variation due to seasonal and geographic differences among individuals was present, this variation was small in comparison to the variation among species. Finally, no association was found between short-term monthly dietary variation and variation in microwear textures.
These results suggest that greater variation in microwear textures is correlated with greater annual dietary diversity in Cercopithecidae, but that variation may be more closely related to the frequencies of fruit and foliage in the diet.
ContributorsShapiro, Amy Elissa (Author) / Reed, Kaye E (Thesis advisor) / Schwartz, Gary T (Committee member) / Ungar, Peter S. (Committee member) / Arizona State University (Publisher)
Created2015