Evolutionary Divergence and Convergence in Shape and Size Within African Antelope Proximal Phalanges

Three-dimensional geometric morphometric analyses of humerus ecomorphology: New perspectives for paleohabitat reconstruction in carnivorans and ungulates

Long bone ecomorphology has proven effective for paleohabitat reconstructions across a wide range of mammalian clades. Still, there is no comprehensive framework to allow interpretation of long bone morphological variation within and between different monophyletic groups. Here, we investigated the use of humerus morphometry to classify living members of the orders Carnivora and ungulates based on their preferred habitats. Using geometric morphometrics, we extracted three different kinds of humerus shape data describing interspecific variation with and without accounting for evolutionary allometry and phylogenetic signal. The traditional a priori categorization of species in open, mixed, and closed habitats was employed in combination with selected subsets of shape variables to identify the best-predictive models for habitat adaptation. These were identified based on the statistical performance of phylogenetic and non-phylogenetic discriminant analyses and then applied to predict habitats on a subsample of fossil species. Size-free shape data combined with phylogenetic discriminant analyses showed the highest rate of accuracy in habitat classification for a combined sample of carnivorans and ungulates. Conversely, when the two groups were investigated separately, traditional shape data analyzed with phylogenetic discriminant function analyses provided models with the greatest predictive power. By combining carnivorans and ungulates within the same methodological framework we identified common adaptive features in closed habitat-adapted species that show compressed epiphyses, while open habitat-adapted species have expanded epiphyses. These morphologies evolved to allow significant degree of direction switches during locomotion in closed habitats compared to open habitat-adapted species whose forelimb joints evolved to stabilize articulations for increasing speed.

Occurrence and Progression of Dental Abnormalities in the Black Fronted Duiker (Cephalophus niger) Due to Deficient Diet and Extreme Weather Phenomena

This study aims to assess the contributory and predisposing effects of prolonged drought and climate phenomena on the occurrence of dental abnormalities among three age groups of the black duiker (Cephalophus niger). 36 skulls comprised of 18 females and 18 males were examined. Each group consisted of 8 kids (age range 0-10 months) (4 males and 4 females), 14 mature individuals (age range 1-3 years) (7 males and 7 females) and 14 adults (age range older than 3½ years) (7 males and 7 females). It was observed that the most severe defects occurred in mature and old females during prolonged drought. Morphologic disruptions of the dentition occurred more frequently on the mandible relative to the maxilla. 93% showed apical dental aberration. Bone resorption occurred in 30% and 6% of females and males respectively with profile aberrations at both time stages, tooth staining was observed in 40% of females and 8% of males, attrition accounted for 15% in each of both sexes, 28% and 3% of the females and the males had missing teeth respectively with more occurrence in the premolars and the molar teeth. Calculus was found in 4% and 9% of the females and males respectively. These findings may be useful in determination of likely age and season for occurrence of dental pathologies, in evaluation of response to irrigation and may provide information to assist in bioremediation of dental pathology.

Exploring morphological generality in the Old World monkey postcranium using an ecomorphological framework

Nearly all primates are ecologically dependent on trees, but they are nonetheless found in an enormous range of habitats, from highly xeric environments to dense rainforest. Most primates have a relatively 'generalised' skeleton, enabling locomotor flexibility and facilitating other crucial functions, such as manual foraging and grooming. This paper explores the associations between habitat, locomotion and morphology in the forelimbs of cercopithecids (Old World monkeys), contextualising their skeletal ecomorphological patterns with those of other mammals, and complementing functional morphological analyses with phylogenetic comparative techniques. The ecomorphological signals present in the generalised primate postcranium, and how an ancestral arboreal 'bauplan' might be modified to incorporate terrestriality or exploit distinct arboreal substrates, are investigated. Analysis of ecomorphological variation in guenons indicates that terrestrial Chlorocebus species retain core elements of a general guenon form, with modifications for terrestriality that vary by species. Adaptation to different modes of arboreality has also occurred in Cercopithecus. The considerable morphological similarity in the guenons sampled emphasises the importance of generality in the primate postcranium - much forelimb variation appears to have emerged stochastically, with a smaller number of traits having a strong functional signal. Analysis of a broader sample of cercopithecids and comparison with felids, suids and bovids indicates that although the cercopithecid humerus has functional morphological signals that enable specimens to be assigned with a reasonable degree of certainty to habitat groups, there is considerable overlap in the specimens assigned to each habitat group. This probably reflects ecological dependence on trees, even in predominantly terrestrial species, as well as the multiple functions of the forelimb and, in some cases, wide geographic distributions that promote intraspecific variation. The use of phylogenetic correction reduced the discriminatory power of the models, indicating that, like allometry, phylogeny contains important ecomorphological information, and should not necessarily be factored out of analyses.