The phyletic link of living tarsiers to fossil primates has been a difficult bridge to cross. Although Tarsiidae has been linked to fossil tarsiiforms such as omomyids and microchoerids, as well as to anthropoids, no consensus of opinion has been reached. Here we add several new postcranial elements for one of the most primitive of all tarsiiforms, Teilhardina belgica from Dormaal, Belgium. We compare this new material to that of living and fossil tarsiers as well as to other Eocene fossil primates. Besides the previously known tarsals for Teilhardina, we have been able to add a distal humerus, a proximal ulna, a second metacarpal, a proximal and a distal femur, tibiae, additional tarsals, first metatarsals, and several proximal and middle phalanges. Although most of these postcranial elements compare best with other omomyids, and therefore do not resolve the phyletic relationship of omomyids relative to tarsiers, the fingers and toes of Teilhardina are quite elongated, a similarity to living tarsiers. Middle phalangeal lengths of the diminuitive Teilhardina are comparable in length to much larger species of Tarsius suggesting relatively even longer digits. The digit features of Teilhardina and Tarsius are unusual for primates in general and may in fact represent an ancestral state although hands and feet of other fossil tarsiiforms are needed to test this hypothesis.
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Ants, the most abundant taxa among canopy-dwelling animals in tropical rainforests, are mostly represented by territorially-dominant arboreal ants (TDAs) whose territories are distributed in a mosaic pattern (arboreal ant mosaics). Large TDA colonies regulate insect herbivores, with implications for forestry and agronomy. What generates these mosaics in vegetal formations, which are dynamic, still needs to be better understood. So, from empirical research based on three Cameroonian tree species (Lophira alata, Ochnaceae; Anthocleista vogelii, Gentianaceae; and Barteria fistulosa, Passifloraceae), we used the Self-Organizing Map (SOM, neural network) to illustrate the succession of TDAs as their host trees grow and age. The SOM separated the trees by species and by size for L. alata, which can reach 60 m in height and live several centuries. An ontogenic succession of TDAs from sapling to mature trees is shown, and some ecological traits are highlighted for certain TDAs. Also, because the SOM permits the analysis of data with many zeroes with no effect of outliers on the overall scatterplot distributions, we obtained ecological information on rare species. Finally, the SOM permitted us to show that functional groups cannot be selected at the genus level as congeneric species can have very different ecological niches, something particularly true for Crematogaster spp. which include a species specifically associated with B. fistulosa, non-dominant species and TDAs. Therefore, the SOM permitted the complex relationships between TDAs and their growing host trees to be analyzed, while also providing new information on the ecological traits of the ant species involved. This article is protected by copyright. All rights reserved.
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