Search

This study provides preliminary data on the positional behavior and habitat use of the Philippine tarsier,Tarsius syrichta, which was studied in its natural habitat on the island of Leyte. The locomotor behavior ofT. syrichtais quite comparable to the other species of tarsiers but frequency of use of different postures and support types does seem to distinguish this species from the others.Tarsius bancanusappears to be the most specialized, using vertical clinging postures the most frequently and sitting the least;Tarsius dianaeuses vertical clinging the least frequently and sitting the most, andT. syrichtais intermediate. The Philippine tarsier has a small home range similar to that ofT. spectrum. On the other hand, this species likely does not have the small family groups typical of Sulawesi tarsiers but instead uses a noyau system likeT. bancanus. This data supports some apsects ofNiemitz’s (1977) model of anatomical and behavioral specialization among tarsier species.

Locomotor diversity of Eocene primates of North America and Europe was well developed, with species of both Adapidae and Omomyidae showing a wide spectrum of movements. Besides documenting the locomotor diversity in the Eocene, this paper shows that adapid foot morphology shares derived features with extant strepsirhines. Thus, the Omomyidae best resemble the ancestral euprimate in terms of foot morphology and locomotion. The generalized locomotor repertoire of the modern cheirogaleids represents the best model for the movement pattern of the ancestral euprimate.

The locomotor pattern of the ancestral lorisid is of particular interest since extant galagines and lorisines contrast dramatically in their movements. The foot bones of three lorisid species are known from the early Miocene of Kenya and a new talus from Koru is described in this paper. The movement patterns of the early Miocene lorisids from Kenya are most similar to the more generalized movements of the cheirogaleids, which often move by quadrupedalism, leaping, climbing and suspension. The foot evidence indicates that lorisines have evolved from a leaping ancestry before they adopted their slow-climbing mode of travel and that the talus from Koru and the calcaneus attributed to Komba robustus exhibit lorisine-like features.

One of the most controversial issues in primate palaeontology concerns the phylogenetic position of the extinct primate inf raorder Adapiformes1,2. During the Eocene, this group of primates of modern aspect possessed a holarctic distribution1–12, and may have been present in the poorly known Palaeogene of Africa10. Mainly on the basis of craniodental morphology, at least four hypotheses have been proposed concerning the phylogenetic interrelationships among adapiforms and other primate higher taxa: (1) that adapiforms are ancestral to both lemuriforms (including Lorisoidea) and anthropoids8–10'13; (2) that adapiforms cannot be shown to possess a special phylogenetic relationship with either lemuriforms14'15or anthropoids15−18; (3) that adapiforms are the sister taxon of lemuriforms16–18; and (4) that Adapiformes is not a natural, monophyletic group, but rather consists of nested clades within the radiation of lemuriforms19–25. Here, we describe features of the ankle and wrist joints of several adapiform taxa that provide an independent test of the preceding hypotheses. These traits suggest that lemuriforms are monophyletic with respect to known adapiforms, but that adapiforms nevertheless are their stem lineage (sensu Ax26).