Survey of the black howler monkey,<Emphasis Type="Italic">Alouatta pigra</Emphasis>, population at the Mayan site of Palenque,Chiapas, Mexico

A survey of the population of the black howler monkey (Alouatta pigra) present at the Mayan site of Palenque was conducted during 2000. A total of 911 man/hours, spread over 112 days were spent surveying the 600 ha area of pristine forest at the site for howler troops. We detected the presence of 136 individuals of which 131 were members of 20 troops, the rest were 3 solitary adult males and 2 adult males travelling as a pair. Ecological density was estimated at 23 individuals/km². Mean troop size was 7.0 individuals and it ranged from 2–12 individuals; 60% of the troops were multimale. All sighting of howler monkeys were in evergreen rain forest and 75% were in trees ≥20 m in height. The reported densities and mean troop size are higher than those reported for the species in Guatemala and in central Quintana Roo, Mexico. The vegetation of the forest contains tree species reported to be used by species ofAlouatta in the Moraceae, Sapotaceae, Leguminosae, and Lauraceae plant families. Protection of a large perimeter area (ca 1700 ha) around the archeological site by the Mexican government ensures the conservation of the forest and of the black howler monkey population present at the site.     

A reassessment of the taxonomic status and phyletic relationships of Papio baringensis and Papio quadratirostris (Primates: Cercopithecidae)

Comparison of the skulls of Papio baringensis Leakey 1969 from the Chemeron Formation and P. quadratirostris Iwamoto 1982 from the Usno Formation with those of Theropithecus gelada, T. brumpti, T. darti, T. oswaldi, and several species of Papio indicate that the species from Chemeron and Usno exhibit all, or most, respectively, of the shared derived characters of Theropithecus. We propose that they be removed from Papio and placed in Theropithecus as T. baringensis and T. quadratirostris. Comparison of the specimens of T. baringensis and T. quadratirostris with those of T. brumpti indicate that the former two species have some of the derived characters of T. brumpti but are primitive in others. We propose that the three species form the following phyletic lineage: T. baringensis-T. quadratirostris-T. brumpti. With these referrals, there are now six species of the genus Theropithecus. Based on geologic grounds, the specimens from Chemeron are about 4.0 million years (m.y.), that from Usno between 3.3 and 3.4 m.y., and those of T. brumpti between 2.0 and 2.8 m.y. in age. We also show that the most complete specimen of Papio sp. nov. from Olduval Gorge belongs to T. oswaldi. With the removal of these specimens from Papio, the East African fossil record of this genus, apart from isolated teeth, comprises only 21 specimens, while that of Theropithecus comprises at least 300 specimens.     

Morphometric analysis of growth and development in wild-collected vervet monkeys (Cercopithecus aethiops), with implications for growth patterns in Old World monkeys, apes and humans

A study was undertaken of a unique sample of 63 wild vervet monkeys Cercopithecus aethiops from a single population in Uganda collected over 35 days in 1947. Twenty-five were immature (12 females and 13 males) and 38 were adults (16 females and 22 males). Body mass, external measurements, masticatory and other masses were recorded for each individual at the time of collection, and for a few specimens, the development of the reproductive organs. Each individual was evaluated for cranial capacity, limb length and dental eruption. The comparison of immature and adult animals illustrates the mosaic nature of growth in the different body systems, as well as female–male differences. An ancestral model is proposed for catarrhine growth and development, with particular reference to sex differences. This model provides a framework for assessment of immatures and for the reconstruction of socio-ecological effects on life-history stages in populations of fossil monkeys, apes and early hominids.     

Completeness of a fossil record: the Pleistocene echinoids of the Antilles

Diversity of Pleistocene marine invertebrates with single component, robust, easily identifiable skeletons shows a good correspondence to that of the Recent when compared between similar environments in the same region. Such comparisons are less easily made for multi-element skeletons. In the Antilles there are 24 extant species of echinoids in 0–30  m water depth. Considering all available fossils - complete tests, disarticulated spines, and test fragments and ossicles - the Pleistocene echinoids of the Antillean region have a high similarity with the extant shallow water fauna (c. 63% specific and 72% generic similarity). Many of the extant, shallow water, regular echinoid taxa are known from the Pleistocene, although irregular echinoids are less well represented. These results are comparable with those determined for coeval benthic invertebrates from this and other geographic regions, and indicate a high degree of similarity from a survey which is so far limited to only a few of the islands. Not all Pleistocene units considered herein were deposited in shallow water, but they include autochthonous specimens of taxa whose depth range extends beyond shallow water at the present day or presumed allochthonous specimens derived by downslope transport from shallower water, or both.     

Flower and Fruit Visitors of Marcgravia longifolia in Amazonian Peru

Abstract: We recorded nectarivorous and frugivorous visitors of Marcgravia longifolia (Marcgraviaceae) at the Estación Biológica Quebrada Blanco in the northeastern Peruvian Amazonia. M. longifolia belongs to the subgenus Plagiothalamium, with downward facing flowers. A glossophagine bat, probably Anoura caudifer, was identified as a potential pollinator. Three primate species - Saguinus fuscicollis, Saguinus mystax and Callicebus cupreus - were recorded as potential seed dispersers. This is the first documentation of primate seed dispersal of a species from the family Marcgraviaceae.     

Positional behavior and body size of arboreal primates: a theoretical framework for field studies and an illustration of its application.

The rationale for most field studies of the positional behavior of arboreal primates has been the need to document natural behaviors quantitatively in order to infer the functional significance of morphological configurations. This focus on interactions of morphology with behavior is justifiable, but there exists another important level of biological relationships, that of the animal with its structural habitat, which it must negotiate to find food and avoid being preyed on. Recently it has become apparent that body size is likely to affect relationships of positional behavior with habitat structure, as well as with morphology. Here I offer a framework for research on functional relationships of positional behavior, body size, and habitat structure, with the ultimate objective of elucidating the aptive significance of the great diversity exhibited by arboreal primates. This approach specifies several distinct problems that animals solve, and indicates how research might be directed at revealing the relative effectiveness with which different primates solve them. A preliminary application of the framework examines sympatric north Sumatran primates.     

Dental development in South African australopithecines. Part I: Problems of pattern and chronology

It is well known that humans take about twice as long as apes to mature. The traditional view that such delayed maturation was already present in australopithecines has been called into question during the past several years. We have approached this problem by looking at patterns of dental development in gracile and robust australopithecines from South Africa and comparing them to patterns found in extant humans and apes. We have employed both 2 and 3 dimensional computed tomography in our research. The dental growth patterns in these two australopithecine morphs differ, particularly in M1/I1 development. The robust australopithecines are more humanlike and the gracile australopithecines more apelike in this feature (“humanlike” and “apelike” are not used in any taxonomic sense). Pattern and chronology of dental development must be considered separately. Several major problem areas for future research are identified, most of which revolve around the issue of intra- versus interspecific variation.