摘要:

Recognized species of sakis, South American monkeys of genus Pithecia (Cebidae), are P. hirsuta Spix, P. monachus E. Geoffroy, P. albicans Gray, P. pithecia Linnaeus. Evolutionary stages in sexual dichromatism in sakis and other primates are noted.

ISSN:0015-5713    

DOI:10.1159/000155871

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

Ontogenetic investigations confirm that independent entotympanics are absent in living primates. Although cartilage occurs in the petrosal tympanic processes of some primates, the assumption that a suppressed entotympanic is thereby indicated can be adequately refuted according to embryological canons of interpretation. Problems regarding the homologies of different entotympanics, largely ignored by paleontologists and system-atists, reduce or negate their taxonomic valency for all but closely related groups. Until such puzzles are resolved, the possible but doubtful existence of entotympanics in plesiadapoids and inferred pre-primate ancestors cannot buttress claims for alleged ties between primates and certain entotympanic-bearing eutherians (principally bats, colugos and tree shrews).

ISSN:0015-5713    

DOI:10.1159/000155872

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

Three new genera and four new species of omomyid primates constitute the first record of the Primates from upland middle Eocene rocks of Wyoming. One of these, Strigorhysis, gen. nov., possesses broadly basined molars with highly crenulated enamel which probably indicates a good deal of tough vegetable matter in its diet. Each of the new genera could have descended from known Wasatchian or early middle Eocene anaptomorphines: Aycrossia, gen. nov., is a plausible derivative of Tetonius or Chlororhysis; Strigorhysis, gen. nov., is most simñar to Absarokius noctivagus; and Gazinius, gen. nov., most closely resembles Absarokius and Anaptomorphus. The anaptomorphines were probably equally as diverse as the better documented omomyines in the middle Eocene, but may have preferred upland environments at the margins of the Tertiary basins of the Rocky Mountain Interior

ISSN:0015-5713    

DOI:10.1159/000155873

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

The volumes of the main components of the diencephalon from 10 basal insectivores, 12 prosimians, and 15 simians including man were compared. The comparison of the percentage composition within the diencephalon shows that the thalamus and the subthalamus increase whereas the epithalamus and the hypothalamus decrease in relative size among primates. The allometric analysis reveals that, in spite of a relative reduction, the epithalamus and the hypothalamus are also progressive structures. However, their allometric size increase, being especially accentuated in earlier phyletic phases, is small in comparison to that of the thalamus and the subthalamus. These latter two components are characterized by a continuous phylogenetic growth from the basal insectivores to the simians. The correlation analysis shows that the strongest correlations and, in many cases, that isometric size increase exist between structures which belong to the same functional system.These findings indicate the existence of at least two major developmental gradients in the quantitative development of the diencephalon, a neencephalic and a limbic one.

ISSN:0015-5713    

DOI:10.1159/000155874

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

Several Lemur catta troops at Berenty, Madagascar have been censused repeatedly since 1963. In 1972, the entire reserve was censused. A recensus in 1975 showed that although some minor changes have occurred in the number of animals in individual troops, the population of the reserve as a whole, the core areas of the lemurs’ territories, and their home range boundaries have all remained stable ever since the first complete census 3 years earlie

ISSN:0015-5713    

DOI:10.1159/000155875

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

Observations of chimpanzees under naturalistic conditions show that nutritional autonomy increases as young individuals mature. Substantial proportions of feeding time are spent eating food obtained through solicitation. Food sharing at SOPF occurs among mother and infant pairs most frequently; less frequently between adult males and infants or juveniles, and least frequently between adult females and immature individuals. Mothers tend to share what their offspring cannot obtain independently while others primarily share what is easiest to replace. These patterns of solicitation and distribution of food are consistent with predictions based upon benefits to individuals through kin selection and/or energetic efficiency.

ISSN:0015-5713    

DOI:10.1159/000155876

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

A total of 15 months were spent on field research in eastern Madagascar studying the largest extant lemur Indri indri. Social relationships were analysed according to the frequency and direction of affiliative and agonistic behaviours, and with respect to the relative tree positions and behavioural synchrony of group members. The relationship between the adult male and adult female in each group was distinguished by the sub-ordinance of the former. Between group variation in adults’ relationships are examined with respect to the function of this behaviou

ISSN:0015-5713    

DOI:10.1159/000155877

出版商:S. Karger AG    

年代:1979

数据来源: Karger