Evteev A.A., Nanova O.G. 2013. Modularity and integration in ontogeny of the middle facial skeleton in two West African monkey species: collared mangabey (Cercocebus torquatus) and olive colobus (Procolobus verus) // Russian J. Theriol. Vol.12. No.1: 1–18 [in English].
Andrej A. Evteev [email@example.com], Anuchin’s Research Institute and Museum of Anthropology of the Moscow State University, Mokhovaya str. 11, Moscow 125009, Russia;
Olga G. Nanova [firstname.lastname@example.org], Zoological Museum of the Moscow State University, Bol’shaya Nikitskaya str. 5/7, Moscow 125009, Russia.
KEY WORDS: mid-facial ontogeny, Old World monkeys, geometric morphometrics.
ABSTRACT. Could studying of a single bone’s morphological variation and growth provide some additional information? For addressing this question a configuration of 13 landmarks from the middle part of the upper facial skeleton was digitized by Microscribe 3D digitizer on 25 skulls of Cercocebus torquatus and 16 skulls of Procolobus verus of different age and sex. Our results suggest that despite of strong ontogenetic integration in postnatal growth of the primate facial skeleton a study on a single bone’s growth could provide a lot of biologically meaningful information. Elongation of the snout is far more pronounced in C. torquatus and related specifically to growth of the maxilla. This process can be described by a linear growth model and seems to be closely related to the general somatic growth rather than be by itself adaptive since an elongated snout could decrease bite force generation capacity at the incisors. Premaxillary growth is to a substantial degree independent from maxillary growth. The lower part of the bone attains its species-specific shape early in ontogeny what can be considered as a preparation to strong masticatory loadings which begin in this species during the first year of life. Later growth processes of the two bones are closely related and as a result shape of the premaxilla is substantially modified. Proximal and distal parts of the nasal bones seem to show differences: the former could be apparently different among individuals of the same species while shape and size of the later much more reflect elongation of the maxilla during postnatal period.