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)

Abstract

ABSTRACT. Could studying of a single bones 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 bones 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 speciesspecific 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.KEY WORDS: mid-facial ontogeny, Old World monkeys, geometric morphometrics. Ìîäóëüíîñòü è èíòåãðàöèÿ â îíòîãåíåçå ñðåäíåé ÷àñòè ëèöåâîãî ñêåëåòà ó äâóõ âèäîâ çàïàäíîàôðèêàíñêèõ îáåçüÿí: êðàñíîãîëîâîãî ìàíãîáåÿ (Cercocebus torquatus) è çåëåíîãî êîëîáóñà (Procolobus verus) À.À. Åâòååâ, Î.Ã. Íàíîâà ÐÅÇÞÌÅ: Ìîaeåò ëè èçó÷åíèå ìîðôîëîãè÷åñêîé âàðèàöèè è ðîñòîâûõ ïðîöåññîâ îòäåëüíî âçÿòîé êîñòè äàòü êàêóþ-òî äîïîëíèòåëüíóþ èíôîðìàöèþ?  ïîèñêàõ ðåøåíèÿ ýòîãî âîïðîñà ìû îöèôðî-âàëè ñ ïîìîùüþ òðåõìåðíîãî äèãèòàéçåðà Microscribe êîíôèãóðàöèþ èç 13 òî÷åê, ðàñïîëîaeåííûõ â ñðåäíåé ÷àñòè âåðõíåãî ëèöåâîãî ñêåëåòà íà 25 ÷åðåïàõ Cercocebus torquatus è 16 ÷åðåïàõ Procolobus verus ðàçëè÷íîãî ïîëà è âîçðàñòà. Íàøè ðåçóëüòàòû ñâèäåòåëüñòâóþò, ÷òî, íåñìîòðÿ íà ñèëüíî âûðàaeåííóþ îíòîãåíåòè÷åñêóþ èíòåãðàöèþ â ïîñòíàòàëüíîì ðîñòå ëèöåâîãî ñêåëåòà ïðè-ìàòîâ, èçó÷åíèå ðîñòà îòäåëüíî âçÿòûõ êîñòåé ìîaeåò äàòü íåìàëî öåííîé ñ áèîëîãè÷åñêîé òî÷êè çðåíèÿ èíôîðìàöèè. Óäëèíåíèå ìîðäû çàìåòíî ñèëüíåå âûðàaeåíî ó C. torquatus è ñâÿçàíî îíî èìåííî ñ ðîñòîâûìè ïðîöåññàìè âåðõíå÷åëþñòíîé êîñòè. Ýòîò ïðîöåññ ìîaeåò áûòü óñïåøíî îïèñàí ñ ïîìîùüþ ìîäåëè ëèíåéíîãî ðîñòà è, ïî âñåé âèäèìîñòè, òåñíî ñâÿçàí ñ îáùèìè ñîìàòè÷åñ-êèìè ðîñòîâûìè ïðîöåññàìè. Îí, âèäèìî, íå èìååò íåïîñðåäñòâåííîãî àäàïòèâíîãî çíà÷åíèÿ, òàê êàê óäëèíåíèå ìîðäû ìîaeåò ïðèâåñòè ê ñíèaeåíèþ ñèëû óêóñà ðåçöîâ. Ðîñò ïðåä÷åëþñòíîé êîñòè â çíà÷èòåëüíîé ìåðå íåçàâèñèì îò ðîñòà ìàêñèëëû. Íèaeíÿÿ ÷àñòü ýòîé êîñòè ïðèíè...

Midfacial growth patterns in males from newborn to 5 years old based on computed tomography

“…Also, due to their limited functional role, the nasal bones could be less constrained in their growth and thus more variable. Similarly high variability in nasal bone shape is observed in many primate species (Evteev & Nanova, ; Schultz, ). It is unlikely that such increased variance is due to methodological issues since simotic dimensions exhibit a low level of intraobserver error (see Table ).…”