Jungers W L, Fleagle J G
Am J Phys Anthropol. 1980 Nov;53(4):471-8. doi: 10.1002/ajpa.1330530403.
Cebus albifrons and Cebus apella, partially sympatric capuchin monkeys from South America, are known to differ substantially in adult body mass and bodily proportions. C. apella possesses a robust, stocky build in contrast to the more gracile, relatively longer limbed body design of C. alblfrons. Average birth weights and adult body lengths of these two congeners, however, are remarkably similar and do not serve to distinguish them. This study examines longitudinal growth rates and patterns of ontogenetic scaling in the extremities (humerus, radius, hand, femur, tibia, foot) in order to document the nature and magnitude of skeletal changes associated with increasing age and body mass. Our data indicate that the growth rates of the six skeletal components of the limbs differ only slightly and somewhat inconsistently between the two species. Body mass, however, increases at a consistently faster rate in C. apella. Relative to body mass, therefore, the extremities of C. albifrons scale much faster than those of C. apella. This implies that at any given postnatal body mass, C. alblfrons is longer limbed that C. apella. Conversely, C. apella is heavier than C. albifrons at any given limb length or age. We suggest that such differences in body mass distribution are causally related to differences in locomotor behavior and foraging strategies. Specifically, the relatively long-limbed C. albifrons is probably more cursorial and tends to travel longer distances each day than C. apella. C. apella is a much more deliberate quadruped and is also characterized by especially vigorous and powerful foraging and feeding behaviors. We also compare our results to other (mostly cross-sectional) studies of skeletal growth allometry in nonhuman primates.
白额卷尾猴和褐卷尾猴是来自南美洲部分同域分布的卷尾猴，已知它们在成年体重和身体比例上有很大差异。与白额卷尾猴更为纤细、四肢相对较长的身体设计相比，褐卷尾猴拥有强壮、矮胖的体型。然而，这两种同属物种的平均出生体重和成年体长非常相似，无法用于区分它们。本研究考察了四肢（肱骨、桡骨、手、股骨、胫骨、足）的纵向生长速率和个体发育缩放模式，以记录与年龄和体重增加相关的骨骼变化的性质和程度。我们的数据表明，这两个物种四肢的六个骨骼组成部分的生长速率仅略有不同，且在某种程度上不一致。然而，褐卷尾猴的体重增长速度始终更快。因此，相对于体重而言，白额卷尾猴四肢的缩放速度比褐卷尾猴快得多。这意味着在任何给定的出生后体重下，白额卷尾猴的四肢比褐卷尾猴更长。相反，在任何给定的肢体长度或年龄下，褐卷尾猴都比白额卷尾猴更重。我们认为，这种体重分布的差异与运动行为和觅食策略的差异存在因果关系。具体而言，四肢相对较长的白额卷尾猴可能更善于奔跑，并且每天的移动距离可能比褐卷尾猴更长。褐卷尾猴是一种更为从容的四足动物，其特点还包括特别有力且强劲的觅食和进食行为。我们还将我们的结果与其他（大多为横断面）关于非人类灵长类动物骨骼生长异速生长的研究进行了比较。
