Scapular Morphology and Forelimb Use during Foraging in Four Sympatric Cercopithecids

Abstract

Most investigations of primate scapular morphology use differences in locomotion to explain variation; less is known about how scapular geometry covaries with nonlocomotor behavior. We examined forelimb use during foraging in 4 cercopithecids ranging throughout the Ivory Coast's Tai Forest. During 5-min feeding bouts, we recorded the frequency individuals of Piliocolobus badius, Colobus polykomos, Cercocebus atys and Cercopithecus diana performed 5 forelimb behaviors involved in the acquisition and introduction of food to the oral cavity. Scapulae from these populations were examined to determine whether differences in forelimb use were reflected in features known to correspond with varying degrees of arm flexion, abduction and elevation. Our results reveal that the species differ markedly in forelimb use and that these differences are interpretable via their scapular morphology. For example, P. badius engages in more frequent flexion, abduction and elevation of the arm above the head relative to C. polykomos, and red colobus scapulae are longer craniocaudally and have larger, more cranially directed supraspinous fossae than those of closely related black-and-white colobus. Our attempt to explore how nonlocomotor behavior covaries with skeletal morphology should provide for more informed interpretations of the primate fossil record.

Anatomical and radiographic study of the scapula in juveniles and adults of Tamandua mexicana (Xenarthra: Myrmecophagidae)

“…For human and domestic mammals, there is no specific term for this surface (Federative International Committee on Anatomical Terminology, ; ICVGAN, ), but it can be seen a surface for the origin of the m. teres major in the graphic representations of the scapula in the domestic dog (Evans & de Lahunta, ) and the human (Standring, ). Even in non‐human primates, this surface has already been previously described (Mivart, ), and current studies have indicated its presence such as in Lemur catta (Makungu, Groenewald, Plessis, Barrows, & Koeppel, ), cercopithecids (Dunham, Kane, & McGraw, ) and Saguinus leucopus (Vélez‐García, Monroy‐Cendales, & Castañeda‐Herrera, ). However, these are different to Tamandua, because this surface is not so great as to give origin to the m. subscapular, similar to what occurs in armadillos, where it is observed that this surface is wide but only at the level of the caudal angle (Acuña, Sidorkewicj, Popp, & Casanave, ; Miles, ; Olson, Womble, Thomas, Glenn, & Butcher, ; Taylor, ), which is considered by Monteiro and Abe () as an expansion of the infraspinous fossa in armadillos and developed due to the greater retraction required by the thoracic limb in order to dig—where a major part of the force is contributed by the m. teres major for their fossorial habits (Olson et al, ).…”

“…This surface has also been mistakenly considered part of the infraspinous fossa in M. tridactyla (Lima et al, 2013) , 1998;ICVGAN, 2017), but it can be seen a surface for the origin of the m. teres major in the graphic representations of the scapula in the domestic dog (Evans & de Lahunta, 2013) and the human (Standring, 2016). Even in non-human primates, this surface has already been previously described (Mivart, 1866), and current studies have indicated its presence such as in Lemur catta (Makungu, Groenewald, Plessis, Barrows, & Koeppel, 2015), cercopithecids (Dunham, Kane, & McGraw, 2015) and Saguinus leucopus (Vélez-García, Monroy-Cendales, & Castañeda-Herrera, 2019).…”

Gross anatomy of the shoulder and arm intrinsic muscles in the white‐footed tamarin (Saguinus leucopus – Günther, 1876): Inter‐ and intraspecific anatomical variations

“…34,36 The origin of the teres major muscle from a specific bony feature of the scapula located on the caudal angle has been previously reported in S leucopus 4 and other primates. 40,41 The origin and insertion of the subscapularis muscle in S leucopus was similar to most other primates, 11,[22][23][24][27][28][29][30][31][32]37 humans, 10,14,26 and domestic mammals. 33,34,36 In Symphalangus syndactylus, the origin of this muscle can reach the caudal margin of the scapula as a variant, 31 which was constant in S leucopus.…”

Semicircular Canal Size and Locomotion in Colobine Monkeys: A Cautionary Tale

“…Hard and soft tissue characteristics generally associated with habitual locomotor modes are found in the limbs [Fleagle, 1976[Fleagle, , 1977, although non-locomotor activity also affects the postcrania [Dunham et al, 2015]. More recently, however, the advent of modern imaging techniques has allowed the examination of the internal portions of the cranium, including the labyrinth of the temporal bone, which includes the organ of balance [Spoor and Zonneveld, 1998].…”