MUSCULAR ANATOMY OF THE FORELIMBS OF THE LESSER GRISON (GALICTIS CUJA), AND A FUNCTIONAL AND PHYLOGENETIC OVERVIEW OF MUSTELIDAE AND OTHER CANIFORMIA

ERCOLI, MARCOS D.; ÁLVAREZ, ALICIA; STEFANINI, MANUEL I.; BUSKER, FELIPE; MORALES, MIRIAM M.

JOURNAL OF MAMMALIAN EVOLUTION

SPRINGER

Lugar: Berlin; Año: 2014 vol. 22 p. 57 - 91

1064-7554

The extrinsic and intrinsic forelimb musculature ofthe lesser grison (Galictis cuja), a short-legged mustelid ofsouthern South America, is studied for the first time. Wepresent descriptions, muscular maps, and weight data. Muscularanatomy description of the lesser grison provides theframework for discussing the myological diversity ofmustelids and other caniforms, for addressing nomenclaturalproblems (such as synonymy and homonymy), and forhighlighting some functional and phylogenetically informativetraits.We recognize in the lesser grison features shared byall mustelid species, and some other caniforms, especiallymephitids, such as the presence of rhomboideus profundus,an angular head of triceps brachii, and, apparently, the absenceof a flexor digitorum brevis manus. An unexpected record ofarticularis humeri, a proximal origin of the brachioradialis,and the absence of the tensor fascia antebrachii are recordedfor this species. As other ictonychines and mustelines, Galictiscuja possesses stronger and subdivided protractors and sagittalrotators of the forelimbs, as well as shoulder and elbowextensors. These features allow for resistance in landing duringbounds and increase the stride length during epigean andsubterranean crouched locomotion. Powerful neck musculatureassists during hunting and carrying of prey. Weakness ofsome retractors and intrinsic flexors is related to a relativelyminor importance of the forelimbs as propellers duringbounding and the lack of other specializations. The configurationof the rhomboideus and the absence of coracobrachialisseem to be informative at the subfamiliar level withinMustelidae. The comprehensive and comparative review ofavailable information leads us to propose possible solutions toold nomenclatural problems and of identification. This allowsus to reassess of some myological features as diagnostic ofcaniform clades.