Postcranial Skeleton of Glironia venusta (Didelphimorphia, Didelphidae, Caluromyinae): Description and Functional Morphology

FLORES, D; DIAZ, M.

Zoosystematics & Evolution

Wiley

Lugar: Berlin; Año: 2009 vol. 85 p. 311 - 339

1435-1935

The postcranial skeleton of the neotropical living marsupial Glironia venusta is describedand compared in a functional framework. Osteological and myological charactersof 19 species of living didelphids and some additional placentals were consulted asmodels to explain functional implications from the morphology. The skeleton of G. venustaprovides evidence about locomotory behavior and specific capacities of movements,and reveals patterns comparable to arboreal didelphids and placentals with highcapacity to climb. In general terms, G. venusta has few diagnostic characters in thecontext of the didelphid sample analyzed, which includes 19 species representing allrecognized clades in the family (second sacral not fused to the ilium, humeral greatertrochanter well developed, tibia shorter than femur). Most of the postcranial pattern inG. venusta is consistent with arboreal locomotion, but unlike Caluromys and Caluromysiops,it seems to have faster locomotion. The morphology of the vertebral column, atthe thoracic and lumbar portions, shows features that allow powerful lateral and sagittalmovements during different phases of locomotion. The patterns evidenced in the forelimbs,pelvic girdle, and hindlimbs point to arboreal habits as well, except for somefeatures on the humerus, illium and fibula. Even if most didelphids have been catalogedas generalized with respect to their mode of gait, the skeletal morphology ofG. venusta and the high variation existent in further neotropical marsupials with a varietyof body sizes, reveal a diverse combination of features associated to specializedcapacities of movements. This indicates a diversity of locomotory modes and posturesin didelphids.