The morphological variation of the scapula of bats, in a phylogenetic context, is still unknown. However, several descriptive–comparative and morphofunctional studies about the scapular girdles and forelimbs and their importance in the wing‐beat cycle are well known and documented. In this study, we tested the hypothesis that there is a conjunction of factors that influences the size and shape of the scapula in bats, such as phylogenetic effects and lifestyle traits. We analyzed the variation in size and shape of the scapula of six families of bats (277 specimens from 91 species) using geometric morphometrics in a phylogenetic context. The results indicate that phylogenetic signal for both size and shape of the scapula is strong. The phylomorphospace indicates a clear separation by families, with Phyllostomidae and Molossidae being the most different from each other. Phylogenetic signal was also strong for size and shape of the scapula within the family Phyllostomidae. According to phylogenetic analyses of variance, the shape and size of the scapula are not affected by the lifestyle of the bats, independently of phylogeny, except for the type of flight in Vespertilionidae. The results in this family indicate that, in addition to strong phylogenetic signal in scapular morphology, there is evidence of some evolutionary convergence that supports an adaptive interpretation. However, the assessments to test morphological convergence failed to find phenotypic similarity within states of lifestyle traits, except for insectivore species which presented some degree of morphological resemblance in the shape of the scapula. Thus, it seems that at higher taxonomic levels (e.g., among families) the morphology of the scapula is phylogenetically conserved, whereas patterns of convergent evolution are visible at lower taxonomic levels (e.g., within families).
Here we present detailed descriptions and comparisons of the axial skeleton of seven species of bats belonging to five subfamilies of Phyllostomidae of different trophic guilds. The material examined consisted of 34 complete skeletons of seven species. For five of the studied species, previous descriptions have not been conducted, and for the vampires only limited information is available, so that descriptions for these species are here completed. The axial skeleton has characters that allow grouping of the species phylogenetically of the same subfamily and by feeding habits. At the same time, there are characters that associate species from different subfamilies with different types of diet or ways to obtain food.
a b s t r a c tA conspicuous synapomorphy of the marsupial genus Didelphis is the hypertrophied spinous process of cervical vertebrae (C). The tall, thick spinous processes of C2 to C6 interlock preventing any movement of the neck. A functional interpretation of this structure has been elusive. On the basis of osteological specimens of D. albiventris and D. virginiana, we propose a possible function. These specimens show large, partially healed wounds in the spinous processes, indicating that the specimens survived major traumatisms probably caused by carnivorans, so that the spinous processes may have acted as neck armor. Didelphis exhibits several other, well-known defensive traits which, in combination with generalized feeding and locomotor habits, altogether may have helped the lineage survive the Late Tertiary extinction waves in South
A new material of a Quaternary waterfowl is described here. The implications of this finding, in the context of the dispersal of Anatidae in the past, are discussed. The specimen consists in a partial humerus coming from the Upper Pleistocene of austral Chaco from Santiago del Estero Province, Argentina. The specimen here described belongs to the tribe Cygnini, being larger than most members of the clade. The humerus shows different size than with other members of the tribe Cygnini, being larger than the humeri referred to the Andean goose (Oressochen melanopterus), the Sheldgeese of the genus Chloephaga, the Comb Duck (Sarkidiornis sylvicola), and larger than the Ruddy Shelduck (Tadorna ferruginea). However, the humerus have several anatomical characters indicating that it belongs to a basal anserine duck. These combinations of features allow us to assign this fossil to a species of waterfowl: Coscoroba coscoroba. This finding, it context with the history of the South American Cygnini, provides new environmental interpretations associated with wetlands, which will be tested in the austral Chaco and Northern Pampa through future multi-proxy studies. Keywords: Anseriformes bird, goose, Coscoroba coscoroba, Quaternary, South America, Santiago del Estero.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.