Variation of craniodental traits in russet rats Euryoryzomys russatus (Wagner, 1848) (Rodentia: Cricetidae: Sigmodontinae) from eastern Atlantic forest

GUSTAVO SIMÕES LIBARDI; ALEXANDRE REIS PERCEQUILLO

ZOOLOGISCHER ANZEIGER

ELSEVIER GMBH

Año: 2016 vol. 262 p. 57 - 74

0044-5231

The analyses of geographic variation and the detection of discontinuities among populations of a giventaxa is a fundamental step on evolutionary studies. Some recent studies have demonstrated that alongthe Atlantic Forest of eastern Brazil there are some phylogenetic and phylogeographic discontinuitiesrecovered with molecular markers for several groups of organisms, granting the proposition of biogeographichypothesis for species diversification in this biome. For instance, a phylogeographic studyusing cytochrome b sequences demonstrated geographic pattern of genetic variation in the oryzomyinerodent Euryoryzomys russatus. Considering the widespread occurrence of E. russatus, its susceptibility tofragmentation, and the existence of geographic structure in the genetic variation mentioned above, E.russatus stands as an interesting species to describe the geographic pattern of craniodental variation.Therefore, we aim to evaluate the morphometric variation patterns coupled with the actual knowledgeregarding the evolution of the Atlantic Forest biota, in order to test the hypothesis that the phenotypeof E. russatus exhibits a structured pattern of variation along the Atlantic Forest similar to that describedfor the cytochrome b gene on continental and coastal islands samples. Our results showed that there iscongruence between the gaps here described on morphometric data and the genetic data described inliterature. We also detected important variation in size between some insular populations and the continent.Geographic patterns of morphometric variation observed for E. russatus were compared to otherpatterns of diversity for the Atlantic biome, and discussed under historical biogeographic context. Weconcluded that study of morphometric variation might offer important support to phylogeographic andbiogeographic hypothesis based on molecular markers and provide a better scenario on the expressionof the phenotypic variation.