Resumo

TETA, Pablo  e  PARDINAS, Ulyses F. J.. Qualitative and quantitative morphological variation in Abrothrix longipilis (Cricetidae, Sigmodontinae). Mastozool. neotrop. [online]. 2014, vol.21, n.2, pp.291-309. ISSN 0327-9383.

We studied the alpha taxonomy of Abrothrix longipilis (Waterhouse, 1837), one of the most widely distributed and abundant Abrotrichini along the southern portion of Argentina and Chile. We conducted a qualitative (6 discrete characters) and quantitative (18 skull and dental measurements) morphological analysis of 477 adult specimens, grouped first by geographical criteria and later by membership to the clades defined in a previous phylogeographical study based on 2 molecular markers. Multivariate analyses (principal component analysis, discriminant analyses) suggested that in its current conception A. longipilis is a species-complex that includes at least two nominal taxa, A. longipilis stricto sensu, here restricted to Central Chile, and A. hirta (Thomas, 1895), distributed in southern Chile and southwestern Argentina. Populations of A. hirta showed a moderate correspondence between phylogeographic and phenotypic patterns. Tentatively, we considered that general size in A. hirta is mostly linked to environmental conditions (with larger individuals in forested areas, under high primary productivity conditions and the smaller ones in arid environments of low productivity) rather than to their inclusion in different clades. Under this scenario, morphological differentiation was probably driven by differential selection across a sharp ecological gradient, in spite of gene flow (divergence-with-gene-flow model).

Palavras-chave : Abrotrichini; Argentina; Chile; Morphometrics; Muroidea; Rodentia; Skull; Taxonomy.

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