Geographic variation in quantitative skull traits and systematic of southern populations of the leaf-eared mice of the Phyllotis xanthopygus complex (Cricetidae, Phyllotini) in southern South America.

TETA P; PABLO JAYAT; C. LANZONE; A. OJEDA; A. NOVILLO; OJEDA R.A.

ZOOTAXA

MAGNOLIA PRESS

Lugar: Auckland; Año: 2018

1175-5326

Abstract.-The leaf-eared mice of the genus Phyllotis(Cricetidae, Phyllotini) encompasses at least 20 species of medium-sizedNeotropical rodents mostly distributed throughout the Andean region. The limitsand contents of Phyllotis werereviewed by several authors, based both on morphological and molecular sets ofevidences. However, no integrative approaches were conducted based on largesamples of individuals with a wide geographical coverage. The purposes of thispaper are: i) to evaluate species limits;ii) to test the congruencebetween molecular and quantitative morphological evidences, and iii) to examinethe rates of phenotypic evolution in quantitative skull morphology of Phyllotis in southern South America. Ourresults support the specific status of P.bonariensis, a geographically isolated form that was either considered as avalid species or as a synonym of P. xanthopygus. Morphological and moleculardata linked P. bonariensis withpopulations from central Argentina traditionally referred as P. xanthopygus vaccarum. Individualsbelonging to populations from central and southern Patagonia (P. x. xanthopygus) were remarkablyhomogeneous in their skull morphology, showing a subtle differentiation fromthose of north-central and west-central Argentina referred to P. x. vaccarum. We found some incongruence between groups inferred frommorphological (this work) and molecular results of previous studies. This isthe case of the north-central and west-central populations, where morphologicaltraits do not show the strong differentiation detected by molecular characters.Rates of phenotypic change indicate a low correlation between time ofdivergence and phenotypic distance. Our results highlightthe need forintegrativetaxonomic studies, not only to delimitate taxonomic unitsbut also for a better and more comprehensive understanding of populationdifferentiation, variability, and phenotypic divergence rates.