Beyond the carapace: skull shape variation and morphological systematics of long-nosed armadillos (genusDasypus) Journal Articles uri icon

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abstract

  • BackgroundThe systematics of long-nosed armadillos (genusDasypus) has been mainly based on a handful of external morphological characters and classical measurements. Here, we studied the pattern of morphological variation in the skull of long-nosed armadillos species, with a focus on the systematics of the widely distributed nine-banded armadillo (Dasypus novemcinctus).MethodsWe present the first exhaustive 3D comparison of the skull morphology within the genusDasypus, based on micro-computed tomography. We used geometric morphometric approaches to explore the patterns of the intra- and interspecific morphological variation of the skull with regard to several factors such as taxonomy, geography, allometry, and sexual dimorphism.ResultsWe show that the shape and size of the skull vary greatly amongDasypusspecies, withDasypus pilosusrepresenting a clear outlier compared to other long-nosed armadillos. The study of the cranial intraspecific variation inDasypus novemcinctusevidences clear links to the geographic distribution and argues in favor of a revision of past taxonomic delimitations. Our detailed morphometric comparisons detected previously overlooked morphotypes of nine-banded armadillos, especially a very distinctive unit restricted to the Guiana Shield.DiscussionAs our results are congruent with recent molecular data and analyses of the structure of paranasal sinuses, we propose thatDasypus novemcinctusshould be regarded either as a polytypic species (with three to four subspecies) or as a complex of several distinct species.

authors

  • Poinar, Hendrik
  • Hautier, Lionel
  • Billet, Guillaume
  • de Thoisy, Benoit
  • Delsuc, Frédéric

publication date

  • 2017

published in