 In 2010 , Pablo <unk> and colleagues reviewed the members of the Akodon boliviensis species group , including A. spegazzinii , in Argentina . They could not find clear differentiation in either morphological or molecular characters between animals belonging to A. alterus , A. leucolimnaeus , A. spegazzinii , and A. tucumanensis , and consequently concluded that they all represent a single species . Although genetic variation is relatively high within A. spegazzinii , there is no clear geographic structure among haplotypes from different regions . The next year , Ulyses Pardiñas and colleagues concluded that A. oenos , which had formerly , and incorrectly , been placed in the A. varius species group , was in fact another synonym of A. spegazzinii . The proliferation of scientific names for this one species occurred because of the terseness of the original description of A. spegazzinii , and a lack of large samples and of appreciation of the substantial variation occurring within A. spegazzinii . 
