 But few skeletal characteristics are known to reliably indicate relationships among the vesper bats, so all that can be said at present is that it lacks obvious traits suggesting it belongs to one of the minor vesper bat subfamilies.It was a relatively small species of bat, with linear measurements about 25% smaller than the Hawaiian hoary bat which weighs 10-15 grams and has a wingspan of around a dozen cm.Notably, the skull's muzzle is somewhat more narrow than in its fellow species, and the nasal region is markedly concave (instead of barely convex in "A. semotus"), resulting in the skull having a pronounced snout.