This video says about itself:
Green Ambassador Brazil Bat Research
11 May 2007
The video is in Portuguese, but its subtitles can be switched to English or other languages.
From Wildlife Extra:
New bat species discovered
The scientists Drs. Ricardo Moratelli and Daniela Dias examined both wild and museum specemins of L. mordax, when they realised, rather than looking at one species they were looking at two different species.
Called L. inexpectata, the new species has considerably paler ventral (abdominal) fur and some of their measurements were inconsistent with L. mordax, including differences in the skull and the teeth morphology.
The scientific description of the new species is here.