Strange deer with 'gills' on muzzle....

When in high school- grad. 1978- my science class had to locate the most odd animals found on the planet and do a report on them. I am not making this up, one kid found some newly discovered and quite rare (indeed!) deer in upper Mongolia or (somewhere there abouts)that had actual working 'gills' as most aquatic life does located in their snouts. Of course that was years ago and I am unable to locate the name, habitat or actual rarity of these animals, do you have know of a way to locate any information on these creatures? My son is wanting to do a report on them and we need information if at all possible. Thank you... quido