▁a ▁dozen ▁cm . ▁Not ably , ▁the ▁sk ull ' s ▁m uzz le ▁is ▁somewhat ▁more ▁narrow ▁than ▁in ▁its ▁fellow ▁species , ▁and ▁the ▁nas al ▁region ▁is ▁marked ly ▁con ca ve ▁( inst ead ▁of ▁bare ly ▁convex ▁in ▁A . ▁sem ot us ), ▁resulting ▁in ▁the ▁sk ull ▁having ▁a ▁pron ounced ▁sn out . ▁How ▁its ▁nose ▁looked ▁in ▁life ▁is ▁unknown ; ▁the ▁V esper til ion idae ▁generally ▁produce ▁e ch ol ocation ▁sounds ▁with ▁the ▁voice box ▁and ▁not ▁with ▁the ▁nose , ▁and ▁consequ ently ▁lack ▁the ▁elaborate ▁ul tras ound - f oc using ▁nose ▁append ages ▁of ▁b ats ▁that ▁use ▁the ▁latter ▁technique . ▁To ▁what ▁extent ▁this ▁applied ▁to ▁Syn empor ion ▁is ▁not ▁clear ; ▁most ▁of ▁the ▁tribes ▁it ▁may ▁belong ▁to ▁contain ▁a ▁few ▁species ▁with ▁nose ▁or ▁upper ▁j aw ▁append ages . ▁These ▁are ▁rarely ▁as ▁elaborate ▁as ▁those ▁of ▁horses ho e ▁b ats ▁( R hin ol oph idae ), ▁for ▁example , ▁and ▁are ▁sometimes ▁related ▁to ▁sexual ▁selection ▁rather ▁than ▁e ch ol ocation ; ▁there ▁is ▁no ▁indic ation ▁that ▁Syn empor ion ▁had ▁marked ▁sexual ▁differences , ▁and ▁altogether ▁its ▁sk ull ▁shape ▁is ▁not ▁too ▁different ▁from ▁that ▁of ▁e . g . ▁Austral as ian ▁big - eared ▁b ats ▁( N y ct oph ilus ). ▁ ▁One ▁notable ▁difference ▁from ▁all ▁v esper ▁b ats ▁it ▁was ▁compared ▁with , ▁however ,