▁morph ology , ▁behav iors , ▁and ▁evolution . ▁ ▁In ▁the ▁late ▁ 1 9 5 0 s , ▁nearby ▁nuclear ▁weapons ▁testing ▁by ▁the ▁United ▁States ▁military ▁accident ally ▁caused ▁all ▁of ▁the ▁islands ▁of ▁Hy - yi - yi ▁to ▁sink ▁into ▁the ▁ocean , ▁destroy ing ▁all ▁traces ▁of ▁the ▁r hin og r ades ▁and ▁their ▁unique ▁e cos ystem . ▁Also ▁killed ▁were ▁all ▁the ▁world ' s ▁Rh in og rad ent ia ▁research ers , ▁who ▁were ▁att ending ▁a ▁conference ▁on ▁Hy - yi - yi ▁at ▁the ▁time . ▁The ▁book ' s ▁ep ilog ue , ▁cred ited ▁to ▁Ste iner ▁in ▁his ▁capacity ▁as ▁the ▁book ' s ▁illustr ator , ▁explains ▁that ▁St ü mp ke ▁had ▁sent ▁the ▁book ' s ▁materials ▁to ▁Ste iner ▁to ▁serve ▁as ▁the ▁basis ▁for ▁illustr ations ▁in ▁prepar ation ▁for ▁publication . ▁Following ▁the ▁dis aster , ▁it ▁is ▁the ▁only ▁remaining ▁record ▁of ▁the ▁subjects ▁it ▁describes . ▁ ▁Bi ological ▁characteristics ▁and ▁behavior ▁ ▁Rh in og r ades ▁are ▁m amm als ▁character ized ▁by ▁a ▁nose - like ▁feature ▁called ▁a ▁" nas or ium ", ▁the ▁form ▁and ▁function ▁of ▁which ▁vary ▁significantly ▁between ▁species . ▁According ▁to ▁St ü mp ke , ▁the ▁order ' s ▁remarkable ▁variety ▁was ▁the ▁natural ▁outcome ▁of ▁evolution ▁acting ▁over ▁millions ▁of ▁years ▁in ▁the ▁remote ▁Hy - yi - yi ▁islands . ▁All ▁the ▁ 1 4 ▁families ▁and