us , ▁with ▁a ▁prominent ▁cr est ▁on ▁the ▁kne e . ▁The ▁ast rag alus ▁and ▁calc ane um ▁( ank le ▁b ones ) ▁were ▁f used ▁together , ▁and ▁the ▁feet ▁bore ▁three ▁functional ▁digits , ▁with ▁a ▁smaller ▁first ▁digit ▁that ▁did ▁not ▁contact ▁the ▁ground . ▁ ▁Disc overy ▁and ▁naming ▁▁▁ ▁French ▁pale ont ologist ▁Charles ▁Dep é ret ▁described ▁the ▁first ▁ther op od ▁remains ▁from ▁north western ▁Mad agas car ▁in ▁ 1 8 9 6 . ▁These ▁included ▁two ▁teeth , ▁a ▁cla w , ▁and ▁some ▁verte bra e ▁discovered ▁along ▁the ▁B ets ib oka ▁River ▁by ▁a ▁French ▁army ▁officer ▁and ▁depos ited ▁in ▁the ▁collection ▁of ▁what ▁is ▁now ▁the ▁Univers ité ▁Claude ▁Bernard ▁Lyon ▁ 1 . ▁Dep é ret ▁referred ▁these ▁foss ils ▁to ▁the ▁genus ▁Meg al osa urus , ▁which ▁at ▁the ▁time ▁was ▁a ▁waste b asket ▁tax on ▁containing ▁any ▁number ▁of ▁un related ▁large ▁ther op ods , ▁as ▁the ▁new ▁species ▁M . ▁c ren at iss im us . ▁This ▁name ▁is ▁derived ▁from ▁the ▁Latin ▁word ▁c ren atus ▁(" not ched ") ▁and ▁the ▁suffix ▁- iss im us ▁(" most "), ▁in ▁reference ▁to ▁the ▁numerous ▁ser r ations ▁on ▁both ▁front ▁and ▁rear ▁edges ▁of ▁the ▁teeth . ▁Dep é ret ▁later ▁re ass igned ▁the ▁species ▁to ▁the ▁North ▁American ▁genus ▁D rypt osa urus , ▁another ▁poor ly ▁known ▁tax on . ▁ ▁N umer