▁and ▁the ▁ratio ▁of ▁the ▁proxim od ist al ▁length ▁to ▁trans verse ▁bread th ▁of ▁the ▁ast rag alus ▁ 0 . 5 5 ▁or ▁greater . ▁Sau rop od ▁expert ▁Michael ▁Daniel ▁D ' Em ic ▁pointed ▁out ▁that ▁the ▁criteria ▁chosen ▁were ▁to ▁an ▁extent ▁arbitrary ▁and ▁that ▁they ▁would ▁require ▁abandon ing ▁the ▁name ▁Br ont osa urus ▁again ▁if ▁newer ▁anal ys es ▁obtained ▁different ▁results . ▁M amm al ▁p ala e ont ologist ▁Donald ▁Pro ther o ▁critic ized ▁the ▁mass ▁media ▁reaction ▁to ▁this ▁study ▁as ▁super f icial ▁and ▁prem ature , ▁con cluding ▁that ▁he ▁would ▁keep ▁" Br ont osa urus " ▁in ▁quotes ▁and ▁not ▁treat ▁the ▁name ▁as ▁a ▁valid ▁genus . ▁ ▁Valid ▁species ▁ ▁Many ▁species ▁of ▁A pat osa urus ▁have ▁been ▁designated ▁from ▁sc ant ▁material . ▁Marsh ▁named ▁as ▁many ▁species ▁as ▁he ▁could , ▁which ▁resulted ▁in ▁many ▁being ▁based ▁upon ▁fragment ary ▁and ▁ind ist ingu ish able ▁remains . ▁In ▁ 2 0 0 5 ▁Paul ▁Up ch urch ▁and ▁colle agues ▁published ▁a ▁study ▁that ▁analyz ed ▁the ▁species ▁and ▁spec imen ▁relationships ▁of ▁A pat osa urus . ▁They ▁found ▁that ▁A . lou is ae ▁was ▁the ▁most ▁bas al ▁species , ▁followed ▁by ▁FM N HP 2 5 1 1 2 , ▁and ▁then ▁a ▁pol yt omy ▁of ▁A . ajax , ▁A . par v us , ▁and ▁A . ex c els us . ▁Their