like ▁structures ▁round ▁the ▁foot . ▁Instead ▁he ▁argued ▁that ▁they ▁were ▁evidence ▁of ▁extern ally ▁visible ▁segment ation , ▁which ▁is ▁found ▁in ▁pol ych a etes ▁but ▁not ▁in ▁m oll us cs . ▁He ▁concluded ▁that ▁W iw ax ia ▁was ▁an ▁evolution ary ▁" a unt " ▁of ▁pol ych a etes , ▁while ▁Od ont og ri ph us ▁could ▁be ▁an ▁evolution ary ▁" a unt " ▁of ▁pol ych a etes ▁or ▁of ▁m oll us cs ▁or ▁of ▁bra chi op ods ▁– ▁or ▁even ▁a ▁" gre at ▁a unt " ▁of ▁all ▁three , ▁as ▁it ▁could ▁have ▁been ▁an ▁early ▁member ▁of ▁the ▁l oph ot ro cho zo a , ▁a ▁" super - ph yl um " ▁that ▁includes ▁the ▁pol ych a etes , ▁m oll us cs ▁and ▁bra chi op ods . ▁ ▁In ▁January ▁ 2 0 0 7 ▁Car on , ▁Sch el tem a , ▁et ▁al . ▁published ▁a ▁vig orous ▁reply ▁to ▁But ter field ' s ▁arguments ▁– ▁near ▁the ▁end ▁they ▁wrote , ▁" Many ▁of ▁But ter field ’ s ▁mis con ception s ▁might ▁well ▁have ▁been ▁avoided ▁had ▁he ▁taken ▁the ▁opportunity ▁to ▁examine ▁all ▁the ▁new ▁material ▁that ▁formed ▁the ▁basis ▁of ▁our ▁study . ▁… " ▁They ▁said ▁they ▁had ▁found ▁in ▁body ▁foss ils ▁of ▁Od ont og ri ph us ▁visible ▁traces ▁of ▁the ▁memb rane ▁on ▁which ▁its ▁to oth - rows