▁in ▁which ▁the ▁only ▁known ▁spec im ens ▁of ▁Od ont og ri ph us ▁and ▁W iw ax ia ▁were ▁found . ▁Some ▁group ings ▁of ▁these ▁micro - f oss ils ▁showed ▁a ▁consistent ▁arrangement ▁that ▁he ▁interpreted ▁as ▁an ▁" art ic ulated ▁appar atus " ▁with ▁tens ▁of ▁closely ▁spac ed ▁to oth ▁rows , ▁apparently ▁mounted ▁on ▁an ▁organ ic ▁base , ▁and ▁with ▁notice able ▁signs ▁of ▁wear ▁in ▁the ▁rows ▁at ▁one ▁end . ▁The ▁rows ▁were ▁not ▁quite ▁identical , ▁but ▁he ▁noted ▁that ▁some ▁modern ▁ap lac op hor an ▁m oll us cs ▁show ▁similar ▁variations . ▁He ▁concluded ▁that ▁the ▁" art ic ulated ▁appar atus " ▁was ▁a ▁genu ine ▁m oll us can ▁rad ula , ▁most ▁similar ▁to ▁those ▁of ▁modern ▁ap lac op hor ans ▁or ▁g ast rop ods . ▁He ▁then ▁commented ▁on ▁the ▁contrast ▁between ▁this ▁appar atus ▁and ▁the ▁two ▁or ▁rarely ▁three ▁widely ▁spac ed ▁and ▁more ▁heter eg ene ous ▁to oth - rows ▁found ▁in ▁foss ils ▁of ▁Od ont og ri ph us ▁and ▁W iw ax ia , ▁and ▁concluded ▁that ▁Od ont og ri ph us ▁and ▁W iw ax ia ▁were ▁unlikely ▁to ▁be ▁m oll us cs . ▁ ▁However , ▁a ▁ 2 0 1 2 ▁study ▁re - ex am ined ▁the ▁mouth parts ▁of ▁these ▁two ▁gener a , ▁and ▁identified ▁problems ▁with ▁previous ▁interpret ations . ▁Most ▁important ly , ▁the ▁mouth