Fifteen element septimembrate apparatus structure of the early Ordovician conodont Oepikodus evae LINDSTRÖM from Australia and Sweden

A 15 element septimembrate apparatus structure for the Early Ordovician (Bendigonian to Chewtonian-Arenig) conodont Oepikodus evae (LINDSTRÖM) is established using bedding plane assemblages from Victoria, Australia. Detailed element morphology is confirmed using well preserved discrete elements from Sweden. The complete apparatus consists of a pair of M elements, a single quadriform Sa element, two pairs of Sc elements, and a pair each of Sb, Sd, Pb, and Pa elements. The skeletal architecture of the Oepikodus apparatus appears to be slightly different from that of ozarkodinid conodonts. The functional morphology of the P elements of Oepikodus evae is that of a hyalion apparatus in which the cusps are pointed in the same direction and the inner lateral surfaces of the paired elements are in contact.