MARJUMAN (CAMBRIAN) AGNOSTOID TRILOBITES OF THE COW-HEAD GROUP, WESTERN NEWFOUNDLAND

Shelf-derived limestone boulders in debris flows of the Cow Head Group , western Newfoundland, have yielded rich mid- to Upper Cambrian trilo bite faunas. The agnostoid component of Majuman boulders consists of 2 3 species assigned to 11 genera; Kormagnostus boltoni and Kormagnostus ? copelandi are new. Cladistic parsimony analysis of the Ptychagnostid ae Kobayashi reduces this family to 3 genera: Ptychagnostus Jaekel, Ps eudophalacroma Pokrovskaya and Lejopyge Hawle and Corda; Ptychagnostus includes three non-obligate subgenera: P. (Ptychagnostus) (= Tomagnos tus Howell); P. (Goniagnostus) Howell and P. (Aotagnastus) Opik (= Myr mecomimus Opik) Correlation with zonations established in northern Can ada and Utah indicates that the Cow Head Group includes a nearly compl ete sequence of agnostoid faunas from the mid-Cambrian Ptychagnostus g ibbus Zone to the Upper Majuman Cedaria brevifrons Zone.