Upper Cambrian (Marjuman–Steptoean) trilobites from the Port Au Port Group, western Newfoundland

Abstract

The Port au Port Group of western Newfoundland is a sequence of Upper Cambrian (Marjuman–Sunwaptan) shallow subtidal–supratidal carbonates and fine siliciclastics that are organized into three large scale sedimentary grand cycles. Low diversity trilobite faunas from the Marjuman and Steptoean portions (March Point and Petit Jardin Formations) include 17 species that are assigned to 16 genera; one species, Coosina kindlei, is new. Biostratigraphic analysis confirms earlier suggestions that the grand cycles boundaries record major intervals of onlap that can be recognized in other parts of North America and may be related to eustatic sea level rises.