Through a glass darkly: taxonomy, phylogeny, and biostratigraphy of the Olenellina

Abstract

The Olenellina is an exclusively Early Cambrian trilobite suborder that dominates the later Early Cambrian trilobite faunas of Laurentia and constitutes a lesser component of the trilobite faunas of Siberia, Baltica, Avalonia and the western sector of Gondwana/peri-Gondwana (Morocco, Spain, and eastern Germany). Two superfamilies, seven families, 10 subfamilies, 45 genera, and five subgenera are distinguished primarily on characters of the cephalon. Major revisions from previous usage primarily involve the Laurentian Olenellidae. New taxa are described. Intercontinental correlation of Lower Cambrian strata is hampered by high endemism of genera and species, especially among the Olenellina. Biostratigraphic and biogeographic analysis of the Olenellina suggests increasing geographic isolation of Laurentia during Early Cambrian time and that Laurentian Olenellidae are mostly younger than the Olenellina of the other Cambrian continents. -from Authors