New Early Devonian pteraspidids (Agnatha, Heterostraci) from Death Valley National Monument, southeastern California

Abstract

Two species and genera of pteraspidids (Agnatha, Heterostraci), Blieckaspis priscillae n. gen., and Panamintaspis snowi n. gen. and n. sp., together with two undetermined species, are described from the lower part of the Lippincott Member of the Lost Burro Formation, southeastern California. The sharing of similar faunal elements with the Early Devonian assemblages of the Sevy Dolomite and Water Canyon Formation of Utah and Nevada, respectively, together with stratigraphic constraints on the age of the Death Valley fauna, suggest that these assemblages are age equivalent and have a late Emsian (inversus–serotinus Zones) age. The vertebrate-bearing unit of the Lippincott Member is interpreted as a channel-fill deposit laid down in an estuarine environment with low or fluctuating salinity.