Early Cambrian sponges from Vermont and Pennsylvania, the only ones described from North America

Abstract

Early Cambrian Leptomitus zitteli Walcott, 1886, is a tubular, double-walled, demo-sponge from the Parker Slate of Vermont and is one of the few intact sponges of that age known. It occurs with skeletal fragments of ?Protospongia hicksi Hinde, 1887. Hazelia walcotti (Resser and Howell, 1938) is a thin-walled, tubular sponge with crudely clustered oxeas in a thatched skeleton. It is known from the Kinzers Formation of Pennsylvania. Early occurrences of Leptomitus and Hazelia indicate that at least these two lineages had diverged by the latter part of the Early Cambrian. The impression described as Leptomitus minor by Resser and Howell (1938) lacks spicules and is not a sponge.