New Early Devonian conodont species of central Nevada

Icriodus nevadensis, I. trojani and I. n. sp. O are biostratigraphically useful new species in the upper part of Lower Devonian sequences of central Nevada, an area to which they appear to have been restricted according to a recent review of Devonian conodont distribution. Polygnathus kendalli n. sp. is limited to the serotinus Zone, near the top of the Lower Devonian, and occurs in Nevada, Washington and the Canadian Arctic Islands. Evidence from statistical analysis of the Nevada samples from seven localities supports the contention that platform (I) elements of Icriodus were associated with simple cones of acodinan type in a multielement apparatus in the Early Devonian.