Lower Devonian conodonts from the Karheen Formation, southeastern Alaska

Abstract

Conodonts from the eastern end of Heceta Island and from a small island of the Ham Island group in the Karheen Passage, southeastern Alaska, include Ozarkodina eberleini n. sp., Eognathodus sulcatus Philip, Pandorinellina exigua philipi (Klapper), Icriodus angustoides castilianus Carls, and Pelekysgnathus klamathensis Savage. Both localities are in the Karheen Formation. The age of the faunas is considered to be early Pragian (Faunal units 5 and 6 of Klapper et al.). The early form of Eognathodus sulcatus predominates in the Heceta Island collection from Locality 1, suggesting Fauna 5, and the late form predominates in the Ham Island collection from Locality 2, suggesting Fauna 6. A middle Early Devonian age for the faunas is significant in that Locality 1 is also USGS locality 2689 which previously has yielded brachiopod and coral faunas considered to be of Late Silurian age.