Devonian filter-feeding sharks

Abstract

Upper Frasnian rocks of Utah and Nevada yielded several multicuspid, low-crowned shark teeth. It is proposed that they were used mainly for filtering food from water. Two new chondrichthyan species bearing such teeth were distinguished: a choebodontid Diademodus utahensis sp. nov., with up to 17 very delicate cusps in the tooth-crown; and a cladodont of uncertain systematic position, Lesnilomia sandbergi gen. et sp. nov., also knownf rom the upper Frasnian of Moravia.