The oldest hyolithids (Cambrian Series 2, Montezuman Stage) from the Iapetan margin of Laurentia

Abstract

AbstractThe recent description of the nevadioid trilobiteBuenellus chilhoweensisWebster and Hageman, 2018 established the presence of early Cambrian Montezuman Stage (Cambrian Series 2, Stage 3) faunas in the Murray Shale of Chilhowee Mountain, Tennessee. The description recognized the oldest known age-diagnostic Cambrian trilobite from the Laurentian margin of the former Iapetus Ocean sinceBuenellusBlaker, 1988 is known otherwise only from the Sirius Passet Lagerstätte on the Innuitian margin of North Greenland. The bivalved arthropodsIsoxys chilhoweanusWalcott, 1890 andIndota tennesseensis(Resser, 1938a) have also been described from the Murray Shale, but hyolithids appear to be the dominant body fossils in terms of diversity and abundance. Although poorly preserved, the hyolithids occurring together withBuenellus chilhoweensisare described to improve understanding of the Murray Shale biota. The hyolith assemblages of the Murray Shale and Sirius Passet Lagerstätte are not closely similar, although the poor preservation of both hinders comparison.