Trilobite fauna (Wuliuan Stage, Miaolingian Series, Cambrian) of the lower Lakeview Limestone, Pend Oreille Lake, Idaho

Frederick A. Sundberg

doi:10.1017/jpa.2020.38

Abstract

AbstractThe Lakeview Limestone is one of the westernmost Cambrian exposures in the northwestern United States and occurs on the western edge of the Montania paleotopographic high. These deposits occur between the deeper water deposits to the west and carbonate banks and intracratonic basins to the east and provide critical link between the regions. A re-investigation of the Cambrian trilobite faunas from the lower portion of the Lakeview Limestone, Pend Oreille Lake, Idaho, is undertaken due to the inadequate illustrations and descriptions provided by Resser (1938a). Resser's type specimens and additional material are figured and described. The trilobite assemblages represent thePtychagnostus praecurrensZone, Wuliuan Stage, Miaolingian Series and including two new taxa:Itagnostus idahoensisn. sp., andUtia debran. sp. Because of the similarity between some species ofAmecephalusfrom the Lakeview Limestone to specimens from the Chisholm Shale, Nevada, the type specimens ofAmecephalus piochensis(Walcott, 1886) andAm.packi(Resser, 1935), Walcott's and Resser's type specimens are re-illustrate and their taxonomic problems are discussed.Utia curioWalcott, 1924 from the Spence Shale, Utah, have never been re-illustrated since Walcott (1925), these type specimens are also re-illustrated and compared toUtia debran. sp.UUID:http://zoobank.org/5ef6ee5e-bddc-4395-becf-9bcea54c679c

Highlights

Perhaps one of Charles Resser’s least cited papers is his 1938a publication on the Pend Oreille Lake fauna
The lack of detailed information of the assemblage, poor illustrations and descriptions, and conflicting age indicators (Glossopleura = Glossopleura walcotti Zone, Laurentian Delamaran Stage; Tonkinella = Ehmaniella Zone, Laurentian Topazan Stage; international Wuliuan Stage, Miaolingian Series), this paper focuses on the redescription and illustration of the trilobites and the biostratigraphy of the Lakeview Limestone
The Lakeview Limestone consists of ∼600 m of limestone, shales, and dolostones that range from the middle to upper Cambrian (Motzer, 1980; Bush and Fischer, 1981; Bush, 1989; Bush et al, 2012)

Summary

Introduction

Perhaps one of Charles Resser’s least cited papers is his 1938a publication on the Pend Oreille Lake fauna. Resser (1938a) reported on the middle Cambrian fossils from the Lakeview Limestone and Rennie Shale adjacent to Pend Oreille Lake, Idaho He named several species of brachiopods, hyolithids, and trilobites that had been collected by Edward Sampson during a survey of the Pend Oreille mining district in 1921 to 1924. The Pend Oreille locality is one of the westernmost Cambrian exposures in the northwestern United States between the deeper water deposits to the west and carbonate banks and intracratonic basins to the east (Bush et al, 2012) Given this geographic importance, the lack of detailed information of the assemblage, poor illustrations and descriptions, and conflicting age indicators (Glossopleura = Glossopleura walcotti Zone, Laurentian Delamaran Stage; Tonkinella = Ehmaniella Zone, Laurentian Topazan Stage; international Wuliuan Stage, Miaolingian Series), this paper focuses on the redescription and illustration of the trilobites and the biostratigraphy of the Lakeview Limestone. Resser’s types are re-illustrated along with new specimens and previously unreported taxa from new collections made from the lower portion of the Lakeview Limestone

Stratigraphy and depositional setting

Preservation and abundance

Materials and methods

Findings

Systematic paleontology