1. The Contribution of Regional Variability to Beta Diversity: A Case Study of the Deep-water Marine Communities of the Middle Upper Ordovician of Eastern Laurentia Open Access Author: Perkons, Eriks Title: The Contribution of Regional Variability to Beta Diversity: A Case Study of the Deep-water Marine Communities of the Middle Upper Ordovician of Eastern Laurentia Graduate Program: Geosciences Keywords: PaleontologyPaleoecologyGeobiologyOrdovicianTrentonGradientBiofaciesBeta diversitySalonaCoburn File: Download Perkons_Thesis_Upload_2.pdf Committee Members: MARK E PATZKOWSKY, Thesis Advisor/Co-AdvisorPeter Daniel Wilf, Thesis Advisor/Co-AdvisorMichael Allan Arthur, Thesis Advisor/Co-Advisor