LATE TRIASSIC AETOSAUR BIOCHRONOLOGY REVISITED

• Main Author: Andrew B. Heckert
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: greenlandic
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.498.4046; http://paleo.cortland.edu/globaltriassic/Bull41/16-Heckert et al (Aeto redux).pdf

Abstract—Eleven years ago Lucas and Heckert (1996) proposed five biochrons based on aetosaur genus-level occurrences in the Upper Triassic Chinle Group of the southwestern U.S.A., another for Stegomus in the eastern U.S.A., and a Greenlandic-European Aetosaurus biochron. While some have embraced this biochronological frame-work, others have challenged it on taxonomic, stratigraphic, and evolutionary grounds, while additional discoveries have further modified the underlying taxonomic framework. Here, we take this opportunity to evaluate the past decade’s progress in aetosaurian systematics and distribution to critically reevaluate the biochronological potential of aetosaurian taxa. No fewer than nine genera of aetosaurs provide biostratigraphic correlations within the Chinle Group, and five of these reliably correlate Chinle Group strata to other strata across Pangea. Thus, it is clear that aetosaurs remain robust biochronological tools for the subdivision of Late Triassic time.