Triassic Timescale Based on Tetrapod Biostratigraphy and Biochronology

Abstract

The biochronology based on the global biostratigraphy of tetrapod fossils allows the Triassic System to be divided into eight land-vertebrate faunachrons based mainly on the first appearance datums of tetrapod genera. Temporal resolution may be improved by subdivision of these faunachrons. We note, however, that this biochronology is undermined by the use of cladotaxonomy. The Triassic tetrapod footprint biochronology has lower resolution, dividing the entire system into five footprint-based biochrons. The temporal resolution of this biochronology also may be improved through subdivision based on ichnotaxon range zones.