Non-Marine Permian Biostratigraphy and Biochronology

During the Permian, the single supercontinent Pangaea stretched from pole to pole. Early Permian glacial deposits are found in southern Gondwana. Along the sutures of Pangaea, mountain ranges towered over vast tropical lowlands. Interior areas included dry deserts where dune sands accumulated. Gypsum and halite beds document the evaporation of hot, shallow seas that formed the most extensive salt deposits in the geological record. The Permian period (251 to 299 Ma) encompasses nine ages (stages) arranged into three epochs (series). Most of the Permian marine timescale has been defined by global stratotype sections and points for the stage boundaries. This volume presents new data regarding the biostratigraphy and biochronology of the non-marine Permian and provides a basis for temporally ordering Permian geological and biotic history on land, and correlating that history to events in the marine realm.
Permian tetrapod footprints: biostratigraphy and biochronology
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Published:January 01, 2006
Abstract
Permian tetrapod footprints are known from localities in North America, South America, Europe and Africa. These footprints comprise four ichnofacies, the Chelichnus ichnofacies from aeolianites and the Batrachichnus, Brontopodus and Characichnos ichnofacies from water-laid (mostly red-bed) strata. Permian track assemblages of the Chelichnus ichnofacies are of uniform ichnogeneric composition and low diversity, range in age from Early to Late Permian, and thus are of no biostratigraphic significance. Footprints of the Batrachichnus and Brontopodus ichnofacies represent two biostratigraphically distinct assemblages: (1) Early Permian assemblages characterized by Amphisauropus, Batrachichnus, Dimetropus, Dromopus, Hyloidichnus, Limnopus and Varanopus; and (2) Middle to Late Permian assemblages characterized by Brontopus, Dicynodontipus, Lunaepes, Pachypes, Planipes, and/or Rhynchosauroides. Few Permian footprint assemblages are demonstrably of Middle Permian (Guadalupian) age, and there is a global gap in the footprint record equivalent to at least Roadian time. Permian tetrapod footprints represent only two biostratigraphically distinct assemblages, an Early Permian pelycosaur assemblage and a Middle to Late Permian therapsid assemblage. Therefore, footprints provide a global Permian biochronology of only two time intervals, much less than the ten time intervals that can be distinguished with tetrapod body fossils.