Discussion of “Permian—Triassic vertebrate footprints from South Africa: Ichnotaxonomy, producers and biostratigraphy through two major faunal crises” by Marchetti, L., Klein, H., Buchwitz, M., Ronchi, A., Smith, R.M.H., DeKlerk, W.J., Sciscio, L., and Groenewald, G.H. (2019)

Abstract

A newly devised tripartite subdivision of the Karoo Basin, South Africa, is based on a number of vertebrate-trackways spanning the Middle Permian (Wordian/Capitanian) to Lower Triassic (reportedly Induan) rocks of the Beaufort Formation. The youngest Footprint Assemblage (FA III) is reported to occur in the lowermost Triassic rocks of the Palingkloof Member. One collection site from which seven trackways are reported, Bethel farm, is a classic South African locality where some authors place the end-Permian extinction event and, coincidentally, the vertebrate-based terrestrial Permian—Triassic Boundary. Published GPS coordinates for the Bethel farm site, though, indicate that these trackways originate from exposures of the Burgersdorp Formation near the town of Aliwal North. Outcrops here are assigned to the Cynognathus Assemblage Zone, and indicate a Middle Triassic age assignment. In addition, we caution the use of any small temporally or spatially restricted dataset, which is of severely limited utility, in making broad generalizations about paleoenvironmental or paleoecological interpretations.