Gastaldo, Robert A., Adendorff, Rose, Bamford, Marion, Labandeira, Conrad C., Neveling, Johann, and Sims, Hallie J. 2005. "Taphonomic trends of macrofloral assemblages across the Permian-Triassic boundary, Karoo Basin, South Africa." Palaios. 20 (5):479–497. https://doi.org/10.2110/palo.2004.P04-62