Ptilozamites chinensis (Pteridospermopsida) from the Late Triassic of South China with considerations on its intraspecific variability and palaeoenvironmental preferences

Ptilozamites Nathorst 1878 is one of the most widespread genera of Mesozoic seed ferns, reaching its highest diversity during the Late Triassic. As a palaeogeographic and biostratigraphic marker restricted to the Late Triassic of the Southern Floristic Province in China, Ptilozamites chinensis Hsu 1950 had once been transferred to the genus Pseudoctenis Seward 1911. A detailed morphological and anatomical study of the well-preserved material col-lected from Upper Triassic sediments of South China, as well as the re-investigation of representative historical specimens demonstrate it belongs to the genus Ptilozamites. A neotype and an emended diagnosis for Ptilozamites chinensis are proposed. A comparison with the previously documented specimens of Ptilozamites chinensis sug-gests a different overall morphology during the developmental process of the plant. The paleogeographic distri-bution of Ptilozamites chinensis indicates a preference for hot and humid habitats during the Late Triassic of the Southern Floristic Province. (c) 2022 Elsevier B.V. All rights reserved.

Automated summary

Ptilozamites chinensis is a paleogeographic and biostratigraphic marker for the Late Triassic Southern Floristic Province in China. A detailed study of its morphology and anatomy confirms its classification in the genus Ptilozamites, and an emended diagnosis is proposed. Comparison with previously documented specimens reveals different overall morphology during the plant's development.