Conifer Cone and Dwarf Shoot Diversity in the Anisian (Middle Triassic) of Kühwiesenkopf/Monte Prà della Vacca (Dolomites, Northeastern Italy)

Abstract

Premise of research. The diversity of conifers from Kühwiesenkopf/Monte Prà della Vacca has been inferred previously on the basis of foliate branches/shoots and epidermal morphology. In this article we provide the description of the reproductive organs, which reveal a variety of forms, new morphologies and new taxa, and a comparison with other Permian–Triassic taxa, improving the knowledge of Triassic conifers. Methodology. The macromorphology, cuticles, and in situ pollen of the reproductive organs are described, and the macromorphological features are compared with those of other Permian–Triassic taxa. Pivotal results. The macro- and micromorphological analyses of the conifer reproductive organs of Kühwiesenkopf/Monte Prà della Vacca allow us to emend previously known taxa (i.e., Voltzia heterophylla, V. walchiaeformis, V. recubariensis, Pseudovoltzia edithae) and to describe new ones (i.e., cf. Voltzia sp. 1, Sidashia tridentata), providing in some cases almost complete whole-plant reconstructions. The macromorphological comparison of the Kühwiesenkopf/Monte Prà della Vacca taxa with other Permian–Triassic ones highlights the transitional character of some of them, especially P. edithae. The finding of amber anatomically connected to a V. walchiaeformis seed cone evidences the diversity of the botanical origins of the Anisian amber. Conclusions. The reproductive organs of the conifers of Kühwiesenkopf/Monte Prà della Vacca show in their morphology a mixture of characters typical of the early Permian to the Late Triassic Voltziales. Their study improves our knowledge of the reproductive biology of Anisian conifers and confirms the pivotal role of the “transitional” Triassic Voltziales that gave rise to modern groups of conifers.