The Ladinian Flora of the Dolomites: palaeoenvironmental and palaeoclimatic considerations

The study of several plant fossils from the Ladinian of the Dolomites, that either had been described a long time ago or had never been described at all, has led to a revision of this flora. The Ladinian flora now con-sists of the following taxa: Annalepis zeilleri (Lycophyta), Equisetites arenaceus (Sphenophyta), Cladophlebis leuthardtii, C. ruetimeyeri, Neuropteridium elegans, Scolopendrites sp., Gordonopteris lorigae (Pteridophyta), Ptilozamites heeri (Pteridospermae), Bjuvia dolomitica, Dioonitocarpidium moroderi, Pterophyllum jaegeri, ?Pterophyllum sp., Sphenozamites wengensis, Sphenozamites cf. bronnii, Taeniopteris sp. (Cycadophyta), Voltzia dolomitica, V. ladinica, V. pragsensis, V. zoldana, Voltzia sp., Pelourdea vogesiaca und Elatocladus sp. (Coniferophyta). The flora, and especially the large number of specimens housed in the Natural History Museum at Bolzano (I), indicates a dominance of conifers over (in this sequence) seedferns, cycads, ferns and horsetails. Several factors may have caused this: climatic (an arid climate on the mainland), edaphic (immature soil) or tapho-nomic (caused by selection during transport). Quantitative palynological analyses of three localities (Ritberg near Wengen, and Seewald and Innerkohlbach near Prags, indicate a generally warm and humid climate. The dominance of the conifers and seedferns may, therefore, have been caused by their larger resistance during transport rather than by climatic factors. Ladinian palaeoclimatic reconstructions and the plant fossils studies indicate that during the late Ladinian the Dolomites consisted of carbonate or volcanic islands of various sizes, which were covered with several biotopes: coastal and ‚hinterland‘; the latter divided into a more humid and a more arid zone.