New ginkgophytes from the Upper Triassic–Lower Cretaceous of Spitsbergen and Edgeøya (Svalbard, Arctic Norway): The history of Ginkgoales on Svalbard.

摘要

Premise of research. During the ongoing investigation of Upper Triassic–Lower Cretaceous plant macrofossilsfrom Svalbard, Norway, some ginkgoalean leaf fossils were found from Carnian and Aptian deposits ofSpitsbergen and Edgeøya that represent newginkgophyte species. One newspecies is described as Baiera aquiloniasp. nov., and one ginkgophyte leaf is assigned to Ginkgoites sp. Along with the description of the new material,an overview of the presence and distribution of ginkgophytes in the high-latitude ecosystems of Svalbard throughtime is provided.Methodology. The plant macrofossils have been analyzed with transmitted-light and epifluorescence microscopy.Attempts to isolate cuticles were made.Pivotal results. The investigation resulted in the description of one species new to science, Baiera aquiloniasp. nov., and one specimen assigned to Ginkgoites sp. The presence of ginkgophytes on Svalbard changed significantlythrough time: periods of dominance and wide distribution interchanged with periods of very lowdiversity and abundance.Conclusions. Ginkgophytes were thriving in Svalbard, which was already located above 607N by the Carnian,from the Late Triassic to the Cenozoic in varying abundance and were finally extirpated, probably as a result ofdramatic climatic changes at the end of the Paleogene