Osmunda vancouverensis sp. nov. (Osmundaceae), Permineralized Fertile Frond Segments from the Lower Cretaceous of British Columbia, Canada

The Lower Cretaceous (Valanginian to Hauterivian) Apple Bay locality onVancouver Island, British Columbia, has yielded several fragments of fertile permineralized osmundaceous pinnae. Specimens are preserved in calcareous concretions, showing both internal anatomy and allowing for the reconstruction of external morphology. Sporangia are borne laterally and clustered along terete pinna segments. They range from 550 to 650mm in diameter, with a lateral annulus that is nine to 12 cells wide and two to three cells high and is separated from the stalk by only one or two cells. Spores are spheroidal and trilete, 40-52 mm in diameter, with long laesurae and a coarsely tuberculate exospore. Some tubercles are fused, forming microrugulae. Sporangial structure and spores most closely resemble those of Osmunda L. These fossils, described as Osmunda vancouverensis sp. nov., add to our growing appreciation for the antiquity of modern Osmundaceae and underscore the potential of the numerous well-preserved fern fossils from Apple Bay to enhance our understanding of the phylogeny of Filicales.