Taxodiaceous Pollen Cones from the Early Tertiary of British Columbia, Canada

Abstract

Two permineralized conifer pollen cones have been identified from the Appian Way locality on the east coast of Vancouver Island, British Columbia. These cones, found in marine calcareous nodules with invertebrates, are Eocene in age and have been studied with the cellulose acetate peel technique. Cones are small, terminal, and globose, with helically arranged subtending leaves, ensheathing leaves, microsporophylls, and pollen sacs with enclosed pollen grains. Peltate microsporophylls have a distal lamina with three abaxial pollen sacs. Pollen grains are small, subspherical, nonsaccate, and papillate, with a distal leptoma and proximal orbicules. Phyllotaxy of subtending leaves and microsporophylls, number of pollen sacs per microsporophyll, and ultrastructure of pollen grains are similar to those of the taxodiaceous Cupressaceae. These cones have closest similarities to Athrotaxis, Cunninghamia, Sequoia, Sequoiadendron, Taiwania, the extinct Sewardiodendron laxum (sensu Yao et al.), and Athrotaxites berryi. However, they have a combination of characters that make these cones unique among taxodiaceous conifers. Therefore, a new genus and species are described as Homalcoia littoralis Hernandez‐Castillo, Stockey et Beard. These cones show a novel combination of characters within the Cupressaceae that extends our understanding of the family and shows the presence of another extinct taxodiaceous genus in the North American Eocene.