TRACKING THE INITIAL DIVERSIFICATION OF ASTERIDS: ANATOMICALLY PRESERVED CORNALEAN FRUITS FROM THE EARLY CONIACIAN (LATE CRETACEOUS) OF WESTERN NORTH AMERICA

Premise of research. The initial radiation of core eudicots (>70% angiosperm diversity) occurred during the Late Cretaceous (100.5–66 Ma). While there is strong fossil evidence for this diversification occurring throughout the Cenomanian (100.5–93.9 Ma) and Turonian (93.9–89.8 Ma), there are no unambiguous reports of the largest core eudicot clade, the asterids, from pre-Coniacian deposits (89.8–86.3 Ma). This study provides new insights into the early evolution of asterids by characterizing anatomically preserved fruits from the early Coniacian (∼89 Ma) of North America that represent three new taxa assignable to the earliest-diverging asterid order, Cornales. Methodology. Three fossil fruit types were identified within calcareous concretions from the Upper Cretaceous Eden Main locality on Vancouver Island, British Columbia. Specimens were prepared using the cellulose acetate peel technique. Pivotal results. These fruits have a thick-walled woody endocarp with germination valves, one apically attached seed per locule, and rows of vascular bundles in each septum but no central vascular bundle. The three fruit types differ from each and other cornalean fruits in endocarp size, sculpturing, and histology; thus, each type represents a new taxon: Eydeia vancouverensis sp. nov., Obamacarpa edenensis gen. et sp. nov., and Edencarpa grandis gen. et sp. nov. Conclusions. The taxa characterized in this study are contemporaneous with the previously recognized oldest cornalean, Hironoia fusiformis, from the early Coniacian of Japan. The diversity, geographic distribution, and stratigraphic age of these early cornaleans clearly indicate that the diversification of Cornales was well under way by the Coniacian.