XVI International Botanical Congess

During the Cenomanian, there is a transition involving the rise to dominance of angiosperms. The record is well represented in a number of floras, most containing about 15-20 angiosperm species except for the Dakota Fm., which is composed of 437 species. A re-examination of angiosperm fossils from the Dakota Fm. is important for a full understanding of early angiosperm diversity. Work by Upchurch & Dilcher on the Rose Creek locality presents 20 species. Preliminary analysis of the collections in the Florida Museum of Natural History indicates that there is about 20-25 species at any localities of the Dakota Fm. Comparison of species between Courtland and Rose Creek localities indicates 25% of species overlap. The unbiased understanding of angiosperm diversity at this special period is important for us to understand the evolution of angiosperms.