in having a nexine consisting of multiple foliations rather than fused granules, plus an unusually thick tectum overlying a thin granular layer. TEM observations confirm that two species of Duguetia have a highly reduced exine consisting a probable remnants of the tectum. Cladograms confirm a trend for exine reduction in the uvarioids, with the spines of Pachypodanthium derived from tectal verrucae, as in Letestudoxa and Duguetia. Radiation of the uvarioids was apparently centered in Africa and South America when the South Atlantic was narrower than it is today.