Divergence & Distribution. The distinctive fruits (with associated leaves) of Ceratophyllum are known from the Aptian and Albian onwards and are widely distributed in the Caenozoic (see Dilcher & Wang 2009; Friis et al. 2011 for references). Dilcher and Wang (2009) describe Donlesia, from deposits in Kansas of the end-Albian age some 100 m.y.a., a plant that they think may be sister to Ceratophyllum; note that it has a basal ovule, not an apical ovule as in extant Ceratophyllum