Fossil evidence of water lilies (Nymphaeales) in the Early Cretaceous

Phylogenetic analyses have identified the water lilies (Nymphaeales: Cabomb aceae and Nymphaeaceae), together with four other small groups of flowering plants (the 'ANITA clades': Amborellaceae, Illiciales, Trimeniaceae, Austr obaileyaceae), as the first diverging lineages from the main branch of the angiosperm phylogenetic tree(1-4), but evidence of these groups in the earl iest phases of the angiosperm fossil record has remained elusive. Here we r eport the earliest unequivocal evidence, based on fossil floral structures and associated pollen, of fossil plants related to members of the ANITA cla des. This extends the history of the water lilies (Nymphaeales) back to the Early Cretaceous (125-115 million years) and into the oldest fossil assemb lages that contain unequivocal angiosperm stamens and carpels. This discove ry adds to the growing congruence between results from molecular-based anal yses of relationships among angiosperms and the palaeobotanical record. It is also consistent with previous observations that the flowers of early ang iosperms were generally very small(5) compared with those of their living r elatives.