Some of the earliest known flowering plants were aquatic, and groups like water lilies (Nymphaeaceae), coontails (Ceratophyllaceae), and lotuses (Nelumbonaceae) remain among the most ancient lineages alive today. Nelumbo, the lotus, is iconic for its large, round peltate leaves and striking flowers. The family represents one of the earliest eudicots (the branch of flowering plants that now dominates most modern ecosystems) to achieve global success. Fossils like Notocyamus hydrophobus from the Barremian-Aptian boundary mark the earliest known members of the group. Though only two species exist today, fossil Nelumbonaceae are found worldwide from the Late Cretaceous onward.

Fossils of Nelumbo and its extinct relatives already resemble the modern form, with broad leaves and distinctive fruit structures. However, earlier species likely lacked the showy flowers of living lotuses, instead producing more modest reproductive organs. These plants thrived in the same sorts of environments as they do today: quiet ponds, swamps, and floodplain lakes that dotted the Mesozoic landscape.