Pluricarpellatia, a nymphaealean angiosperm from the Lower Cretaceous of northern Gondwana (Crato Formation, Brazil)

TLDR: The carpel morphology clearly differs from extant Cabombaceae so that Pluricarpellatia is considered to represent an extinct member of Nymphaeales, most likely branching off early in this lineage, and may thus be the most basal member of this clade described so far.

Abstract: A fossil herbaceous angiosperm, Pluricarpellatia peltata gen. et sp. nov., is described from the Lower Cretaceous Crato Formation of northeastern Brazil. The description is based on several nearly complete specimens with roots, cordate, excentrically peltate to centrally peltate leaves, and flowering structures with in situ seeds. The seeds are smooth to verrucate and have the micropyle and hilum close together and have laminar placentation. Pluricarpellatia shares several characters with extant Nymphaeales, such as a rhizomatous growth form and simple, petiolate, peltate leaves, and laminar placentation. Similarities to Cabombaceae include an apocarpous gynoecium. However, the carpel morphology clearly differs from extant Cabombaceae so that Pluricarpellatia is considered to represent an extinct member of Nymphaeales, most likely branching off early in this lineage, and may thus be the most basal member of this clade described so far. In addition to Pluricarpellatia an unnamed nymphaealean plant (Taxon A), possibly belonging to the Nymphaeaceae, is described. During the late Aptian to earliest Albian representatives of Nymphaeales may have already developed a moderate diversity.