CARPESTELLA LACUNATA GEN. ET SP. NOV., A NEW BASAL ANGIOSPERM FLOWER FROM THE EARLY CRETACEOUS (EARLY TO MIDDLE ALBIAN) OF EASTERN NORTH AMERICA

摘要

The charcoalified fossil flower, Carpestella lacunata gen. et sp. nov., from the Early Cretaceous (Early to Middle Albian) Puddledock locality, Virginia, has affinities to early branching lineages of extant angiosperms. The flower is small and actinomorphic. It shows ～15 large basal scars, interpreted as those of tepals, and ～60 smaller, quadrangular, distal scars, interpreted as those of stamens or staminodes. Both sets of organs are spirally arranged. The gynoecium is at least partly inferior and plurilocular, with 13 carpels arranged radially around a central column to which they are fused. The gynoecium is syncarpous, but the carpel flanks are partially free, and septal slits are present. Comparisons with extant angiosperms demonstrate similarities with flowers of Nymphaeaceae (especially Nymphaea) and also Illiciaceae (Illicium). The characters of the fossil may indicate that it represents a separate, now extinct phylogenetic lineage among the earliest branching lineages of extant angiosperms. Alternatively, the presence of septal slits, which links the fossil to Nymphaeaceae, makes it possible that the fossil is an extinct taxon within this family but distinct from all extant genera.