中国科学院南京地质古生物研究所机构知识库

Premise of research. Prominently winged fruits occur in many families of angiosperms today, but they are rare and poorly documented in the mid-Cretaceous.TricalycitesNewberry ex Hollick is a widely distributed winged disseminule from the mid-Cretaceous to Upper Cretaceous sediments of the United States. However, some of the specimens previously attributed to this genus are morphologically distinct, representing a different genus. Methodology. Micro-computed tomography and scanning electron, reflected light, transmitted light, and epifluorescence microscopies were applied for the analyses of compression and impression fossils. Pivotal results. Wireroadiagen. nov. is established on the basis of triwinged fruits from the mid-Cretaceous (Cenomanian) of Alabama. The disseminules include a pedicellate, longitudinally ribbed, globose fruit body and a persistent style. Three prominent longitudinal wings with parallel sides, rounded apexes, and subparallel venation arise from the base of the fruit. The wing epidermis includes prominent trichome bases and paracytic stomatal complexes that are encircled by a ring of radially arranged cells. In addition to the wings, the type species,Wireroadia viccalliisp. nov., shows a pair of prominent antler-like branched spines arising laterally from the base of the fruit.Wireroadia major(Hollick) comb. nov. from the Late Cretaceous (Santonian) of New York, New Jersey, and Massachusetts has larger fruits that lack the branched spines. Both species ofWireroadiaare readily distinguished fromTricalycites, which has a miniscule seed body and a single trilobed wing, lacks trichome bases, and bears both paracytic and tetracytic stomata. Conclusions. Wireroadiais interpreted as an extinct genus of eudicot, readily distinguished fromTricalycites. Despite convergent similarities with fruits of Fagales and other extant orders, the more precise systematic position remains uncertain. The presence of both wings and spiny appendages indicates that dispersal might have been by animals, as well as by wind.