MOUTHPARTS, NECTARIVORY AND POLLINIVORY BY ADULT BRACHYCEROUS DIPTERA DURING THE MID-MESOZOIC
New occurrences from four deposits: Karatau of eastern Kazakhstan (latest Callovianearly Oxfordian), Baissa in transbaikalean Russia (early Neocomian); Yixian in northeastern China (Barremian); and Las Hoyas in Spain (Barremian) indicate that both long-proboscate and fleshy-labellate mouthpart types imbibed hidden to exposed plant fluids in floras overwhelmingly or entirely dominated by pteridiphytes and gymnosperms. Although Yixian has basal angiosperms, these flowers lacked structures consistent with nectar feeding by probing brachycerous flies. However, the presence of Classopollis pollen clumps on head regions adjacent to the proboscides of Apioceridae and especially a new genus of basal therevids, indicates that cheirolepidaceous conifersa clade with an atypical pollination systemprovided pollination drops as fluid food. Features of Classopollis pollen ultrastructure and female cone structure of related Frenelopsis suggest insect pollination. Extant analogs include pollination drop feeding by flies on all three gnetalean clades. Collectively these data provide evidence that seed-plant nectarivory and pollinivory were established on gymnosperms prior to the earliest angiosperms.