TAXON 56 (3) • August 2007: 663-695 Labandeira & al. • Pollination and Mesozoic gymnosperms Pollination drops, pollen, and insect pollination of Mesozoic gymnosperms Conrad C. Labandeira", Jif í Kvacek' & Mikhail B. Mostovski' ' ' ' Department of Paleobiology, P.O. Box 37012 (MRC-121), National Museum of Natural History, Smithsonian Institution, Washington, D.C. 20013-7012, U.S.A.
[email protected] (author for correspondence) ^ Department of Entomology, University of Maryland, College Park, Maryland 20742, U.S.A. ^ Department of Palaeontology, National Museum, Václavské nám. 68, Prague I, Czech Republic •* Natal Museum, Private Bag 9070, Pietermaritzburg 3200, South Africa ^ School of Biological and Conservation Sciences, University of KwaZulu-Natal, Private BagXOl, Scottsville, 3209 South Africa '' Paleontological Institute, Russian Academy of Sciences, 123 Profsoyuznaya Str., Moscow, 117997 Russia Recent focus on plant-insect associations during the angiosperm radiation from the last 30 million years of the Early Cretaceous has inadvertently de-emphasized a similar but earlier diversification that occurred among gymnosperms. The existence of gymnosperm-insect associations during the preangiospermous Mesozoic is evidenced by mouthparts capable of reaching and imbibing pollination drops or similar fluids, availability of pollen types consistent with entomophily, and opportunities for related consumption of pollen, seeds, and repro- ductively associated tissues in major seed-plant groups, namely seed ferns, conifers, cycads, bennettitaleans, and gnetaleans. Based on stereotypical plant damage, head-adherent pollen, gut contents, wing structure, mouthpart morphology and insect damage to plant reproductive organs, the likely nectarivores, pollinivores and pollinators were orthopterans, phasmatodeans, webspinners, sawf lies and wasps, moths, beetles, mecopteroids, and true flies. These associations are ranked from possible to probable although the last three insect clades provide the strongest evidence for pollinator activity.