title: Long-Proboscid Flies as Pollinators of Cretaceous Gymnosperms.
abstract: The great evolutionary success of angiosperms has traditionally been explained, in part, by the partnership of these plants with insect pollinators. The main approach to understanding the origins of this pervasive relationship has been study of the pollinators of living cycads, gnetaleans, and basal angiosperms. Among the most morphologically specialized living pollinators are diverse, long-proboscid flies. Early such flies include the brachyceran family Zhangsolvidae, previously known only as compression fossils from the Early Cretaceous of China and Brazil. It belongs to the infraorder Stratiomyomorpha, a group that includes the flower-visiting families Xylomyidae and Stratiomyidae. New zhangsolvid specimens in amber from Spain (ca. 105 mega-annum [Ma]) and Myanmar (100 Ma) reveal a detailed proboscis structure adapted to nectivory. Pollen clumped on a specimen from Spain is Exesipollenites, attributed to a Mesozoic gymnosperm, most likely the Bennettitales. Late Mesozoic scorpionflies with a long proboscis have been proposed as specialized pollinators of various extinct gymnosperms, but pollen has never been observed on or in their bodies. The new discovery is a very rare co-occurrence of pollen with its insect vector and provides substantiating evidence that other long-proboscid Mesozoic insects were gymnosperm pollinators. Evidence is thus now gathering that visitors and probable pollinators of early anthophytes, or seed plants, involved some insects with highly specialized morphological adaptations, which has consequences for interpreting the reproductive modes of Mesozoic gymnosperms and the significance of insect pollination in angiosperm success.
authors.affiliation: Museo Geominero, Instituto Geológico y Minero de España, Madrid 28003, Spain. Electronic address: e.penalver@igme.es.
authors.forename: Enrique
authors.initials: E
authors.lastname: Peñalver
authors.affiliation: Departamento de Zoología y Antropología Física, Facultad de Biología, Universidad Complutense, Madrid 28040, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Arillo
authors.affiliation: Museum of Comparative Zoology, Harvard University, Cambridge, MA 02138, USA.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Pérez-de la Fuente
authors.affiliation: Institute of Biotechnology, Cornell University, Ithaca, NY 14853, USA.
authors.forename: Mark L
authors.initials: ML
authors.lastname: Riccio
authors.affiliation: Departament d'Estratigrafia, Paleontologia i Geociències Marines, Facultat de Geologia, Universitat de Barcelona, Barcelona 08028, Spain.
authors.forename: Xavier
authors.initials: X
authors.lastname: Delclòs
authors.affiliation: Museo Geominero, Instituto Geológico y Minero de España, Madrid 28003, Spain.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Barrón
authors.affiliation: Division of Invertebrate Zoology, American Museum of Natural History, New York, NY 10021, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Grimaldi
mesh_terms: D018647:Amber; D000818:Animals; D032462:Cycadopsida / Q000502:physiology*; D004175:Diptera / Q000502:physiology* / Q000648:ultrastructure; D005580:Fossils / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D002052:Myanmar; D054817:Pollination; D013030:Spain
chemical_list: D018647:Amber