title: False Blister Beetles and the Expansion of Gymnosperm-Insect Pollination Modes before Angiosperm Dominance.
abstract: During the mid-Cretaceous, angiosperms diversified from several nondiverse lineages to their current global domination [1], replacing earlier gymnosperm lineages [2]. Several hypotheses explain this extensive radiation [3], one of which involves proliferation of insect pollinator associations in the transition from gymnosperm to angiosperm dominance. However, most evidence supports gymnosperm-insect pollinator associations, buttressed by direct evidence of pollen on insect bodies, currently established for four groups: Thysanoptera (thrips), Neuroptera (lacewings), Diptera (flies), and now Coleoptera (beetles). Each group represents a distinctive pollination mode linked to a unique mouthpart type and feeding guild [4-9]. Extensive indirect evidence, based on specialized head and mouthpart morphology, is present for one of these pollinator types, the long-proboscid pollination mode [10], representing minimally ten family-level lineages of Neuroptera, Mecoptera (scorpionflies), and Diptera [8, 10, 11]. A recurring feature uniting these pollinator modes is host associations with ginkgoalean, cycad, conifer, and bennettitalean gymnosperms. Pollinator lineages bearing these pollination modes were categorized into four evolutionary cohorts during the 35-million-year-long angiosperm radiation, each defined by its host-plant associations (gymnosperm or angiosperm) and evolutionary pattern (extinction, continuation, or origination) during this interval [12]. Here, we provide the first direct evidence for one cohort, exemplified by the beetle Darwinylus marcosi, family Oedemeridae (false blister beetles), that had an earlier gymnosperm (most likely cycad) host association, later transitioning onto angiosperms [13]. This association constitutes one of four patterns explaining the plateau of family-level plant lineages generally and pollinating insects specifically during the mid-Cretaceous angiosperm radiation [12].
authors.affiliation: Departament de Ciències Agràries i del Medi Natural, Universitat Jaume I (UJI), Campus del Riu Sec, Castelló de la Plana 12071, Spain; Departament de Dinàmica de la Terra i de l'Oceà, Facultat de Ciències de la Terra, Universitat de Barcelona, Barcelona 08071, Spain. Electronic address: daperce@gmail.com.
authors.forename: David
authors.initials: D
authors.lastname: Peris
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: Museo Geominero, Instituto Geológico y Minero de España, Madrid 28003, Spain.
authors.forename: Enrique
authors.initials: E
authors.lastname: Peñalver
authors.affiliation: Departament de Dinàmica de la Terra i de l'Oceà, Facultat de Ciències de la Terra, Universitat de Barcelona, Barcelona 08071, Spain; Institut de Recerca de la Biodiversitat, Universitat de Barcelona, Barcelona 08071, 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: Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, P.O. Box 37012, Washington, DC 20013, USA; Department of Entomology and Behavior, Ecology, Evolution, and Systematics Program, University of Maryland, College Park, MD 20742, USA; College of Life Sciences, Capital Normal University, Beijing 100048, China. Electronic address: labandec@si.edu.
authors.forename: Conrad C
authors.initials: CC
authors.lastname: Labandeira
mesh_terms: D000818:Animals; D005075:Biological Evolution; D001517:Coleoptera / Q000033:anatomy & histology* / Q000502:physiology; D032462:Cycadopsida / Q000502:physiology*; D005580:Fossils / Q000033:anatomy & histology*; D011058:Pollen / Q000033:anatomy & histology; D054817:Pollination
keywords: Coleoptera; angiosperm; evolutionary biology; fossil; gymnosperm; host shift; mouthparts; paleoecology; plant-insect interactions; pollination