A Probable Pollination Mode Before Angiosperms: Eurasian, Long-Proboscid Scorpionflies

College of Life Sciences, Capital Normal University, Beijing 100048, China.
Science (Impact Factor: 33.61). 11/2009; 326(5954):840-7. DOI: 10.1126/science.1178338
Source: PubMed


The head and mouthpart structures of 11 species of Eurasian scorpionflies represent three extinct and closely related families during a 62-million-year interval from the late Middle Jurassic to the late Early Cretaceous. These taxa had elongate, siphonate (tubular) proboscides and fed on ovular secretions of extinct gymnosperms. Five potential ovulate host-plant taxa co-occur with these insects: a seed fern, conifer, ginkgoopsid, pentoxylalean, and gnetalean. The presence of scorpionfly taxa suggests that siphonate proboscides fed on gymnosperm pollination drops and likely engaged in pollination mutualisms with gymnosperms during the mid-Mesozoic, long before the similar and independent coevolution of nectar-feeding flies, moths, and beetles on angiosperms. All three scorpionfly families became extinct during the later Early Cretaceous, coincident with global gymnosperm-to-angiosperm turnover.

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Available from: Alexandr P. Rasnitsyn, Oct 03, 2015
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    • "Their persistence and unique ancestry provide researchers the opportunity to gain insight into many aspects of plant evolution and biology (Norstog and Nicholls 1997). Recent evidence of ancient gymnosperminsect associations inferred from fossils of Mesozoic origin (Klavins et al. 2005; Krassilov et al. 2007; Labandeira et al. 2007; Ren et al. 2009; Peñalver et al. 2012) and cycad studies since the 1980s have changed perceptions of how early seed plants were pollinated. "
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    ABSTRACT: Premise of research. The role of specialist insects in the pollination of cycads is well established, with wind playing little to no role. Questions remain for species within the Cycas rumphii complex that have dispersed via floating seeds to islands far from mainland ancestors. One such species, Cycas micronesica, resides in habitats on the island of Guam that are exposed to trade winds that enhance the potential for wind pollination. Methodology. We examined the distance and direction of horizontal pollen movement either from microstrobili or from experimentally released pollen relative to wind direction and velocity in several different Guam cycad habitats. Wind-dispersed pollen was also captured around megasporophylls and then examined relative to wind and distance from dehiscing microstrobili. Pivotal results. Wind velocity, trap direction, and trap distance from the pollen source were the most important factors affecting pollen capture. In habitats where C. micronesica grows in the deep understory with !0.08 m/s mean wind velocities, pollen capture was near zero even at 4 m from the pollen source. In understory habitats with higher wind velocities, downwind traps captured substantial pollen up to at least ∼8 m. In open habitats where wind velocities averaged 12 m/s, some downwind traps captured significant pollen even at 32 m but with a dramatic decrease after 8 or 16 m, and upwind traps captured little pollen. Pollen capture around megasporophylls was substantial for those up to the experimental limits of ∼6 m downwind from a dehiscing microstrobilus. Conclusions. These results, along with previous studies that verified specific insect associations with reproductive organs of C. micronesica, indicate ambophily but with a stronger role for wind as a pollen vector than in previous Cycas studies. However, wind as a vector is limited to open areas or forested habitats with some exposure to winds and is not found in deep understory habitats.
    International Journal of Plant Sciences 05/2015; 176(6):000-000. DOI:10.1086/681821 · 1.53 Impact Factor
    • "The palaeoenvironment reconstructed for the Daohugou area is a volcanic region with mountain streams and lakes, the climate was humid and warm-temperate (Shih et al. 2009). This area contains a diverse insect fauna, for example, Dermaptera (Zhao et al. 2010), Neuroptera (Wang et al. 2010; Yang, Makarkin, et al. 2012), Mecoptera (Ren et al. 2009; Ren, Shih, Labandeira 2010; Wang, Labandeira, et al. 2012; Yang, Shih, et al. 2012), Odonata (Li et al. 2012; Li, Nel, et al. 2013), Trichoptera (Gao et al. 2013), Coleoptera (Chang and Ren 2008; Pan et al. 2011; Tan et al. 2012), Hemiptera (Wang and Ren 2009), Orthoptera (Gu et al. 2012), Heteroptera (Yao et al. 2012), Chresmodidae (Zhang et al. 2010), Diptera (Zhang et al. 2011), Ephemeroptera (Huang et al. 2007), Plecoptera (Liu et al. 2007), and especially many hymenopteran fossils (Gao et al. 2009; Shih et al. 2009; Liu et al. 2011; Wang, Shih, et al. 2012). "
    Li · Shih
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    ABSTRACT: Praeaulacus obtutus sp. nov., assigned to the subfamily of Praeaulacinae Rasnitsyn, 1972 in the family Praeaulacidae, Rasnitsyn, 1972, and Proapocritus bialatus sp. nov., in the family Ephialtitidae, are described and illustrated. These specimens were collected from the Middle Jurassic of Jiulongshan Formation at Daohugou in Inner Mongolia, northeastern China. Praeaulacus obtutus sp. nov. was erected by a combination of differential characters: the short and stout mesosoma, pronotum comparatively long, mesonotum not very long, the combination of pronotum and mesonotum transversely ridged and nearly arched; long hind legs. Proapocritus bialatus sp. nov. is assigned to Proapocritus Rasnitsyn, 1975 due to the following characters: wings venation complete, forewing with 1-Rs directed slightly posterodistally; 1r-rs, 2r-m, 3r-m, 2m-cu, 2A and a1-a2 present; hind wing with enclosed cell; Rs originating not basad of M + Cu fork. These findings provide new characters of these two groups and broaden the diversity of Praeaulacus and Proapocritus.
    Journal of Natural History 04/2015; 49(13-14). DOI:10.1080/00222933.2014.953223 · 0.88 Impact Factor
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    • "They were reported to live on diverse hosts such as coexisting feathered dinosaurs, pterosaurs, primitive birds and medium-sized mammals [8-10]. It has been proposed that fleas might have originated from an extinct clade of scorpionflies [8,12]. Mesozoic fleas have been organized in three families [11]. "
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    ABSTRACT: Background Fleas, the most notorious insect ectoparasites of human, dogs, cats, birds, etc., have recently been traced to its basal and primitive ancestors during the Middle Jurassic. Compared with extant fleas, these large basal fleas have many different features. Although several fossil species with transitional morphologies filled the evolutionary blank, the early evolution of these ectoparasites is still poorly known.ResultsHere we report a new flea with transitional characters, Pseudopulex tanlan sp. nov., assigned to Pseudopulicidae, from the Lower Cretaceous Yixian Formation of Liaoning Province, China. Different from the previously described pseudopulicids, P. tanlan has relatively smaller body size but lacking any ctenidia on the tibiae or body, while the male with comparatively smaller and shorter genitalia. On the other hand, P. tanlan has some characters similar to the transitional fleas of saurophthirids, such as, a small head, short compacted antennae, small pygidium and many stiff setae covering the body.Conclusions Even though other possibilities can not be ruled out, the female specimen with extremely distended abdomen suggests that it might have consumed its last meal before its demise. Compared with other reported female flea fossils, we calculate and estimate that P. tanlan sp. nov. might have consumed 0.02 milliliter (ml) of blood, which is about 15 times of the intake volume by extant fleas. These new findings further support that fleas had evolved a broad diversity by the Early Cretaceous.
    BMC Evolutionary Biology 08/2014; 14(1):168. DOI:10.1186/s12862-014-0168-1 · 3.37 Impact Factor
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