Paper No. 195-8
Presentation Time: 10:00 AM
MID MESOZOIC LACEWINGS AND CENOZOIC BUTTERFLIES EVOLUTIONARILY CONVERGE
Historically the poor preservation of kalligrammatid lacewings (Order Neuroptera) has prevented knowledge of their biology. This clade of large, showy insects appeared in the fossil record 165 m.y. ago and became extinct around 110 m.y. ago. By contrast, after a 55 million-year interim, butterflies (Order Lepidoptera), appear relatively recent around 55 m.y. ago, contributing a poor fossil record but becoming one of the more important herbivore and pollinator groups in modern ecosystems. Our study of mid-Mesozoic kalligrammatid lacewings from Kazakhstan and especially Northeastern China has revealed a surprising array of several features that are evolutionarily and ecologically convergent with Cenozoic butterflies. These include wing eyespots with possible melanin centers, wing scales, elongate tubular proboscides, and similar modes of fluid feeding on seed-plant ovulate organs. To study these organisms, we prepared camera lucida drawings; macerated pollen; imaged through polarized light, epifluorescence and scanning electron microscopy; and used techniques such as energy dispersive spectrometry and time-of-flight secondary ion mass spectrometry. We found that the evolutionary developmental pattern of wing spot and eyespot absence and the presence of wing spot and five distinctive eyespot morphotypes, when mapped onto a phylogeny of Kalligrammatidae, resembled similar evolutionary patterns in modern butterflies. The mode of lacewing fluid feeding on pollen-drop-bearing gymnosperm ovulate fructifications such as bennettitaleans likely resembled those of more recent butterflies that imbibe the nectar of angiosperm flowers, indicating similar ecological roles. We suggest that the primary function of wing eyespot in arboreal kalligrammatids was predation deterrence through production of an effective startle response to ward off potential predators such as lizards, early birds and small, perching, theropod dinosaurs. The similarities between kalligrammatid lacewings and butterflies may be one of the best examples of evolutionary convergence in the insect fossil record.