German scientists at the Stuttgart Natural History Museum were leading in the discovery of a new insect order from the Lower Cretaceous of South America. The spectacular fossils were named Coxoplectoptera by their discoverers and their findings were published in a special issue on Cretaceous Insects in the scientific journal Insect Systematics & Evolution. The work group led by Dr. Arnold H. Staniczek and Dr. Günter Bechly, both experts on basal insects, determined1 that these fossils represent extinct relatives of modern mayflies(蜉蝣) . Coxoplectoptera however significantly differ from both mayflies and all other known insects in anatomy2(解剖) and mode of life. Due to the discovery of adult winged specimens3 and excellently preserved larvae4, the scientists were able to clarify the phylogenetic(系统发生的) position of these animals and presented a new hypothesis regarding the relationships of basal winged insects. Equipped with wing venation(脉络) of a mayfly, breast and wing shape of a dragonfly, and legs of a praying mantis5, these winged insects look like a patchwork6 of various animals. The peculiar7 larvae, however, are reminiscent of freshwater shrimps8. Their lifestyle turned out to be a major enigma9: Mode of embedding10 and some of their characters clearly suggest a fluvial habitat. Their unique anatomy indicates that these animals were ambush11 predators12 living partly dug in the river bed. These animals furthermore provided clues to the long-standing controversial debate of the evolutionary13 origin of the insect wing: The scientists presume that wings originated from thoracic(胸的) backplates, while leg genes14 were recruited for their developmental control.
Overall, the exciting discovery of Coxoplectoptera contributes to a better understanding of insect evolution.