|The 165 million year old fossils of mating strashilid flies|
Then 10 new specimens of the fly species, which belong to an insect group known as the strashilids, showed something rather unusual. A team of Chinese palaeontologists led by Diying Huang from the Nanjing Institute of Geology, noticed that a number of the specimens were in pairs. A closer examination revealed that the pairs consisted of a male and a female with the grasping legs of the male wrapped around the female.
These signs suggested that the fossils were in fact of mating pairs and the grasping legs were not to hold onto the feathers or skin of a dinosaur, but evolved for copulation. What is more, the needle mouth parts did not have the specializations needed for feeding and actually appeared to be vestigial rather than functional. Finally, the mating pairs lacked wings while the separate specimens still possessed large, membranous wings. The overall image is that these creatures lived a lifestyle similar to that of a mayfly.
|Some of the single specimen, showing wings and gills, suggesting that they lived at least a partially aquatic lifestyle|