How did now-extinct species court and mate? It’s generally a mystery but, every now and then, a chance discovery reveals all.
Amber: pretty jewellery, the cause of ultimate destruction in Jurassic Park and the prism through which us voyeurs view 100m-year-old insect reproduction.
The discovery of three male damselflies, perfectly preserved in amber and dating back to the Cretaceous era, has given scientists an opportunistic look at how these long-extinct insects sought partners to mate with.
A basic explanation? Females just couldn’t get enough of males’ sexy legs.
Dr Zheng Daran and Prof Wang Bo from the Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences described the damselflies in a recent paper in Nature, with the species named Yijenplatycnemis huangi.
Claiming a “suggestive” approach from the male damselflies came from their spectacular, extremely expanded, pod-like tibiae, this discovery provides one of the few examples of courtship behaviour from the age of the dinosaurs.
Larger than today’s damselflies, Y huangi’s legs are dotted with eye-shaped markings, which could well have provided some form of protection for the species.
However, Daran and Bo believe it has more to do with reproduction, setting today’s damselflies entirely apart from its ancestor. The reason for this is due to the excellent eyesight that the species enjoys.
Such markings would therefore act as a visual cue to females. Legs of this exaggerated size are very uncommon in this area, so the discovery is an eye-opener to scientists working in the field.
Modern damselflies do wave their legs to attract females, though this plays just a small role in the courtship.
Since the study has been published, other scientists have proposed various theories around Y huangi’s existence and eventual disappearance.
For example, National Geographic dragonfly expert Melissa Sanchez Herrera suggests that the Cretaceous species’ larger legs became a hindrance as they could have attracted predators, too.
In addition, the large legs would have made flying slower and less efficient for the males, with more nimble rivals surviving the 100m years between the reign of this showy trio and today’s smaller species.