Dinosaurs were not clumsy predators, they had developed elaborate mating rituals which would put peacocks to shame.
British researchers working alongside their Australian counterparts have discovered that prehistoric pterosaurs evolved elaborate headcrests to attract the best mates and pelycosaurs developed fantastic sails along their backs to oust sexual competitors.
The exact reason for the exaggerated crests and sails found in many fossil animals has been controversial and many scientists have speculated that these helped regulate the animals’ body temperature, or in the case of the pterosaurs, that they helped the reptiles to steer when in flight.
The study by scientists from the Universities of Hull and Portsmouth in the UK and Western Australia suggests that the elaborate crests and sails became so grand because of sexual competition: bigger crests and sails were more attractive to prospective mates, so they became more exaggerated over successive generations. Some pterosaurs had crests five times bigger than their skulls, according to the study published in the latest edition of The American Naturalist.
The researchers used the laws of physics to predict the scaling relationships. Animal metabolism — the process behind heat generation — can be plotted against body size.
“One of the few things that haven’t changed over the last 300 million years are the laws of physics, so it has been good to use those laws to understand what might really be driving the evolution of these big crests and sails,” Dr Stuart Humphries from the University of Hull said. The researchers found that in each case the scaling of the crests of the sails were too extreme to have a dedicated body temperature control function.
“Pterosaurs put even more effort into attracting a mate than peacocks whose large feathers are considered the most elaborate development of sexual selection in the modern day. Peacocks shed their fantastic plumage each year, so it’s only a burden some of the time, but pterosaurs had to carry their crest around all the time,” Dr Dave Martill from the University of Portsmouth added.