Scientists from Yale University and the Smithsonian Institution in the United States have discovered a prehistoric flightless Jamaican bird that used its club-like wings as weapons. Skeletons of the chicken-sized Xenicibis xympithecus were found in the Red Hills Fissure cave deposits in Saint Andrew, Jamaica. Storrs Olson, from the Smithsonian, was one of the scientists who first identified Xenicibis xympithecus in the 1970s.
Xenicibis was a relative of the ibis and is only known to have inhabited this island; it may have survived until less than 10,000 years ago. It was similar to other members of the ibis family apart from its wings, which contained a metacarpus (hand bone) that had evolved into powerful club-like weapons and a much larger breastbone and longer wings than most flightless birds. The extended hand bones allowed the wings to function in combat as a jointed club or flail. These boney bludgeons carried by Xenicibis xympithecus are unlike anything else known in the bird world – or in mammals, reptiles or amphibians.
Yale’s Nicholas Longrich, who led a study of recently discovered partial Xenicibis skeletons, said, “When I first saw it, I assumed it was some sort of deformity. No-one could believe it was actually that bizarre. That was our first clue that the wings were still being used for something.” He added that “No animal has ever evolved anything quite like this. [. . .] We don’t know of any other species that uses its body like a flail. It’s the most specialized weaponry of any bird I’ve ever seen.” Longrich explained that although they are not sure how they would have used these clubs, the built-in weapons may have been used to defend themselves and to protect eggs and young against predators. “We do know that modern ibises grab each other by the beak and pound away with their wings,” he added. Another unusual characteristic of the bird is that it became flightless despite the presence of a number of predators, including the Jamaican yellow boa, a small extinct monkey, and more than a dozen birds of prey.
The BBC reports that “A number of other birds are known to fight by whacking each other with their wings—including swans, who will also protect their young this way. Some, including screamers, lapwings, and spur-winged goose, have evolved spurs to increase the damage they can wreak. The extinct solitaire from the Indian Ocean island of Rodrigues—a cousin of the dodo—had bony growths colloquially known as ‘musketballs’ on their wings, which appear to have served the same purpose.
For full articles, see http://www.caribbeannewsnow.com/headline-Scientists-discover-prehistoric-Jamaica-%27ninja%27-bird-4324.html and http://www.bbc.co.uk/news/science-environment-12115776
See Proceedings of the Royal Society of Biological Studies at http://rspb.royalsocietypublishing.org/