The insect in the small specimen collection of Lund University in Sweden looks out of place.
“Okay, this is bullshit,” Vinicius Ferreira, an insect taxonomist and evolutionary biologist, says to himself. “It’s a joke.”
The beetle — just a tenth of an inch long and found in 1991 in Oaxaca, Mexico, among the leaves of a pine and oak forest floor at an elevation of more than 9,500 feet by naturalist Richard Baranowski — is definitely a man But one of the animal’s defining characteristics is missing: the hard forewing casing known to scientists as the elytra.
After careful examination, Dr. Ferreira described the insect this month in the Linnean Society’s Zoological Journal as a previously unknown but “rare” elytra-less species of beetle: Xenomorphon baranowskii.
“Boom. We found this strange animal. The ‘alien’ beetle,” said Dr. Ferreira, choosing a name that honored Dr. Baranwoski and also recalled the “Alien” of his favorite sci-fi movie franchise.
“We finally found one. I think it’s very exciting,” he said Michael Ivie, director of entomology at Montana State University who was not involved in the research. “It’s an amazing animal.”
“We can’t do anything yet, but until this discovery, we didn’t know there was anything else to look for,” he added.
Wings consume a lot of energy, so throughout the history of evolution, many insect species have lost the ability to fly. But there are more than half a million known species of beetle, and so far, all have at least some form of hard forewing elytra. Even in cases where it is not used for flight and is fused together, this shell-like wing covering is considered one of the keys to the beetle’s survival. This protects their soft bodies and lets them squeeze through small crevices and out of dangerous situations.
In the case of the alien beetle of Dr. Ferreira, he and his colleagues hypothesized that ceasing to fly and removing the elytra might be a protective measure to avoid being swept away by large gusts of wind at the high altitudes where they live.
Dr. also connected. Ferreira the species in a poorly understood evolutionary trend he and others studied called paedomorphosis. In this phenomenon, adult females of some beetle species retain some of their juvenile characteristics, look more like larvae and sometimes even lose their wings. The winglessness of the male Xenomorphon baranowskii resembles what is found in females of that beetle species.
But usually, male beetles use their power of flight to chase females far and wide for mating. So if paedomorphosis is already confusing in female beetles, it doesn’t make much sense that a male beetle wouldn’t have wings as an adult. “This is the most extreme example of paedomorphosis,” said Dr. Ferreira.
“It’s not good for you to be paedomorphic,” he added, because it leaves individual beetles more vulnerable to threats, and unable to get away. But, his team hypothesized, the loss of forewings and the ability to move could allow a beetle species to become more specialized and to more successfully occupy a small geographical niche.
These findings may serve as an example of how well beetles have evolved – a trait that makes them one of the most successful animals on the planet. “This is an extreme situation,” said Robert Anderson, a researcher at the Canadian Museum of Nature who was not involved in this study. “It’s clearly far out there in terms of its uniqueness.”
The description is also based on a single specimen of Xenomorphon, and although entire species of insects are often described from one-off discoveries, researchers know almost nothing about the animal. Its DNA cannot be studied, there is no data about its life history and there is no clue as to what females from this species might look like. The next step was to hike back up that Mexican mountain in hopes of finding more elytra-less beetles.
“I definitely knew it would come someday,” said Dr. Ferreira. “It’s really tricky, but everything is possible with beetles.”
