New Species of Ancient Chirping Giant Pill-Millipedes Discovered in Madagascar

It's a finding that may make you rethink how you look at pill bugs in your backyard. A team of researchers has discovered several new species of ancient, chirping giant pill-millipedes from Madagascar that may already be threatened.

The species that were discovered all belong to the genus Sphaeromimus, which is Latin for "small ball animal." Yet in this case, the insects aren't exactly "small." In fact, there are members that are larger than a ping-pong ball. Not only that, but these species have the largest chirping organelles of any millipede, which are probably used during mating.

One of the new species, called Sphaeromimus andrahomana, actually offers new insights into Madagascar's ecosystems thousands of years ago. While the species was found in a cave in Madagascar's southern dry spiny forest region, it's genetically a rainforest taxon. Lemur skeletons inside the cave also indicate that the area likely hosted a rainforest about 3,000 to 5,000 years ago. It's likely that the species of millipede was sheltered by the humid cave while its surroundings turned into a desert-like area.

This, in particular, is exciting for researchers. It means that some of the species are microendemics, which means that they can only be found in one tiny forest fragment a few hundred meters long and wide. For example, S. lavasoa is restricted to the Lavasoa mountain, which is covered by an isolated rainforest remnant and another new species called S. saintelucei is restricted to a fragment of the Sainte Luce littoral rainforest which is now so small that no large vertebrate species can survive in it.

Yet while these findings are intriguing, they also show that these millipedes are threatened. Because they're living in such a small area, their natural ecosystem can easily be disrupted by outside forces and lead to extinction.

"Although there are intentions to designate and manage conservation zones, the plan to protect only one large fragment may result in the extinction of some of the species if additional conservation measures aren't undertaken," said Thomas Wesener, one of the researchers, in a news release.

The findings are published in the journal ZooKeys.