Researchers Discover the First True Millipede

Millipedes were named for their feet. 

The word “millipede” means thousand feet, from the Latin “mille” for thousand and “pes” for foot. But until now, no millipede has ever been described with more than 750 legs.

Researchers recently uncovered a millipede in Australia with 1,306 legs.

The tiny animals were found 60 meters (nearly 200 feet) underground in a drill hole that was originally made for mineral exploration. Named Eumilipes persephone by researchers, it has no eyes and pigment and has what is described as a “super-elognated” body.

It’s .95 millimeters wide and 95.7 millimeters long. That’s about as wide as the thickness of a credit card. It has 330 segments in its body, a cone-shaped head with large antennae, and a beak to help with eating.

“In September 2021, [study co-author] Bruno Buzatto emailed me about a millipede he discovered in Australia. He explained that one individual had more than 800 legs,” study author Paul Marek, associate professor in the department of entomology at Virginia Tech, tells Treehugger.

Buzatto is an evolutionary biologist based at Macquarie University in Sydney who also holds an adjunct research fellow position at the University of Western Australia.

"It was just a lucky find. We were looking for any subterranean fauna as part of an environmental impact assessment related with a proposal for a new mine," Buzatto tells Treehugger.

"As soon as I saw the animal in the lab (which happens several days after coming back from the field with the samples from the subterranean fauna traps), I realized that it was potentially longer (and had more legs) than the leggiest species on record so far. It was however only much later that we found out that it belonged to a different order to the other really long species, and that the two species are both adapted to subterranean life, in a typical case of convergent evolution."

The millipede was discovered in the Goldfields-Esperance region of Western Australia, an area with a strong history of mining. Because the area faces continued threats from mining, documenting this species and conserving its habitat are critically important, Marek says.

“Super-elongated millipedes such as Illacme plenipes from California (family Siphonorhinidae) with more than 800 legs were not previously known in Australia, so immediately the discovery resonated with me," Marek says.

Eight of the new millipedes were discovered in three different drill holes in troglofauna traps. Troglofauna are tiny cave-dwelling animals that live in subterranean environments. Because they were found in these deep-earth locations, it confirms their subterranean habitat and existence.

Marek explains how they actually went about measuring the millipede and counting its legs.

“Measuring the length and width involves use of a microscope eyepiece reticule (a tiny piece of glass in the eyepiece of a microscope with a miniscule measurement grid embedded within it),” he says. “Counting legs involves tallying the segments, multiplying by four (all millipedes have four legs per segment), and subtracting 14 because the last and first segments lack legs, and segments two through four have one pair of legs.”

The findings were published in the journal Scientific Reports.

About Millipedes

Although they look like bugs, millipedes aren’t insects. They’re invertebrates and are closely related to shrimp and lobsters.

There are approximately 7,000 species of millipedes around the world. They range in length from about an inch (2.5 centimeters) to more than 5 inches (13 centimeters).

Millipede bodies have segments with two sets of legs attached to the underside of each one. This is different from centipedes, which have just one set of legs per segment and those legs jut out from the sides of their bodies.

Millipedes play an important role in soil, moving slowly as they break down decaying plant matter, adding nutrients like earthworms do.

Although millipedes have lived on Earth for more than 400 million years, researchers still don’t know a lot about these small animals. But with the new 1,306-legged find, researchers are learning more.

“This is a fascinating discovery because Eumillipes persephone is a new record-setting species," Marek says.