Researchers uncover new millipede species under Los Angeles

By Jared Dashoff

It could be a scene from a Hollywood horror movie: NSF-funded researchers found a new species of living creatures — described as pale, eyeless and with nearly 500 legs — thriving in the soil under Los Angeles. The creature is adapted to life underground and likely never surfaces, so the more than 18 million people in the region likely don't know what lurks beneath their feet.

Array of four of the first photographs of llacme socal. The pale millipede is situated on a black background and each image shows a different level of detail. One image has a coin for size reference
Credit: Paul Marek, Department of Entomology, Virginia Tech
Photographs of living Illacme socal Shear and Marek, 2023. These photographs, the first ever of this species, shows its pale coloration, lack of eyes, short legs, and large antennae. These features are typical of animals that live under the ground and burrow in the soil substrate.

But rather than posing a threat to humanity, the species of millipede, dubbed Illacme socal in honor of its Southern California roots, serves a critical role in the area's ecosystem. Millipedes break down dying and decaying material from plants, fungi and other sources and provide key nutrients to the soil that help support new life.

Paul Marek, associate professor of systematics at Virginia Tech, discovered the new species in two different areas of greater Los Angeles. The first was in the Whiting Ranch Wilderness Park, a 2,500-acre area of rivers and woods in Orange County just south of Anaheim, a suburb of Los Angeles. A second possible specimen, a juvenile millipede, was observed in the Eaton Canyon Natural Area, just north of another suburb, Pasadena, but could not be fully identified given its relative age.

The discovery was published today in ZooKeys.

A. California live oak woodland habitat surrounded by chaparral shrubland. B. Close up of oak woodland habitat. C. Close up of habitat beneath oak canopy. D. An I. socal individual (center) encountered beneath the humus layer and embedded within the underlying soil matrix.
Credit: Paul Marek, Department of Entomology, Virginia Tech
Habitat of the millipede Illacme socal Shear and Marek, 2023 at Whiting Ranch Wilderness Park, Orange County, California. A. California live oak woodland habitat surrounded by chaparral shrubland. B. Close up of oak woodland habitat. C. Close up of habitat beneath oak canopy. D. An I. socal individual (center) encountered beneath the humus layer and embedded within the underlying soil matrix.

Work like Marek's to identify new species and place them in the evolutionary tree of life helps to describe Earth's biological diversity and shows that even in densely populated metro areas there's much diversity to discover beneath our feet. There are an estimated 4 million to 6 million arthropod species, including millipedes, living on Earth, but only about 1 million have been described to date. While specimens of l. socal were only found in these particular areas, Marek believes species likely lived in other parts of the LA-metro area before development led to habitat loss. The limited habitat makes conservation of the species more important.

"Studying and cataloging millipedes and other species that live in and feed the ground below us can help us to make informed decisions to conserve biodiversity on this planet and also help preserve the environment that humans also depend on," Marek said.

About the Author

Jared Dashoff
Jared Dashoff
Communications Specialist

Jared is a communications specialist in the Directorate for Biological Sciences at the National Science Foundation. Before joining NSF, Jared developed communications materials and strategies for organizations in a host of industries, ranging from defense to education and healthcare. His love for words and language extends beyond his professional pursuits to word puzzles and he regularly competes in crossword puzzle tournaments; he even featured in the DVD extras of a documentary on the American Crossword Puzzle Tournament.