Illacme plenipes

A female with 662 legs.

Illacme plenipes is a millipede that has the most legs within this superclass. The specimen with the most legs had counted 750 The species is endemic and only from three localities in the northwestern foothills of the Gabilan Range in San Benito County in California, situated less than 4.5 km apart. She is the only member of the family Siphonorhinidae in the Western Hemisphere.

The first time was in 1926 Illacme plenipes found. The exact location is not known, the first describer Cook and Loomis write 1928

"A short distance after crossing the divide in between Salinas and San Juan Bautista ... in a small valley of a northern slope wooded with oaks, under a rather large stone"

" A short distance after crossing the watershed between Salinas and San Juan Bautista ... a hillside with oak north slope of a small valley, under a pretty big rock "

The discovery in the field remained unique until 2005, from museums and natural history collections are only 17 copies known. In 2005, in California an additional twelve specimens, four males, three females and five cubs discovered. The females had at least 660 feet, the males of maximum 402 The female specimens with up to 171 body segments were present up to 33.2 mm long and 0.5 mm wide. The male Illacme plenipes were maximum 16.15 mm long and had up to 105 segments. The head of research, Paul Marek, now demanded to put the 0.8 -square-kilometer area under protection in order to preserve the rediscovered species from extinction.