The crustacean Phreatomerus latipes,
previously thought to be a single species, is actually split into eight different species that evolved in geographically isolated springs in South Australia.
Up to 0.8 inch (2 centimeters) long, the creature--found nowhere else on Earth--relies totally on groundwater expelled from underground springs for its survival.
Many of the 850 species discovered in Australia during a recent four-year survey evolved in isolation in groundwater and tiny caves
. The animals likely took refuge underground after central and southern Australia dried out about 15 million years ago, the team said.
The new discoveries provide a "fascinating window" into past climate change and how animals evolved from surface species into subterranean animals, team member Steve Cooper, of the South Australian Museum
, said in October 2009.
Photograph courtesy Australian Centre for Evolutionary Biology and Biodiversity, University of Adelaide