Evolution and zoogeography of the invertebrate cave faunas of the Driftless Area of the Upper Mississippi River Valley of Iowa, Minnesota, Wisconsin, and Illinois, USA

Sixteen troglobitic species are known: 2 flatworms, 2 amphipods, 1 isopod, 4 spiders, 1 mite, and 6 collembolans. The terrestrial troglobite fauna probably represents cave invasion and isolation following Early Pleistocene glaciation, and demonstrates that the caves were habitable while the region was at the margin of Late Pleistocene glaciations. The groundwater troglobite fauna may have survived in situ while the region was covered by glacial ice in the Early Pleistocene. The troglophile fauna consists of at least 78 species, and these species may or may not have come into the region since the Wisconsinan glaciation recession. The presence of troglophile species in a particular cave is highly sporadic. -from Author