Over 200 species of freshwater and terrestrial water bears (phylum. Tardigrada) are known to occur in North America. Of these, 16 species have been collected in Louisiana. Foliose and fruticose lichens collected on 18 April 2010 in Acadia Parish, Louisiana, were stored in paper envelopes and later soaked in tap water overnight. Tardigrade specimens and eggs were extracted and mounted in polyvinyl lactophenol. The samples contained a new species of tardigrade. Minibiotus acadianus sp. n. has a buccal tube with single anterior curvature, 2 macroplacoids and 1 microplacoid. Small gibbosities are present on the fourth pair of legs, in 3 caudal rows, and in a single row at the level of the third pair of legs. Minibiotus acadianus sp. n. differs from the most similar tardigrade species, Minibiotus fallax (found in Australia and Florida), in having a shorter and wider buccal tube, a different pattern of gibbosities, and short, peg-shaped processes in addition to long, filamentous processes on the eggs. Reexamination of specimens identified as M. fallax in an earlier paper on the Tardigrada of Louisiana indicates that they are, in fact, M. acadianus sp. n., suggesting that the new species is widely distributed in Louisiana.