Published online by Cambridge University Press: 20 January 2017
Investigation of snail-bearing alluvium from the Smyth Crossing site in Uvalde County, Texas, indicates that the terrestrial gastropod fauna of this area has been stable for at least 3000 yr. However, relative proportions and presence/absence variations indicate changes in the relative occurrence of preferred microhabitats of certain snails. Gastropods from an excavated soil column reveal a succession of gastropod associations in response to succession of the plant community of the site from a riverside gravel bar to an upland savannah/grassland. Human impact on the gastropods is mostly contemporary, with apparent local extirpations of some species having occurred. The recovered paleofaunas provide no evidence for regional climatic change since 3000 yr B.P.