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The Badwater Snail (Assiminea infima) was described by Berry (1947) from Badwater Spring, Death Valley, California (U.S.A.). Hershler (1987) described the shell and soft parts of this snail in much greater detail and identified 3 new localities where it occurred in the area. Assimlnea infima typically occurs either under a salt-crust roof fringing the water's edge or on moistened riparian vegetation. Snails only occur in the vicinity of spring sources, where they are often found fully submerged. (Hershler 1987). Assiminea infima occurs at low elevations where mean annual precipitation is less than 3 cm and temperatures range from a maximum of 55 C during summer to a winter minimum of −5 C (Sada 2001 and references therein).
Hersher and Liu (2008) undertook a study to test the hypothesis that Assimina snails living in association with highly mineralized springs in the Death Valley–lower Colorado River region are relicts of the Bouse Embayment, a putative late Miocene–early Pliocene transgression of the ancestral Gulf of California along the lower Colorado River valley. Results of their biogeographic analysis, including an attempt to infer species relationships and approximate divergence times using mitochondrial DNA, appear to be incompatible with this hypothesis, suggesting instead that the Assiminea fauna of this inland area was more likely founded by coastal colonists transported on water birds than through a direct connection with the sea.