The U.S. Fish and Wildlife Service says a small snail native to Arkansas and Missouri is now presumed extinct.
The Ozark pyrg was originally found more than 100 years ago in the White River near Cotter, Arkansas, and in the North Fork White River near Norfork, Arkansas, extending into Missouri. But officials say the snail hasn't been confirmed in surveys since 1915.
The Fish and Wildlife Service reports that scientists believe construction of the Norfork Dam and the Beaver Fork Dam in the 1940s likely played a role in the snail's demise. Officials say the snail likely needed shallow, flowing water to survive and the dams drastically changed its habitat.
Officials say the Ozark pyrg will no longer be listed under the Endangered Species Act following a review that began several years ago.