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This is a common Pennsylvania gastropod. It strongly resembles Ananias welleri, which lived at the same time. They can be disinguished by the ridge on the outer part of the whorl, which in Worthenia tabulata is convex and nodose and in Ananias welleri is concave. The two species were the subject of a study on convergent evolution by Dr. Niles Eldredge. [Eldredge, N., 1968, Journal of Paleontology, v. 42, p. 186-196] (Length 1.5 cm.)
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