Aucella, genus of clams characteristically found as fossils in marine rocks of the Jurassic Period (between about 176 million and 146 million years old). The shell has a distinctive teardrop shape and is ornamented with a concentric pattern of ribs; the apex of one valve (shell half) is often curved over the other. A distinctive and commonly found Jurassic species is Aucella piochii.

This article was most recently revised and updated by John P. Rafferty.
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