Shishania

Genus of Cambrian molluscs

Shishania is a genus of stem-group mollusc from the Cambrian period. It contains a single species, Shishania aculeata. Shishania specimens come from the Wulongqing Formation in China, and date back to around 514 to 509 million years ago. Shishania was a flattened, bilaterally symmetrical slug-like animal with a muscular foot. It had no shell, but was covered in hollow chitinous spines. These sclerites provide a stepping stone between the solid chaetae-like chitinous sclerites of Wiwaxia and the partially hollow, biomineralized sclerites of aculiferan molluscs. This suggests the mollusc ancestor was covered in hollow chitinous sclerites that shared a common origin with annelid chaetae.

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