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Holectypus
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Sea otter (Enhydra lutris), also called great sea otter, rare, completely marine otter of the northern Pacific, usually found in kelp beds. Floats on back. Looks like sea otter laughing. saltwater otters
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Cretaceous Period
Jurassic Period
echinoid
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Holectypus

fossil echinoderm genus
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Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree....
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History

Holectypus, genus of extinct echinoids, animals much like the modern sea urchins and sand dollars, found as fossils exclusively in marine rocks of Jurassic to Cretaceous age (between 200 million and 65.5 million years ago). Holectypus was bun shaped with a flat bottom and arched back.

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