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Mollusca

Mollusca

Overview

Phylum mollusca includes clams, snails, squid along with their shelled relatives, nautilids and ammonites. Primary characteristics include bilateral symmetry, a complete digestive tract with organ systems, and most have either an external or internal calcareous shell. Molluscs inhabit a range of environments from marine, freshwater, to terrestrial and have a variety of feeding modes including deposit feeders, filter feeders, herbivores, detritivores, and predators.

Classes of Mollusca present in the Cretaceous of the Western Interior Seaway