Some species also eject ink from this funnel to aid in escape from predators. The ectocochliates have an external chamber shell, while the endocochliates have a much simpler looking internal shell. The cephalopods date back to the Upper Cambrian Period. They are the second highest class of invertebrates in terms of diversity behind the insects. They live in terrestrial, freshwater, and marine environments.
Most species have a coiled shell, symmetrical cap, or no shell at all.
For more information on the phylum Mollusca, see the Ammonite catalog and the Champlain Sea pages. All rights reserved.