Integrated Principles of Zoology 14th Edition by Cleveland Hickman, Larry Roberts, Susan Keen, Allan Larson

Exercise 4

Briefly describe characteristics of the hypothetical ancestral mollusc, and tell how each class of molluscs (Caudofoveata, Solenogastres, Monoplacophora, Polyplacophora, Scaphopoda, Gastropoda, Bivalvia, Cephalopoda) differs from the ancestral condition with respect to each of the following: shell, radula, foot, mantle cavity and gills, circulatory system, and head.