Abstract
By combining the effective ecospace with principles of constructional morphology, an evolutionary flow chart can be modeled that applies to most bivalve groups. It is speculated that some remarkable deviations from this scheme result from endosymbiosis with algae and bacteria that acted as deviators in bivalve evolution, but may also have increased the probability of their partners to become extinct. Solemyatuba nov. ichnogen. is erected for U‐tubes of presumed Solemya origin.

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