1. (used with a sing. verb) A theory that explains the global distribution of geological phenomena such as seismicity, volcanism, continental drift, and mountain building in terms of the formation, destruction, movement, and interaction of the earth's lithospheric plates. 2. (used with a sing. or pl. verb) The dynamics of plate movement.
Despite the fact that mollusks are very susceptible to changes in their environment because of their permeable skin and soft body (often with an exoskeleton in the form of a shell), they have adapted to all of the main environments of our planetâmarine, freshwater, and terrestrial. With 41% of the 736 documented extinctions of all animal species, the number of mollusks exceeds that of any other major taxonomic group 3. 2  Most documented endangered mollusk species are non marine (they live in freshwater or terrestrial environments) 5.
Endangered Mollusks The phylum Mollusca is a very large and successful one. Because it has been around for over five hundred million years, its species have had time to exploit almost every habitat on earth; there are marine, freshwater and terrestrial species.Mollusks can be found from the mountain heights and tree branches to the mud of the ocean's abyssal depths.ecause it has been around for over five hundred million years, its species have had time to exploit almost every habitat on earth; there are marine, freshwater and terrestrial species. Mollusks can be found from the mountain heights and tree branches to the mud of the ocean's abyssal depths.