NEOEXTINCTIONS OF MARINE-INVERTEBRATES

Historical or recent extinctions (here called neoextinctions) are rare ly reported among marine and estuarine invertebrates. Four case histor ies of neoextinctions, using gastropod mollusks (snails) as examples, are reviewed: the periwinkle Littoraria flammea (last collected < 1840 in China), the rocky shore limpet ''collisella'' edmitchelli (1861/3 in southern California), the eelgrass limpet Lottia alveus (1929 in Ma ine), and the marsh horn snail Cerithidea fuscata (1935, southern Cali fornia are all probably extinct. The central element in the demise of all four species may have been a vulnerable, extinguishable habitat. T hree considerations suggest that neoextinctions among marine invertebr ates have been generally overlooked: 1), hundreds of taxa have not bee n reported since the 18th and 19th centuries (these are treated by sys tematists as either unrecognizable, rare, or synonyms of known species ); 2), species may have become extinct prior to their description; and 3), there has been a precipitous decline in systematics, biogeography , and natural history at the end of the 20th century-leaving too few w orkers to tell the story of neoextinction in the ocean. Searches in th e literature and museums for overlooked neoextinctions would fruitfull y focus on species reported from highly impacted, urbanized coastal ha bitats-saltmarshes, estuaries, lagoons, seagrass communities, and supr alittoral (maritime) zones-habitats now largely obliterated on most co astal margins of the world.