MOLLUSCAN PALEOBIOLOGY OF THE MIOCENE WIMER FORMATION, DEL NORTE COUNTY, CALIFORNIA
1974; Cambridge University Press; Volume: 48; Issue: 6 Linguagem: Inglês
ISSN
1937-2337
Autores Tópico(s)Marine and coastal plant biology
ResumoThe upper Miocene Wimer Formation is a thin, fine-grained terrace deposit, containing 15 species of bivalves and 15 species of gastropods. Each species has a unique distribution, measured by areal trends in density, articulation, and breakage, with an over- all pattern suggesting only minor sedimentary disturbance of the fauna. Present are two communities dominated by 1) the bivalves Cryptomya californica, Macoma nasuta, and a bernardinid? species, and 2) the bivalves Macoma balthica and Mya arenaria. They indi- cate a protected coastal mudflat environment of intertidal or very shallow subtidal depth; the landward Macoma balthica Community may represent brackish conditions. The communities are part of a biogeographic province occupying a temperate climatic area. Preserved levels of population, community, and province organization are like those of western North American marine faunas today.
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