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The mission of the San Mateo County Historical Association is to inspire wonder and discovery
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Object Record

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Catalog Number 2014.009.039
Description Panopea generosa, geoduck clam fossil dating from between 1.5 million years ago to .75 million years ago commonly found at low tide in littoral (sandy and muddy bottom) or sub-littoral (open bay, muddy marine) zones. Partial specimen of a geoduck clam embedded in sediment. Cream-colored shell has visible growth rings. Surrounding sediment is reddish in hue, likely indicating the presence of iron oxide. White shell fragments. likely from another clam, are also visible.
Object Name Shell, Animal
Collection 3D - Paleontology
Title Panopea generosa, Geoduck Clam Fossil, 1.5-.75 Ma
Date 1.5 - .75 Ma
Kingdom Animalia (Animals)
Phylum Mollusca (Molluscs)
Class Bivalvia (Bivalves)
Order Myoida (Saltwater clams)
Family Hiatellidae (Small saltwater clams)
Genus Panopea
Species generosa
Inscription Text none
Provenance Fossils taken from Merced Formation collected at Westborough Boulevard at Highway 280 in the late 1970s or early 1980s. (See Yancey 1978, Fig. 2: Artifacts taken from E Stratified Section/D-5929). Most specimens (especially clams) in this collection are not extinct and can still be found in the Bay Area.
Notes Retired Geologist Ken Lajoie identified on 4/8/2014.
Panopea generosa (Common name: Geoduck Clam) still thrives in the Bay Area.
Dimensions H-0.75 W-1.5 D-0.875 inches
Search Terms Fossils
Merced Formation
South San Francisco
Subjects Fossils
Marine biology