|Description||Lucinoma annulata, ringed lucine 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. Fossil specimen is mostly intact, with top and bottom shell still attached at ligament. Specimen is light brown in hue, with darker brown sediment exposed between shells. Growth rings are easily visible along the outer edges of top shell. Bottom shell has reddish-hued patches scattered throughout, likely indicating the presence of iron oxide.|
|Object Name||Shell, Animal|
|Collection||3D - Paleontology|
|Title||Lucinoma annulata, Ringed Lucine Fossil, 1.5-.75 Ma|
|Date||1.5 - .75 Ma|
|Order||Veneroida (bivalve order)|
|Family||Lucinidae (Saltwater clams)|
|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.|
Retired Geologist Ken Lajoie identified on 4/24/2014.
Lucinoma annulata (Common name: Ringed Lucine) are nearly symmetrically round, with a point in the center. Shells feature ridged rings, which are added annually. This species still thrives in the Bay Area.
|Dimensions||H-1.5 W-2.75 D-2.875 inches|
South San Francisco