Object Record
Images




Metadata
Title |
Cardium sp.,Cockle (clam) Fossil, 1.5-.75 Ma |
Object Name |
Shell, Animal |
Description |
Pseudocardia densatom, cockle (clam) fossil, Miocene to Pleistocene dating from between 23.03 to .012 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 comprised of two shells sandwiched together. Larger shell on top has distinct growth rings, with sediment filling the spaces between rings. Smaller shell on underside surface also has growth rings, but are not as pronounced. Dark brown sediment fills the space between the two and anchors them together. Both shells are in varied shades of brown and beige. Surrounding sediment also contains smaller shell fragments. |
Date |
23.03 to .012 Ma |
Catalog Number |
2014.009.016 |
Collection |
3D - Biology |
Kingdom |
Animalia (Animals) |
Phylum |
Mollusca (Molluscs) |
Class |
Bivalvia (Bivalves) |
Order |
Veneroida (bivalve order) |
Family |
Cardiidae (Cockles) |
Genus |
Pseudocardia |
Species |
densatom |
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 |
USGS Emeritus Charles Powell identified on 4/17/2018. Retired Geologist Ken Lajoie identified on 4/24/2014. |
Dimensions |
H-1.875 W-2.5 D-2 inches |
Search Terms |
Fossils Shellfish Merced Formation South San Francisco |
Subjects |
Fossils Shells Shellfish Marine biology |
Credit line |
Courtesy of Marilyn & Robert Moore |