Object Record
Images
Metadata
Title |
Cardium sp.,Cockle (clam) Fossil, 1.5-.75 Ma |
Object Name |
Shell, Animal |
Description |
Pseudocardia densatom,cockle (clam) fossil, probably Miocene dating from between 23.03 to 5.333 million years ago commonly found at low tide in littoral (sandy and muddy bottom) or sub-littoral (open bay, muddy marine) zones. Fossil specimen has a fully preserved top and bottom shell, still connected by the ligament. Both shells are concave in shape. A fracture runs down the middle of the top shell. Area closest to the ligament is white; the remaining area is multicolored in varying shades of brown, beige and reddish brown (likely indicating the presence of iron oxide). Growth lines are easily visible. The bottom shell has a fracture that runs diagonally across the shell. Shell is multi-colored in shades of white, beige and reddish brown. Growth lines are easily visible. |
Date |
23.03 to 5.333 Ma |
Catalog Number |
2014.009.017 |
Dimensions |
H-1.375 W-2 D-1.875 inches |
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. Cardium sp. (Common Name: Cockle Shell) still thrives in the Bay Area. |
Search Terms |
Fossils Shellfish Merced Formation South San Francisco |
Subjects |
Fossils Shells Shellfish Marine biology |
Credit line |
Courtesy of Marilyn & Robert Moore |