Museum Homepage

The San Mateo County Historical Association
Online Collections Database

The mission of the San Mateo County Historical Association is to inspire wonder and discovery
of the cultural and natural history of San Mateo County.

Object Record

  • Email This Page
  • Send Feedback
Catalog Number 2014.009.033
Description Pecten sp., scallop 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. Specimen is of a scallop fossil embedded in sediment. Ridges of scallop shell are defined and easily visible, with spots of sediment between ridges. Overall reddish-brown hue, likely indicating the presence of iron oxide. Underside surface is also reddish brown overall. Possible worm castings and other shell fragments are visible in underlying sediment.
Object Name Shell, Animal
Collection 3D - Paleontology
Title Pecten sp., Scallop Fossil, 1.5-.75 Ma
Date 1.5 - .75 Ma
Kingdom Animalia (Animals)
Phylum Mollusca (Molluscs)
Class Bivalvia (Bivalves)
Order Ostreoida (Oysters and bivalves)
Family Pectinidae (Scallops)
Genus Pecten
Species sp.
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.
Dimensions H-0.75 W-1.625 D-1.25 inches
Search Terms Fossils
Merced Formation
South San Francisco
Subjects Fossils
Marine biology