| Oysters I collected from exposures of the middle Eocene Coldwater Sandstone (dated by magnetostratigraphy at 42.5 to 39.5 million years old) in the Santa Ynez Mountains, above (that is, north of) Santa Barbara, California. All the oysters can be referred to Ostrea idriaensis, which forms persistent--and sometimes spectacular--reefs in the Coldwater Sandstone of Santa Barbara County's Santa Ynez Mountains. Bottom row shows interior views of the pelecypodal oyster valves. Photograph originally snapped with a Minolta 35mm camera. |