Whales in the Sunol Valley?

Since construction began at the Calaveras Dam, team paleontologists have had some remarkable finds from ancient shark teeth to marine mammal vertebrae all collected during the excavation of over 4 million cubic yards of earth over the sediments that were once an ancient sea floor.  

Just this week, project paleontologists found a portion of an ancient whale skull in the slope above the spillway excavation of the new dam. The skull is almost a yard long and relatively intact, except for a small portion of the right rear section which is missing. Our paleontologists are still researching the find but initially assess the fossil to belong to a Mysticete (or baleen) whale, from the family of Humpback, Grey or Blue whales that live in the oceans today and forage on plankton. This fossil was discovered in the temblor sandstone formation which makes it over 20 million years old.

The project takes important steps to salvage these paleontological finds for educational purposes. The critical construction work to build a replacement dam has not been affected and continues, while we discover amazing fossils to add to the rich history of this valley.

Paleontologists Bruce Hanson and Jim Walker work on uncovering fossils at Calaveras Dam. Photo credit: Robin Scheswohl

In November 2013, a collection of bones including vertebra from a marine mammal were discovered on the lower portion of the Spillway.  It appears to show a complete cross section of the body, neural arch and measures 15 x 7 centimeters. Some of the other bones appear to be ribs. None of the specimens found interfered with construction activities and the specimen still remains in the rock.