San Diego Natural History Museum--Your Nature Connection[BRCC San Diego Natural History Museum: Paleontology]
Paleo Finds Dig Up the Past

October 2001

Staff from the Museum's Paleontology Department have made several significant fossil finds in San Diego county—two baleen whale skeletons and a partial skeleton of a Columbian mammoth.

Of the two baleen whale skeletons found, one is nearly complete and consists of a skull measuring 6.5 feet in length with articulated lower jaws, spinal column, ribs, and partial flippers. This fossil whale is estimated to have been about 32 feet long. Hit and uncovered by a bulldozer, it is unusual to find so complete a fossil intact. Both skeletons belong to a fossil species that is new to science. The specimens were discovered in ancient marine sandstones deposited during the Pliocene Epoch, approximately 3.5 million years ago. The discovery sites are at Otay Ranch, an Otay Ranch Company development in eastern Chula Vista.

The fossil whales were recovered with cooperation from the grading company (W.R. Connelly) and salvage support from the Otay Ranch Company without affecting the construction schedule or causing any damage to the whale remains. With a lot of work ahead of them, the Museum's paleontologists expect the fossil preparation to take a long time

In early October, 2001 Brad Riney discovered remains of a Columbian mammoth in Oceanside in the San Luis Rey River Valley on the site of the future Lowe's Home Improvement Center in the Old Grove Marketplace development, under construction by Seabreeze Development.

Also unearthed by a bulldozer, the mammoth fossils were found in an ancient soil deposit that formed between 100,000 to 300,000 years ago in the floodplain of the ancestral San Luis Rey River. The condition of the mammoth fossil remains suggests that the skeleton was exposed at the surface for a long time before it was finally buried and preserved.

Found were a complete tusk measuring about 7 feet in length, numerous molar teeth from the upper and lower jaws, portions of several ribs, and partial limb bones.

This specimen represents the most complete fossil mammoth found in the coastal area of San Diego County. Museum paleontologists will be cleaning and repairing the mammoth remains, some of which will be put on display in the near future.

photo of  uncovering of mammoth
Brad Riney excavating a partial mammoth skeleton at Old Grove Market Place in Oceanside. The large plaster jacket to the right of Brad contains one of the fossil tusks.

photo of uncovering of whale skeleton
Pat Sena unearthing a baleen whale skeleton at Otay Ranch in Chula Vista. The large flat bone in the foreground is the right scapula, which was found articulated wih the rib cage and spinal column of this 3.5 million year old fossil.

photo of uncovering of whale skeleton
Richard Cerutti digging up a fossil baleen whale skull discovered at Otay Ranch, Chula Vista. The small white card on the skull marks the position of the "blowholes." Note the articulated right and left lower jars in the foreground.

Text and photographs by Dr. Tom Deméré