Even as workers used heavy equipment to scrape away layers of earth at the San Dimas construction site, paleontologist Marilyn Morgan searched the area on foot carrying a small brush, an ice pick and a hammer.
Morgan was looking for the fossilized remains of marine life from an era--scientists say it was about 10 million years ago--when the San Gabriel Valley was part of the Pacific Ocean.
"The things that we pick up will help people in the future understand what happened on this planet in the past," Morgan said.
Fossilized Remains of Whales
Earlier this year at the same site, Morgan discovered fossil remains of a whale, including two six-foot-long jawbones, along with bone fragments from sea lions and birds and several fossilized leaves. Last year, a colleague of Morgan's, Diana Weir, discovered the three-foot skull of a whale at a another construction site a mile away. The fossils from both sites have been shipped to the Los Angeles County Museum of Natural History for study. Museum officials say the discoveries are significant because they are among the very few fossils recovered from the San Gabriel Valley.
"The important thing is, if you don't get to them now you'll never see them," said Lawrence Barnes, curator of the natural history museum. "Once they (the sites) are built on, you don't get another chance."
Barnes and other paleontologists said that hundreds of other fossils could be retrieved from hilly areas in the San Gabriel Valley if more cities and unincorporated areas required on-site paleontological monitoring. He cited Alhambra, Covina, Diamond Bar, La Puente, Pomona, West Covina and Walnut as other areas that might be rich in fossils.
On-Site Paleontologist Required
As it is now, San Dimas is the only city in the area to require on-site monitoring of grading in a fossil-rich area. Under the policy, a developer must agree to retain an on-site paleontologist before plans are approved by the city.
Barnes said the San Gabriel Valley has the same kind of rock with the same potential for producing fossils as Orange and Kern counties, where more than 350,000 fossils have been unearthed in the last 15 years. Both of those counties have designated areas in which paleontological monitoring is required.
The discoveries there led to the recent identification of a new species of prehistoric dolphin, Barnes said.
"We should be seeing a lot more fossils from the San Gabriel Valley, but we don't have people following the tractors at every site," Barnes said. said, most fossils are "being ground up news
and made into fill."
Heinz Lumpp, director of community development for San Dimas, said that city began to require paleontological monitoring of its southwestern hills--known as the Via Verde area--about four years ago.
Lumpp said the decision to monitor such sites came about by accident as a result of a city Planning Commission request for a study of archeological artifacts in the Via Verde area, which Indians are known to have traversed. While conducting its study, the survey team discovered some fossils and reported that others would probably be found in the area.
Via Verde covers about 1,800 acres, Lummp said, and will be fully developed in the next five years. Paleontologists have monitored grading at three housing projects, and two of the three have produced significant fossils.
The first discoveries--a whale skull and other fossils--were made at a 260-acre site being developed for 262 homes by J. M. Peters. The most recent discoveries were unearthed at a 234-acre, 271-home project being graded by Boulevard Enterprises and Anaheim Hills Development Corp.
Grading began last week at a third site, a 140-acre, 189-home development by Standard Pacific Corp., but no fossil discoveries have been made there.
Grading at two sites developed by La Linda Homes and Shuwa Investments Corp. was approved before the paleontology policy was adopted.
City Manager Bob Poff said San Dimas officials are encouraged that fossils have been found in the Via Verde area as a result of the policy.
Lumpp said he thinks it is important to protect such resources despite the extra cost to developers.
Paleontologist Rodney Raschke, a partner with Morgan and Weir in Mission Viejo-based RMW Paleo Associates, declined to say how much his firm has been paid for the work done on the two San Dimas projects.
But the president of another company, Scientific Resource Survey Inc., said her firm charges $100 to $200 a day for such work.
"It depends on the qualifications of the paleontologist and the project," said Nancy Whitney-Desautels.
Constant monitoring is necessary in only a few cases, Raschke said, and some sites require the presence of a paleontologist for only a few hours a week.
Raschke said some developers fear that discovery of fossils might lead to costly construction delays. But, he said, such delays are rare.