Advertisement
YOU ARE HERE: LAT HomeCollectionsDiscoveries

A Big Piece of Prehistoric Puzzle : Well-Preserved Fossil of Whale Offers Clues to County's Prehistory

July 18, 1993|LEN HALL | TIMES STAFF WRITER

LAGUNA NIGUEL — For 24 days in May and June, a team of scientists and technicians were sequestered on a barren hillside here, painstakingly peeling apart the hard-packed soil, sometimes sleeping in tents or under the stars and eating campfire-cooked food.

Their singular mission: Unearth a remarkable 24-foot whale skeleton they named Joaquin and glimpse into the 9-million-year-old Joaquin's world.

When Joaquin lived, most of the land stretching from Santa Monica to Camp Pendleton was under water, paleontologists say. Water lapped up on the sandy shores of the Santa Ana and San Gabriel mountains. Palos Verdes was an island, and early descendants of camels, rhinos and elephants roamed a much warmer, wetter countryside.

Joaquin, now on display at Ralph B. Clark Regional Park in Buena Park, represents another important piece of the vast mosaic of prehistoric life that paleontologists are attempting to construct, said Lawrence G. Barnes, head of vertebrate paleontology at the Natural History Museum of Los Angeles County.

"People always ask why we collect these things," said Barnes, who has made a career of studying the fossils of Southern California. "I answer that fossils are inherently worth saving. As paleontologists, we are reconstructing the history of life on earth."

Joaquin's burial ground lies amid what geologists call the Capistrano Formation, a fossil-rich stretch of rock and silt stone that accumulated over 5 million years, from 4.5 million to 9 million years ago. Thousands of bits of sharks, birds and fish have been found on the one hillside since April, as well as eight sea lion specimens and 13 whales.

But whales, because they are mammals with large, complex brains that lived on land before choosing to move into the sea, add intriguing pieces to life's puzzle that humans can easily relate to, Barnes said.

"They have most of the same bones we have," Barnes said. "They have fingers and toes, kneecaps, elbows and wrists. Early whales had noses at the front of their snouts."

Joaquin represents one of the most complete examples of an ancient whale ever found, one that was covered--and preserved--by layers of silt that accumulated over all those millions of years, said John A. Minch, who with fellow Saddleback College Prof. Thomas A. Leslie, lead the team that found and unearthed Joaquin.

"Joaquin is so complete, it's like an undertaker laid him out there for us," Minch said, adding that his team calls Joaquin a male although they don't know the whale's sex.

Actually, little is known about Joaquin. At first he was thought to be a fin whale, but "he's no more a fin whale than you or I are," Barnes said. "We have no idea what he is. Joaquin definitely belongs to the family they call rorquals, which are baleen whales that live in the open ocean and are filter feeders."

Joaquin was discovered April 1 as part of a study by paleontologists along the entire 17-mile right of way for the San Joaquin Hills Transportation Corridor before final grading begins. Between Alicia Parkway and Interstate 5 alone, a distance of about three miles, paleontologists found 17 significant fossil sites, further testament to the vast fossil deposits in the South County soil.

The ancient animals that died were preserved because they were buried quickly, said Rod Raschke, a paleontologist from Huntington Beach.

"Pretty much wherever you dig in Orange County you find fossils," Raschke said. "The environment is right for the preservation of fossils. With a lot of sediment coming in from the adjacent land mass, the animals would die, get buried in muck and stay buried."

Judging by his skeleton, paleontologists believe Joaquin died a quiet, natural death. Its body cavity probably bloated full of gases after death, and it eventually sank to the bottom on its back and then rolled over partially on its side, just as it was found about 9 million years later, Minch said.

Over time, the land where Joaquin was buried was slowly pushed up by the fault activity in the area. After 9 million years, the uplift from the faults can be dramatic, Minch said.

"People have a problem imagining the uplifting of land," Minch said. "I usually use the example of the Cajon Pass, which is rising 19 inches every 100 years, or 1.6 feet. In 1 million years, that's 16,000 feet."

About 120 feet of sediment covered Joaquin for those millions of years. Several years before the fossil was found, a developer cut into the hillside and exposed the vast array of fossils. At first, the team figured Joaquin was just another of many fossil fragments.

"We were all shocked when we found how extensive Joaquin was," said Leslie, the project manager of the dig. "It's like finding a rock and later on discovering it is a diamond. We knew it was pretty but we didn't know at that time what it was worth."

Advertisement
Los Angeles Times Articles
|
|
|