Before Barney Roamed the Earth : Our intrepid Mesozoic-minded sleuth embarks on a trek back through time (and through three L.A. museums) in search of pre-Spielberg <i> T. rex</i>

With the opening of Steven Spielberg’s “Jurassic Park,” dinosaurs are back. Everything really, really old is new again.

Foreshadowed by the recent popularity of PBS’ kid idol Barney the Dinosaur--and continuing next year with a film version of “The Flintstones”--the fixation with fossils, bones and large predatory reptiles may continue indefinitely, fueled by the biggest marketing campaign in 200 million years. The influence may even seep into the language: “These new alligator boots I got at the Glendale Galleria are, like, totally Jurassic .”

But there is a way to relive prehistory while avoiding the hype.

Hark back, if you will, to Los Angeles in the Age of Reptiles, when dinosaurs ruled not only Hollywood, but the world. A dark and primitive era, 65 million to 245 million years ago, when the plant-eating triceratops and flesh-eating Tyrannosaurus rex shopped Melrose; when the scaly ichthyosaur raised its dolphin-like head from the murky waters of a still-forming ocean and crawled forth for brunch in the Marina; when leather-winged pterodactyls screeched and whirled above the Pasadena Freeway.

And, then, about 1.7 million years ago, came Homo erectus --primitive humans. Echo Park Man. Crenshaw Man. Santa Monica Man. Fairfax Man. Cautious, slow-moving Valley Man, crying out in fear and wonder during Earth’s first rush-hour commute over the hill. All shared a hunger for knowledge, a quest for fire, a tendency to drag their knuckles--and, some archeologists believe, even the same area code.

There are several places in contemporary Los Angeles where you can get a taste of this fantastic time, whether it be the actual Jurassic Period 140 million to 195 million years ago (that’s part of the Mesozoic, or Reptile Age) or newer fossils dating back only 10,000 years.

For the sake of archeological accuracy, we limit our discovery to that period before the 1984 Summer Olympic Games.

GEORGE C. PAGE MUSEUM

Having tar pits in the middle of a major metropolitan area just isn’t normal.

The pools of black glop surrounding the George C. Page Museum in Hancock Park are composed of natural asphalt that seeps to the surface. About 10,000 to 40,000 years ago, those pools spelled doom for unwary animals that were trapped in the goo, where they fell prey to vultures and other predators, which in turn got stuck and died. Because of this, the site represents a treasure-trove of fossils ranging from microscopic one-celled plants to the huge bones of mammoths, saber-toothed tigers and giant ground sloths.

In the early 1900s, the area became a working oil field. Still later, building development and roads caused methane gas produced by oil field residue to be trapped below the surface. Some of this gas escapes harmlessly into the atmosphere and causes the tar pits to bubble slowly. But trapped methane has also caused eerie flames to come up through cracks, seeped into local basements and even caused major explosions, such as a 1985 blast that decimated a Fairfax District clothing store. The city has deemed the area a “high-potential risk zone.”

Denizens of nearby CBS Studios, Farmers Market and the Park Labrea apartment complex seem unperturbed by this--anathema to people who have relocated from Detroit, which is not exactly Paris, but at least there one never hears the phrase “Honey, the sidewalk is on fire.”

But you can’t live forever, and in the meantime, you might as well take a trip to the Page Museum and La Brea Tar Pits to “Discover What It’s Like to Be Trapped in Tar.” A museum exhibit provides metal plungers that you can dip into a vat of thick asphalt and test the resistance as you try to pull it out.

Museum exhibits include reconstructed skeletons of Ice Age mammals, including primitive horses and deer, tigers, camels, mammoths, bears, birds, sloths and dire wolves. The only human bones discovered in the tar pits belong to La Brea Woman, who died 9,000 years ago at the age of about 25. The museum also features the so-called fishbowl museum, where visitors may observe staffers sifting through tar pit matter for fossils.

Then, one moves on to a Tar Pit Tour, whose challenge consists of trying to figure out why Pit No. 10 doesn’t look any different from Pits Nos. 5 and 4. These might more aptly be termed La Brea Tar Puddles. The monotony of the visuals is somewhat eased by cheery narration from a tour guide. On a recent tour, our guide, Howard, expounded on the unique characteristics of each pit (one provided a wealth of sloth parts, another was filled with early elephant bones), told bad jokes and provided folksy information about local plant life as well as the area’s former residents, the Gabrieleno Indians.

A highlight of the tour is the Observation Pit (No. 91). A glassed-in booth allows visitors to look down into the shiny black pit, the only one still being excavated for fossils. From June 30 to Aug. 29 volunteers will toil under hot sun, scratching through oozing tar at a glacial pace, hunting for clues to ancient life. Major discoveries are rare; according to Howard, these patient, dirty diggers mainly uncover “snake teeth, mouse toes, insect parts.” For some, he said, the thrill of finding a mouse toe that hasn’t seen the light of day for 25,000 years makes the grind worthwhile.

* George C. Page Museum of La Brea Discoveries and La Brea Tar Pits, southeast corner, Hancock Park, 5801 Wilshire Blvd., (213) 936-2230. Open Tuesday-Sunday, 10 a.m.-5 p.m.; closed Monday (except June 28). Admission: adults, $5; students and senior citizens, $3.50; children 5-12, $2; free on the second Tuesday of each month.

NATURAL HISTORY MUSEUM

This museum in Exposition Park may be the only spot in Los Angeles where you can truly get Jurassic.

While the tar pits take you back a mere 40,000 years, this museum goes back to the age of the dinosaurs. Our Jurassic friends include the 120-million- to 180-million-year-old ichthyosaur and the 60-foot-long adult camarasaurus, whose skeleton is displayed in the child-friendly, hands-on Ralph M. Parsons Discovery Center.

Nerd fact: The tyrannosaur, bad guy of “Jurassic Park,” actually isn’t Jurassic at all. Instead, according to museum plaques, Tyrannosaurus rex is about 70 million years old, which places the creature near the end of the Cretaceous Period, not the earlier Jurassic Period.

On a recent Wednesday, there were more dinosaurs and early mammals than people in this nearly deserted museum. Like the Page Museum, the Museum of Natural History is owned by Los Angeles County and relies heavily on tar pit finds. Hardly high-tech, this dimly lit facility is comfortingly reminiscent of grade school field trips. In the African mammals section, huge glass cases enclose three-dimensional scenes featuring stiff, balding prehistoric animal replicas interacting with their environment.

Later this summer, the museum will temporarily dismantle the camptosaurus and allosaurus skeletons in the main foyer to make room for a temporary folk art exhibit, but there remain many great dinosaur bone structures throughout the museum. The museum is taking donations for a permanent dinosaur hall called “Journey Through Time.”

And, if you are not too distracted by the Natural History Museum’s fine exhibits on California history and global warming, and its dazzling display of rocks and minerals, try following the “trail of ants” to the Insect Zoo, which displays live descendants of prehistoric insects. As evidence that evolution may not have had the best plan, note that the oldest living creature is thought to be the cockroach, descended from insect groups that lived more than 400 million years ago.

* Natural History Museum of Los Angeles County, 900 Exposition Blvd., (213) 744-3466. Open Tuesday-Sunday, 10 a.m.-5 p.m.; closed Mondays (except June 28). Admission: adults, $5; students and senior citizens, $3; children 5-11, $2.

JURASSIC TECHNOLOGY

Jurassic fiction or Jurassic fact? It’s all a matter of perspective. David Wilson, director of the Museum of Jurassic Technology, has invented his own perspective on science.

After touring some traditional halls of prehistory, a journey to the tiny museum on Venice Boulevard near Motor Avenue offers a refreshing antidote to the academic approach, an alternative to the conventions of higher learning, a 90% successful cure for a terminal case of Ph.D.

The dark, almost funereal museum is run by Wilson, 47, a former movie miniaturist who now devotes himself full time to the museum’s stated mission: “The advancement of knowledge and the public appreciation of the Lower Jurassic.” The learner must “be led always from familiar objects toward the unfamiliar . . . guided along, as it were, a chain of flowers into the mysteries of life.”

According to a map provided by the museum, the Lower Jurassic is just above the Upper Jurassic and just south of the Mediterranean Sea. (For Wilson, converting time to place is not a problem.) The museum provides a “hands-on experience of life in the Jurassic.”

Wilson, a tweedy, horn-rimmed sort who calls this pursuit an “obsession,” waxes rhapsodic as he explains his off-kilter museum. One who goes to the Museum of Jurassic Technology expecting dinosaurs is instead confronted with Wilson’s own peculiar definition of reality, preserved here for all time.

“The name came first, and over time we have come to kind of understand what the name, in a way, has meant,” he says earnestly. “We are interested in the technology behind nature, or natural technology, since there was not technology, in the traditional understanding of the word, in the Jurassic. It implies, in a way, that there is a technology behind nature.

“It is probably not true and not wise to look at human beings and their endeavors as separate from the reason of nature.”

Wanting always to be true and wise, it is best not to question Wilson’s theories, or his map of the Jurassic, but to simply experience the museum. It is filled with exhibits illuminating many arcane subjects, as well as providing more information than you ever wanted about concepts that traditional science has laughed at, rejected or simply refused to be bothered with.

The multimedia museum includes a display on the extinct ringnot sloth; an exploration of “Life in the Extreme Ultraviolet,” in which the healing power of rays is shown in a “plasmotic post-visualization” demonstration that miraculously replaces the skin on a skeleton of the hand, and the deprong mori, or piercing devil, a bat that possesses the extraordinary ability to fly through solid matter.

Then there is the fascinating Horn of Mary Davis of Saughall, a replica of an actual horn made of coarse hair that was thought to have once grown, circa 1688, on the back of Mary’s head. “That horn is, in theory, in the British Museum,” Wilson says. “They say they’ve lost it.”

Also explored are the interconnecting lives of Madalena Delani, a classical singer with Korsakoff syndrome (a disease that destroys the short-term memory), and Geoffrey Sonnabend, a memory researcher who hypothesized an intricate theory of forgetting. This exhibit, as well as others, allows visitors to access lengthy narrations through the use of telephone receivers; these are both informative and intensely dull.

Wilson acknowledges that his museum is not for everyone. Some visitors laugh hysterically. Others tour the facility in silent appreciation. Still others, Wilson says, get angry at this assault on conventional science. He adds that some people, tragically born with no sense of humor, believe the museum to be part of some satanic cult.

Wilson enhances the Jurassic experience by playing impromptu accordion concerts on the sidewalk outside while one tours the museum. Along with the museum’s own sound effects--which include dog-yelping, a bubbling waterfall and occasional bursts of sweet music from Madalena Delani Hall--the effect blends the mystery of an Argentine rain forest with the festive aura of a French cafe.

* Museum of Jurassic Technology, 9341 Venice Blvd., (310) 836-6131. Open weekends, noon-6 p.m.; Thursday, 5-9 p.m.; expanded hours begin July 1. Suggested donation: adults, $3; students and senior citizens, $2.