The Bones exhibit at Santa Cruz Natural History Museum is here just in time for Halloween and will run until Feb. 26. The exhibit recalls a time when every day was like Halloween in Santa Cruz, when strange beasts roamed our shores and mountains.

During the last ice age, which ended some 11,000-12,000 years ago, central California, and even Santa Cruz, had mammoths and mastodons—elephant-size plant eaters—saber-tooth cats, giant ground sloths about size of bears, camels and rhinoceroses, as well as walruses and sea cows—a skeleton of which hangs form the museum ceiling.

"If you looked around Pajaro Valley, say 220,000 years ago, it would be like going on a safari in East Africa," says Frank Perry, who designed the exhibit.

Nobody knows where these animals went, although in recent years, the idea has gained ground that paleo-Native Americans who settled here hunted the big game to extinction. Other theories are that disease or climate shifts wiped them out. Whatever the case they are gone—but not so their bones.

On display at the museum is a giant mammoth skull and a molar found in 1973 in Watsonville that is 50,000-100,000 years old. There's an ancient whale skull, which visitors can touch if they don't mind getting a little dust from the brain case on their fingers. There are also more contemporary animal remains, like a shark vertebrate, bird skeletons, mollusk shells, skulls from mules, deer, horses, pigs and pronghorns. There's cattle bones found up at UC Santa Cruz, which reveal the diet of lime workers who lived there in the 1800s. A 6-foot whale rib stands next to a Trowbridge's shrew vertebrate, which is so small you can barely see it.

The exhibit was sponsored by various local businesses, like Cruz Car Wash and Cafe Pergolesi's, and was designed by Frank Perry, an earth scientist who attended UC Santa Cruz. Perry does exhibits for museums and park visitor centers on a freelance basis and has worked as a paleontologist on digs for UC Berkeley and the Natural History Museum at Los Angeles County.

Usually, these bones are stored away in drawers and never viewable by the public, Perry says. Most came from loans by Santa Cruz's history museum, UCSC and Rancho Del Oso Nature and History Center.

A number of the bones were also donated by locals who, over the years, unearthed them, often by accident. For example, a local high school student looking for old bottles made it into The New York Times in 1980 for finding a mastodon skull in Aptos Creek. The skull is between 20,000 and 100,000 years old and is viewable at the Bones exhibit.

The fossil was a rare find, as no mastodon bones have been found in these parts since. But if the area was once so heavily populated by these and other ancient animals, why haven't more bones turned up?

Part of the reason for the bone scarcity, says Perry, is that rules about where people can look for bones have gotten a lot tighter, limiting where hobbyists, university students, and professionals can look.

"Santa Cruz County in particular has gotten so built up and has so many rules and regulations," he says. "There are fewer and fewer places you can look, because it's all private and restricted." 

Perry says it's a new world for bone hunters.

"It's part of an overall trend, which is kind of a shame, because when I was growing up, my parents would take me up to some of the quarries in Scotts Valley and spend the day digging for shark teeth. That's what's got me interested in all this stuff, and it would be nice for young people to be able to do this."

State parks can't be disturbed without special government permits, and private land is off limits to all but the owners, who often worry about liabilities if they permit excavations. As a result, many bones turn up as a result of construction projects that unearth them.

Still, if one wants to look, a fossil may turn up. The first rule, Perry says, is to look in sedimentary rock. A good place to hunt is near creek beds or lake shores, where bones are more likely to have been rapidly buried. Perry hopes to see more discoveries in the coming years, as the uncovering of such old bones is the key to our map of evolution and the past.

In the meantime, a good section of that puzzle is already on display above ground at the Bones exhibit.

Perry and other experts will speak about bones at the Santa Cruz Natural History Museum on Saturday mornings in February 2011. Contact Kristen Van Cley at 831-420-1135 for details.