"Oh, Lordy, Lordy! These are teeth connected to a jawbone," said Ed Cole Jr.
Leaning in as if he and Cole were peers, our son Josh, 12, brushed aside crumbled sandstone and said: "Look! There's more bone."
Cole uncovered another attached tooth. His voice rose: "My heart's going a hundred miles a minute. This is the first time we've found teeth connected to jawbone in this whole ridge."
We were outside Thermopolis, Wyo., at Warm Springs Ranch, where dinosaur bones were discovered in 1993. Since then more than 1,500 bones -- including two nearly complete Camarasaur skeletons -- have been removed.
More than 50 dig sites have been identified in this square mile of gray-green mudstone and buff sandstone. Because experts estimate it may take 150 years to find all the bones, amateurs are welcome to work alongside professionals in pay-to-dig programs.
Our family of four signed up for a day dig one hot August day. We began with a half-hour orientation at Wyoming Dinosaur Center, a privately owned museum built in 1995. Next to the lab, where visitors watch technicians prepare and mount bones, we saw a 9-foot-long Camarasaur leg bone from the dig site.
"Do you think we'll find anything?" asked our son Abram, 14.
The shuttle bus jounced two miles through scrubby hills and up a gouged-out ridge, where bulldozers had peeled away sagebrush and juniper to expose bone beds formed by an ancient stream channel. One geologist was jackhammering a stubborn piece of rock. A couple others were mapping and measuring huge exposed bones.
As we followed Cole a quarter-mile downhill to our dig site, I could feel dust caking my skin, pebbles working into my sandals. A blue tarp shaded lawn chairs and coolers from intense sun. I wondered how anyone could find anything but more rocks in this barren spot.
Cole pointed to a large bone in a cardboard box. "That's the biggest we've found in this site so far this summer -- probably a vertebra from a meat eater. A day digger found it yesterday," he said.
He handed us each a rock hammer, pick, small shovel and paint brush, then showed how to loosen and split rock chunks, examine them and brush debris downhill.
"It takes half a day to get an eye for soil, to see differences in colors and shapes. But 99 percent of people find at least a bone fragment," he said. My husband, Steve, a former science teacher, unearthed two fragments right away.
Forty minutes later, Cole said, "Here's a chevron from a Diplodocus -- and here's a rib." While we chipped along the rib, he explained that a chevron hung below each tailbone in a plant-eating dinosaur. Most chevrons were Y-shaped, but many Diplodocus chevrons were V-shaped, like the one we were staring at.
When the rib's whole front edge was exposed, our family was amazed. The reddish fossilized rib was four feet long. Cole remained blase. The rib seemed big to us, but in 1994 he had uncovered a 450-pound sacrum (a bone attaching backbone and pelvis) on-site.
His father, Ed Cole Jr., is the fossil prospector who discovered dinosaurs at Warm Springs Ranch. His mother, Ava Cole, found a previously unknown horned dinosaur in Montana in 1981; it was officially named Avaceratops in her honor. A dozen of the trilobytes (ancient marine insects) that Cole and his father found elsewhere are in the Smithsonian.
We lunched uphill under a canvas lean-to, listening to the geologists -- all under age 30 -- debate paleontological theories as easily as most people discuss sports or the weather. "This is a very inexact science, with lots of room for speculation," geologist Cheryl Bjoraker told us.
Every hour the shuttle bus crawled up the ridge, bringing another load of dig tour visitors. We joined a group to learn about the upper dig sites.
"This rock layer is about 150 million years old. It's from the Jurassic period, when dinosaurs ruled. So far we've identified seven dinosaur genera," said geologist Sean Fishbaugh. He passed around a spoon-shaped Camarasaur tooth, then held up a claw and a bone gouged by a predator's teeth.
Pointing to three-toed footprints that appeared to have been made by a 100-ton chicken, Fishbaugh said, "We think these were made by an Allosaur, a large carnivore. Finding Jurassic footprints and bones in the same site -- as we have -- is rare. Evidence here may show that parent Allosaurs brought food to their young."
Looking at plaster casts encasing Stegosaur bones renewed our desire to discover something notable. We trekked downhill again to move more rock -- lots of it. The sun was even hotter. No matter how much ice water and Mountain Dew we guzzled, we felt parched. Steve retreated under the tarp, but Abe and Josh weren't ready to leave.
"Dusting rock is very peaceful," Abe explained. I asked Cole whether he ever gets bored, chipping at rocks day after day. "Are you kidding?" he replied. "I'm sitting where the largest animals that ever walked this earth once were. These bones sat here 150 million years, and now I'm touching them.
"But I'm interested in all elements of this landscape. I've seen elk and golden eagles on this ridge. I love the intricate details of prehistoric ferns and clam shells," he said.
Abe hit a rock chunk and out flew several bone parts. Josh found one fragment, which Cole reattached with Superglue. We could see the negative space where the bone had been preserved in rock.
The boys hadn't kept their ledge swept as clear as possible, so fragments were hard to spot. But Cole sifted debris and spotted the missing pieces. "Basically, what it takes is a willingness to walk and an interest in how rocks are formed. Then you can find anything," he said.
Josh re-examined a bumpy rock. "Hey, is this anything?"
"Wow, that's interesting. This pebbled surface could be fossilized baby dinosaur skin. If it is, it would be the first we've found on this ridge," Cole said.
That's when he uncovered the jawbone. "We've found dozens of teeth, but never any still attached to bone. We've got a chance to find a whole skull here," Cole said, working eagerly but gently to reveal more of the fossil.
The last shuttle bus arrived before he and Josh figured out how much jawbone was buried. Our day dig was over. Cole needed to confer with the other geologists about the day's discoveries. We parted, promising to keep in touch by e-mail.
When the bus dropped us off at the Wyoming Dinosaur Center, we wondered whether our finds would ever be displayed. The 16,000-square-foot center uses hundreds of fossils and a dozen dinosaur skeletons (most are realistic casts) to show the evolution from early Precambrian life forms through the Cretaceous Era, when dinosaurs died out.
Several months later we learned by e-mail that the chevron and rib were indeed from a Diplodocus. Cole had just finished preparing the jawbone fragment, apparently from a Diplodocus upper jaw. Though only parts of a skull had been been found, Cole said they were unusually well preserved, with "exquisite detail and definition" between bone junctures.
The e-mail concluded, "Sorry, Josh, the fossilized baby dino skin turned out to be gypsum crystals."
Josh didn't mind. "Digging there was so much better than looking for fake bones in a sandbox at a museum. They actually let us discover things," he said.
There are several places in the United States and Canada where you can dig for dinosaurs or tour dig sites. All digs require advance reservation, though you can sometimes get last-minute spots for day digs. Digs anywhere depend on weather.
Wyoming Dinosaur Center and dig sites, Box 868, Thermopolis, Wyo. 82443; (800) 455-3466.
Day digs are offered daily from late spring through early fall; includes all materials, lunch, drinks and transportation between WDC and dig site. $100 per person; $250 for a family of up to two adults and two children; $50 per extra child. Discounts for multiple days. Those under 18 must be accompanied by an adult.
From January to April, the museum is open daily from 10 a.m. to 5 p.m.; dig sites are open daily, 11 a.m. to 4 p.m. as weather permits. From May to October, the museum is open daily, 8 a.m. to 8 p.m.; dig sites are open from 9 a.m. to 5 p.m. (last tour bus to site at 4 p.m.).
Museum of the Rockies Paleontology Field Program, Montana State University, 600 W. Kagy Blvd., Bozeman, Mont. 59717-2730; (406) 994-6618; http://www.montana.edu/www.mor/. Dig site is near Choteau, west of Great Falls, Mont. In 1978, Dr. Jack Horner found a nest of baby hadrosaurs here. It was the world's first evidence that dinosaurs cared for their young. Overnight digs include meals and lodging in Blackfeet tipis.
Day Digs: June 22 and June 23, includes lunch. $95 for ages 15 and up; $75 for ages 10 to 15, must be with an adult.
Introductory Field Paleontology: June 27 to July 3, July 11 to 17, July 25 to 31; $1,100; ages 15 and up only.
Advanced Field Paleontology: Aug. 9 to 18; $1,450; ages 15 and up only.
Free dig site tours are offered daily at 2 p.m. from late June to late August.
Dinosaur Expeditions, Museum of Western Colorado, P.O. Box 20,000, Grand Junction, Colo. 81502-5020; (970) 242-0971; http://www.mwc.mus.co.us. Museum paleontologists and educational staff lead expeditions to quarries in western Colorado and eastern Utah. Digs include meals, transportation between museum and dig site, plus tent lodging for overnight expeditions. Children under 16 must be accompanied by an adult.
Day digs are offered most Thursdays and almost any day that four or more diggers sign up; $75 per person ($60 per person for 10 or more people). Two-day digs are offered by special arrangement only; $175 per person.
Six-day digs for serious paleophiles are available May 4 to 9, Aug. 24 to 29 and Sept.7 to 12; $699 per person.
Royal Tyrrell Museum of Paleontology, Bookings Office, Box 7500, Drumheller, Alberta, Canada T0J 0Y0; (888) 440-4240 or (403) 823-7707; http://tyrrell.magtech.ab.ca. North America's largest paleontological museum lets amateurs work side-by-side with museum staff in southern Alberta Badlands. Finds have included T. rex, Albertosaurus and Pachyrhinosaurus, the last horned dinosaur of its type.
Day digs are offered weekends from June 6 to 21, daily from June 27 to Aug. 30; includes lunch, transportation and museum admission. $85 for ages 16 and up; $55 for ages 10 to 15 accompanied by adult; 30 percent discount for second and subsequent days. All prices in Canadian dollars.
Two-hour dig site tours from June 27 to Aug. 30 leave daily at 10 a.m., noon and 2 p.m.. $12 for ages 18 and up; $8 for ages 7 to 17; free for ages 6 and under; $30 per family (two adults and their children ages 17 and under).
One- and two-week field experience: June 7 to Aug. 30, Sunday to Saturday, for ages 18 and up only. Rugged work; includes rustic lodging in trailers, all meals, work-related supplies. Priority given to two-week participants. $800 for one week; $1,500 for two weeks; $600 for third and subsequent weeks. Non-refundable $300 deposit holds reservation.