‘We literally lick rocks’: Utah paleontologists describe process of excavating fossils

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Paleontologist Randall Irmis, the curator of paleontology at the Natural History Museum of Utah, extricates a fossilized rib from the matrix containing the fossilized remains of a tyrannosaur found in Grand Staircase-Escalante National Monument Tuesday, Oct. 3, 2017. The skeleton was the most complete of its kind found in the Southwest United States. Mark Johnston/NHMU

UTAH (ABC4) – Paleontology can be a challenging and taxing field, both mentally and physically. Those who devote their lives to studying ancient life not only combine a scientific approach to learning more about extinct plants and animals but also must venture into the field to extract specimens for further study.

One of the most crucial aspects of excavating a fossil can be distinguishing bone from rock. While there are some highly advanced processes in fossil recovery, one of the paleontologists’ most effective tools can often leave a funny taste in their mouth.

“We literally do lick rocks sometimes,” Randy Irmis, one of the top paleontologists at the University of Utah, tells ABC4.

Irmis explains that due to bone’s more porous nature compared to rocks, the moisture from a tongue will stick better to it and reveal which parts of a potential discovery are bone and which are rock.

“Nothing’s infallible. There are always exceptions to the rule, but it’s a pretty good test usually,” Irmis states.

Apart from sometimes having to place their tongues on million-plus-year-old rocks, the scientists who locate and excavate a fossil — which can range from a small leaf impression to an entire dinosaur specimen — do grueling and tedious work.

Having mapped the entire state, thanks to work by the Utah Geological Survey, paleontologists can choose an area known to have a history of rocks and fossils that date back in the tens of millions of years. Once they head out to look for specimens, they make their way into the area packed to the gills with all kinds of equipment, such as digging tools, glue, plaster mix, water, and toilet paper (more on the toilet paper in a bit, it’s not for what you’re thinking).

From there, it gets to be less about science and more about hunting.

“You’re looking on the ground and you’re dropping on your hands and knees and crawling and sniffing pebbles to try to find a little bit of bone that are coming out on the surface,” Jim Kirkland, Utah Geological Survey’s state paleontologist, explains.

Little things, such as texture, lighting, and even what appear to be stains on the rocks, can be clues that something valuable is resting under the surface. If paydirt, AKA a bone, is found on an initial dig, the real work begins.

In a process that can feel like it rivals the length of time the dinosaurs have been extinct, the diggers begin to carefully delve their way around and a bit under the specimen, creating what can look like a platform or mushroom effect with the fossil propped on top of the dug-out area.

It’s important to go carefully and deliberately, both paleontologists tell ABC4.com, as the bone can be extremely fragile. Should it start crumbling apart, glue is applied to keep the structure at least somewhat intact until the whole thing can be moved to the laboratory for a more detailed extraction.

Getting the specimen to the lab can be the most difficult part of all, especially on a bigger discovery.

Once the paleontologists have a good feel for what they have uncovered, they begin wrapping the fossil in plaster to protect it during the transportation process. To provide a “buffer” or “separator” between the bone and the plaster, the toilet paper, which has been hauled into the dig site, is applied first. Then, once the bone is completely encased in what is essentially a giant cast, it’s ready to be taken back to a laboratory. However, depending on where it was found, it’s not as easy as bringing in machinery and a flatbed truck to haul it out, although that is a preferred method.

Sometimes, scientists are forced to resort to more primitive means.

“A brachiosaurus, like the one the folks at the Vernal Fieldhouse collected last year by Capitol Reef, that thing by itself, a limb bone, weighed 1,000 to 1,500 pounds. They used a mule team to get that thing out of the desert,” Kirkland recalls. “They don’t like us driving around back there.”

Whether by helicopter lift or by the strength of a team of mules, the fossils finally make it back to the research lab where the process becomes even more granular. Working with a smorgasbord of tools — ranging from a medical-grade cast cutter to remove the plaster, to a tiny jackhammer and air compressor used under a microscope — the arduous task of revealing the slowly ancient life takes shape.

And by slowly, paleontologists mean EXTREMELY slowly.

“In certain things like the Utahraptor block, exposing a square centimeter a day is actually moving pretty fast,” Kirkland explains, adding that the work of fully exposing a large, recently recovered specimen of a Utahraptor in his lab could take decades to accomplish.

For the people who choose to do the fascinating and painstaking work of paleontology, Kirkland says there’s no better place than Utah to do so.

“We’ve discovered like 100 new dinosaurs in the last 25 years,” he states. “We are literally the hottest place in the world for discovering.”

Kirkland, a highly regarded voice in the paleontology realm, jokes he’s “getting too old” for the back-breaking work of excavation. Irmis, however, a few years his junior, gets his biggest thrill out of the labor of bringing hundred-million-year-old bones back to the surface.

“I really love fieldwork and digs and so, you know, each one is unique in its own way and it’s really hard to pick,” Irmis says when asked about his all-time favorite dig. “It is tough. But I really enjoy it.”

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