Now that I’ve been back from hunting dinosaurs with Project Exploration for a few days, I owe you all the report. I’m not going to go into all of the background, as that was covered pretty well in my blog posts about the 2004 trip, Dinosaur Report I and Dinosaur Report II. So this will just be a little photo-essay about the heavy lifting that was specific to this trip.
During the previous two trips I had been on with Project Exploration, the focus was on prospecting and the early stages of bringing fossils out of the ground. Clearing away the dirt, exposing bone, determining what we found, estimating the physical extent of the fossils. The eventual goal, of course, is to clear away everything but the bones and enough rock (called “matrix” in paleo-speak) to hold it together, wrap up the pieces snugly in wood and plaster (“jacketing”), and bring it all back home — in this case, Paul Sereno’s lab at the University of Chicago. But the process as a whole takes time, and three days of work by a crew of enthusiastic but untutored amateurs generally isn’t going to make it happen. But on this trip we were working on a site where most of the work had been done, and our task was to finish the job. In fact, we were back to the site I had gone to in 2005. In the meantime the locations of the various bones had been ascertained, many of them had been fully jacketed, and our task was primarily to finish off the biggest pieces. “Finishing off” means completing the jacketing process and transporting the jackets to Billings, Montana, where a freight company would carry them to Chicago.
The story is conveyed better by words than by pictures. Click to get hi-res versions in a new window.
Here is a view of our vans, as seen from the dig site. Each morning we’d get up bright and early to have breakfast at Dirty Annie’s (the finest dining establishment in all of Shell, Wyoming, featuring chokecherry pancakes the size of garbage-can lids). Afterwards we’d head out to the site in two rented vans, the backs of which were filled with all the paleontological necessities: burlap, plaster, water, picks, awls, hammers, GPS units, shovels, trowels, gloves, 2×4’s, buckets, tarps, brushes, kneepads, and sundry snack foods. The vans would bounce over dirt trails to the foot of the hill where the fossils were, and we would all jump out, eager to get our hands dirty. (On at least one occasion, unanticipated logistics forced the crew into drafting a theoretical physicist into van-driving duty. Thankfully, nobody was seriously injured.)
And here is the dig site, as seen from where we parked the vans. Just to the left of center there you can see the plaster around the main group of fossils — jacketing that bad boy and trucking it to Billings was our primary challenge for this trip.
For some reason (too excited by the goings-on, probably) I neglected to take a close-up photo of the main fossil group before we covered it with plaster. But to get the idea, here is a smaller group, this one a collection of vertebrae. In the field, the main goal is to roughly carve out the bone and get it back to the lab in workable condition. On the other hand, you don’t want to make it heavier than it needs to be, so you try to remove as much matrix as you can without sacrificing the structural integrity of the fossil. Once the bone is exposed, you cover it with tinfoil, then wrap it with burlap strips dipped in plaster. Delicate soul that I am, I resisted participating in the plastering at first, but ultimately I realized that everyone else was right, it really was the most fun part of the whole procedure. To make the jacket a bit stronger you can plaster pieces of wood to the whole collection, as seen in the bottom part of the picture.
Here is Paul on the first day, explaining to our intrepid crew of newcomers what we’ll be doing out here. The part of the process for which I was best suited was the delicate work with an awl and a brush, clearing away bits of matrix right up against the bone. Probably I’d be even better suited for the close-up work performed by the preparators back in the lab, who work under microscopes to remove things at the grain-of-sand level and reconstruct the bones. Actually, come to think of it, I’d be best suited to be sequestered in a room far away from any fossils, left with a pen and paper to think about the universe. So that all worked out for the best.
Paul, eager to get going, burns off nervous energy by doing push-ups. (He was the only one to employ that strategy.)
Here is the main collection of fossils, separated out from the surroundings and covered on the top with plaster. It consisted of vertebrae, ribs, and sundry other bones that I won’t pretend I could identify. Paul figured that it was a sort of Diplodocus, one of those lumbering herbivores with giant necks and tails that roamed North America during the Jurassic. But the structure of the hip bones differed from that of the ordinary Diplodocus, so Paul judged that it was a new species. By the second day he had promoted it to a new genus — apparently the rules for whether a new species is in a distinct genus or an entirely new one are a little fuzzy. In any event, our job was to hack away at the underpinnings of this rock, and eventually to bring it home.
And away we go!
Here’s what it looks like after a bit of progress. You can see that the supporting rock beneath is being stripped away. The lip is supported temporarily by piles of stones; as soon as is feasible, we wrap plaster-soaked strips of burlap around the matrix to keep it from crumbling.
Once most of the rock is cleared away from beneath the bones, and some 2×4’s plastered to the top to give it some structural integrity, we bring in a miniature excavating shovel to help flip the thing on its back. This was one of the only times during the dig that we used machinery of any sort. Paleontology is culturally at the opposite end of the scientific spectrum from particle physics or astrophysics — even the most cutting-edge work relies much more on elbow grease and sweat than elaborate equipment.
After a bit of impromptu mechanical engineering, it is decided that the strategy will be to tie the jacket to the shovel with chains, and then lift up the shovel. The majority of the team, rendered temporarily superfluous, stands in the background taking pictures. I decided to take pictures from the other side — that way I would appear in everybody’s pictures.
Wrapping chains securely around the jacket.
The moment of truth — the shovel lifts, tearing the fossils away from their remaining connection to the ground below.
Tipping the jacket over onto its back. Our best guess was that the thing weighed a bit over one ton (about a thousand kilograms, for you foreigners). You wouldn’t want to catch your toes underneath it.
And there we go! The beast is on its back. Except — it didn’t go quite as planned. In the process of flipping, the jacket suffered a fracture through the middle. You can see evidence of the damage at the bottom left of the picture, where one of the wooden supports has broken. As it turns out, the plaster we had been using on the first day had become brittle and useless by the second day, for reasons which weren’t clear. It wasn’t any fault in the yeomanlike effort of our plastering crew; more likely, some quality of the water or plaster made for an inferior product. (A problem that we were able to fix in subsequent sessions.)
But, as they say in New Orleans, shit happens. If there is any single lesson one learns from being out in the field, even under such relatively tame conditions as our trips to Wyoming, it’s that success doesn’t come from following the dictates of some imaginary instruction manual. It’s about phronesis, in a very down-to-earth sense — the practical wisdom that comes from a combination of innate understanding and countless hours of experience. You make do, as best you can, with what circumstance presents to you. And the rest, you hope the preparators take as a challenge.
So we got back to work, and jacketed up the (new) topside of that puppy! Using hardy new plaster. And here is the result of our efforts, a conglomeration of bone, matrix, wood, burlap, plaster, and fabric straps, tagged with gold spraypaint for easy identification back home. (Paul has over 25 tons of specimens from various expeditions sitting a warehouse near O’Hare, which the lab is gradually working its way through.)
And the gang pauses for a commemorative photo at the scene of our triumph.
Except the story is by no means over. We need to flip the thing again, to re-plaster the crumbling side, and then carry the whole shebang into the waiting U-Haul truck for transport back to Montana. Having that little excavator lift and carry the one-ton jacket was the cause of no small amount of anxiety — you can see that the specimen was listing rather alarmingly to starboard. But what can you do? You can also see Paul, laying on his back, snapping a picture of the shovel lifting the jacket. The pros are just as excited about this stuff as the rest of us are.
And the excavator swings around to deposit our hundred-million-year-old fossil in the bed of a rented truck that was last used to move some bean-bag chairs from Des Moines to Billings. (I don’t know that for sure, but it seems likely.)
And a tight fit that was, too. We got the fossils in there, although some of the excavator’s green paint was scraped off onto the door of the truck. I don’t have a picture of the jacket getting all the way in there, because at this point I (correctly) judged that I could be more useful helping to push the thing the last couple of feet onto the truck bed, rather than snapping photos.
By now, the bones have probably been deposited somewhere in Chicagoland. And at some point down the road, a paper will be written announcing a new species of Diplodocus. Or a new genus, whatever. And some enthusiastic amateurs from a variety of ages and backgrounds got an up-close look at science as it is done for real.