Hunting Fossils - Part 3

By the end of the day, I’m whipped. Sweating, dusty, gritty, I take my haul back to the office. I have plastic bags marked with slips of paper as N14V-1, N14V-2, and so on. These markings are unique in this year, and they correspond to entries Marcie has made in the log book. The codes connect to her written description and to photos taken of the site. Or, in my case, a single photo, as the hillock I worked on yielded nothing spectacular.

Today, nothing spectacular was found by any of us. For the whole month, the best find was a single entelodont tooth in perfect condition, probably an m1, or lower molar. The woman in the group with the smallest hand could not close her hand around it--it’s that big. Had we found a canine--the fang--it would have been longer than the largest hand of the group. And we looked for it. (image-google “entelodont tooth” to see some, as there are no images in the public domain I can use here)

When the grad student found the entelodont tooth, another joined her to search the area all around it. But it was a lone tooth, probably washed from the full skeleton by water. As entelodonts were alpha predators, the teeth and bones wouldn’t have had the typical distribution of prey animal fossils.

There is such a thing, though I don’t know if there’s a mathematical description of the dispersal of bones. Because we were hunting fossils in a rural area, there were plenty of chances for the paleontologists to keep track of local predator kills. If a fox killed a rat, the kill was left alone, and a scientist would go out twice a week and check out the way the bones were being pulled away by scavengers. He might pick one up briefly to study tooth marks in the bone, but he’d carefully replace it where it had been. In two months, he’d have a movie running in his head of the way the bones dispersed, were trodden, moved away from one another. And that knowledge, he’d apply to hunting for fossil bones.

A.Weith, Wikipedia. Predators disperse bones

Some fossil bones are dispersed like that. Some are not. One of the easier ways to find them is when they’ve been dragged into a den of a dog or weasel or extinct burrowing creodont. Then you might find a whole bundle of them together. But watch out! You might be looking at the bones of four different kills, so it takes care to identify them all correctly.

Local hunters know that the scientists here are always on the lookout for recent kills. Sometimes, they also bring in a dead animal, and the lead paleontologist takes it home, boils it up (outside on the grill, his wife emphasized during a party she hosted) and turns it into only bones. The bones are set out, dried, and labeled. We use these to examine the processes and notches and foramina -- bumps and holes on bones -- to compare to fossil bones we find. Is this single fossil bone, unattached to anything else, an tarsal or a coccyx or something else? Modern anatomy comparisons can help identify this and give a basis for comparison of animal size. A cabinet in the museum is dedicated to modern bones used for this purpose. Bobcats, martens, beavers, a dog killed on the road, and more each have their separate box, filled with smaller boxes of bone groups, each carefully labeled.

“Carefully label” might as well be the job description here. I’ve learned some of the work of a curator of a fossil collection during my time here, too, and the working in a computer system used throughout the federal government for natural history collections. I’ve done spot checks on inventory. Pulled out specimens for visiting scientists to study. Pulled out rare specimens to be cast and sent to other museums and universities, either for study or display. Some sharing of actual specimens takes place, but if they are needed, they are quite rare, and instead of parcel service mailing, sometimes a skull is driven, in a carefully padded box, eight hundred miles, under the watchful eye of a professional, before it is handed over to another trusted professional. When she’s done with it, she has to drive it back. Parties are de rigueur on both ends of that trip. (Paleontologists party. A lot.)

Fossil collection drawer, much like the ones I worked with

“What are all these fossils worth?” some people ask. The truth is, I don’t know. Serious scientists don’t value fossils in dollars, and they don’t buy them, and they frown on any museum that does. That encourages pilfering and, as I mentioned a couple of posts ago, amateurs stealing fossils out of the ground means that nothing can be learned from them. Sure, the kiddies at the Field Museum might be impressed by the display...but it’s irresponsible of the museum to pay cash and drive an illegal trade in fossils. And quite frankly, the kiddies would have been equally impressed with a plaster replica as with a true fossil skeleton. I’ve caught the disdain of the scientists here for the few big natural history museums that engage in cash exchanges for fossil bones. And don’t ask them what they think of fossils sold on E-bay, not unless you want a ranting earful.

Knowledge is priceless. To the scientists I have met, putting a dollar value on a fossil is like putting a dollar value on a kid’s love for his grandma. Impossible to quantify.

When I have made sure the paperwork is all in order, I leave as quickly as I can to get into a shower. I’ve never taken showers this cold before, but my body is so overheated by the end of the afternoon in the searing canyon, I need it. I shower until I shiver. Then I rehydrate.

Tomorrow I’ll come back and work on the second part of the process, making a fossil found two years ago come fully out of the rock it was in.

(series will finish next week)

Hunting Fossils, part 2

The kids--graduate students, but I’m getting to the age that anyone under 30 could be a kid of mine--are already settling in. I ask Marcie, the permanent worker in charge, if I can take a specific pile of rocks where no one else is working, and she okays it and marks it on a detailed map and in her expedition log. I watch my feet as I move off the trail, making sure that I don’t step on a fossil. There’s a bit of shade not much larger than my boot to the right. I check the spot for fossils and snakes before shoving my pack in there. I’d rather drink water that’s 100F than some that’s 140F, and that’s the difference the shade will make to my water bottle.

A canyon much like this: Wikimedia Commons, Peter1dav

The tools I’m most likely to need are already on the belt I wear, so I grab the rock hammer from the pack and sit down at the base of the hillock of packed gravel. I’m not going to be banging the rock hammer against anything. I use the tip to gently move loose rocks.

I’ve been told to keep a careful eye out for tiny bones, like rodent bones. “A bat would be great,” the lead paleontologist told me, and I had to look up what a bat skeleton looked like to imagine what I might be looking for. Lots of thin, thin finger bones. Pretty scary looking monster without its flesh. And the tiniest sharp teeth. I despair of finding one of those. It could easily be mistaken for a shard of mica. The slender finger bones would be unlikely to survive, but you never know. A skull or jaw, quite possibly. I’d memorized what they looked like.

I like this time of day, working before the heat feels as if it might literally kill me. I’ve asked to start at 6 a.m., but the grad students don’t wish to give up late-night partying, and the permanent workers don’t believe they can start then anyway; they are government workers, and if there’s anything the government is bad at, it’s logic. Better to kill a couple G5s in afternoon heat than to change the work hours! So this is as good as it gets, temperature-wise, and I appreciate the relative comfort while I have it.

Early mornings and late afternoons are also better for hunting because the sun comes in at an oblique angle. The way the light hits a fossil tooth or a fragment of still-shiny fossil bone makes it reflect sunlight back at you. You can see more of them when the sun is low than when it is directly overhead.

In fact, over where Marcie is working, I see a glimmer right in front of her boot. “Hey, I think there’s a tooth or bone right in front of your right boot,” I say. She reaches down. “About three inches out from there,” I say, then, “Now an inch to your left.” She finds it. “Yeah! Rhino tooth. Good eye.”

I don’t have a good eye, actually. Perhaps if I had more than five months at this work, I could learn to have a better one. But some people have visual acuity that allows them to pick one slightly different tiny bit out of many similar tiny bits. I’ve showed the seasonal rangers how fossils look in situ, by walking up to them with a handful of rocks and one tiny fossil that I carefully selected, bringing its bag and label with me, so I didn’t remove it from its data. “Pick out the fossil” I said to them. They couldn’t. The rock and the fossils are much the same color, and it is that trick of light that let me see the tip of the tooth. I haven’t a good eye, as Marcie said, but good luck--though as scientific as paleontologists are, many of them believe in fossil luck, too.

I comb through my small pile of rocks. I won’t leave this six by six mound all day. And someone else could re-examine it tomorrow and probably find ten fossils that I missed. I find several. One is a bone that could be the toe of something medium-sized or the humerus of something tiny. Even the grad students would have a hard time deciding which; it’ll take a more experienced paleontologist to tell what it is.

I find an oreodont tooth. Oreodonts! If the people are right who say only 1 in a million of individuals of a mammal species are fossilized, then once North America must have been wall-to-wall oreodonts, grazing every square inch of grass from Minnesota to the West Coast. (A West Coast that was some hundreds of miles east of where it is now, by the way.) There must have been herds of tens of thousands moving together. This is only one of many working fossil sites in North American filled with them, and there are sufficient skulls in the collection that I think it would be enough to build a decent-sized storage shed made of nothing but oreodont skulls. It’d be pretty, I think, but the scientists wouldn’t allow that to happen. So here’s yet another tooth.

I also find three fossilized dung-beetle brooding balls. Those are plentiful enough in these parts that we could build a whole city with them. If you have hiked a good deal, you have probably stepped on a few hundred yourself. I imagine armies of dung beetles, hurrying around under the endless herds of oreodonts, gathering up their dung to make the balls, laying their eggs inside, and moving on to make the next baby-dung-beetle incubator.

A modern dung beetle with ball

Today, it is just us five people here among the bare rocks--us and a few rattlers keeping themselves well hidden. But this bleak canyon was once a grassy landscape that teemed with life.





(To be continued)

Zooniverse.org

A month or so ago, when I had my writing work done for the day, I looked at email and there was a notice from zooniverse.org. I did an hour of work immediately and made a minor contribution to science. Not bad for a slow afternoon.

If you don’t know what Zooniverse is, it’s a coalition of scientists who have projects that they need a lot of human eyes on. Online volunteers provide the eyes. I believe the first project was “galaxy zoo,” identifying galaxies in deep-space Hubble images. I participated in that for a time, when I had internet and spare time. Along the way, I’ve also taken part in:

Snapshot Serengeti: Wild animals (and a rare human) trigger still cameras, and you pick out what animals were caught in the shot, how many, and what they were doing. 

Whale Song: There is a classification system for whale songs (who knew?) and I listened to several and tried to classify them within that system.

Shakespeare’s World: I turned some handwritten letters from the Elizabethan Era into computer files. The content of the letters was interesting. Parties, family, food, politics were among the topics. I assumed beforehand that the language would be quite different than our own, but it was quite similar.

Operation War Diary: WWI field notes. This was far more interesting than I thought it would be. I gravitated to the medical officers’ and ambulance teams’ notes and learned a good deal about wounds, mental illness and STDs in WWI. (Spoiler alert: soldiers get VD. A lot.) Both this and the Shakespeare era letters reminded me of how important primary documents are to historical novelists. You learn a lot of detail by reading, not necessarily what you’re looking for, but all of it adding up to the world coming alive in your mind.

Cyclone Center: Identifying satellite images of hurricanes in their various stages. Despite knowing something about this topic, I found this one tough.

Arizona Batwatch: The “Arizona” drew my eye, and I watched several ten-second clips of bats flying around the entrance to their homes, counted the critters, identified moments of hovering, of bumping into each other (they do!) and the rare landing caught on film. I found a double landing my first afternoon--and the first afternoon of crowd sourcing the project--and the scientists running the project were clearly stoked about it. A scientist who is working on that area of research will be very happy to know which clips to look at to study the landings in more detail.

Computers can pick out some meaning out of data (computers discover most comets these days by comparing images and seeing the dot that shouldn’t be there, for instance), but they can’t do what the human eye and brain can. Certain patterns are too complicated for even the best computer programs to analyze. Only our minds and eyes can do it.

In my youth I didn’t have the opportunity to study much science after high school, and yet I’ve had the chance to do some later in life through volunteer opportunities, both real life and online. At Zooniverse, you too can do real science. Don’t have a PhD in it but love astronomy or biology? You can still add to humanity’s knowledge about that field. Volunteers have discovered new types of galaxies, distant supernovae, and more. You only have a half-hour per week, or even less time? No matter. You can still help unlock Nature’s secrets. G’on over and take a gander. You might find something that calls to you.