Hunting Fossils - Conclusion

The fossils we found this month will go into a temporary set of drawers in the museum for further processing. Today, I’m working in the prep lab on a fossil found two years ago.

Many of the fossils we’ve been finding are on the surface. “Digging” for fossils is pretty rare here. There’s a surfeit of fine ones to be plucked off the ground. But sometimes in the canyon, you see a gleam of a tooth, and then an inch or two of curved jaw, and you know there’s something better encased in the rock behind it. Plaster, rock hammers, picks are used to ease the thing out--often over the course of a week or two. It comes out with plenty of extra rock around it.

Wikipedia. A fossil still in matrix

Such is the jaw I’m working on right now. It’s another oreodont. The rock--called “matrix”--needs to come off to reveal the fossil itself. Last week, I finished the top of the skull. There’s a beautiful pearlescent quality to part of it. I hit one difficult patch, but most of this one is coming along easily.

There are people who can do picky, fine work. I’m one of them, so this is my favorite part of the work. (That it’s done in air conditioned comfort is no small part of that.) I can sit for three hours, hunched over a microscope, my work in the eyepiece, and wield the tools of fossil cleaning on the specimen.

The primary tool I use is a pneumatic scribe, a vibrating needle that grinds away the matrix. It takes some practice figuring out the right angle and the right pressure to use--and that changes between the easier fossils and the harder ones, between bone and teeth, between animal and vegetable.

I cheat a little bit today and work at the side of the jaw, the thing that was exposed and let the paleontologist two years ago see it was there. Teeth are so easy to clean, so forgiving. It’s a joy to work at the side of a few molars. And it’s fascinating how different the molar surface is between species. Even I can tell at a glance a rhino from a mammoth from an entelodont from a camel from an oreodont. They each have distinctive cusps, or bumps.

oreodont skull, cleaned

After three hours, I stretch and walk around the museum, answering a question for a tourist. Then I go back into the lab and switch tasks.

I’ve been left with a bag of broken bones from earlier this year. It’s a 3-D jigsaw puzzle, and I’ve put it about half together. I’m thinking I might have more than one bone here. I have enough together I know that one is a vertebra. Naked eye, I gently try a couple of pieces against each other. I move to the microscope when I think I have a fit. I do! Another bit added.

I get out the polyvinyl butyral dissolved in acetone to glue them together, using toothpicks to hold the bones in place until the glue sets. I try another bone fragment in several places, finding no matches, and then I’m done. I put the tray back in my work area. I know the paleontologist comes by and checks my work from time to time, making sure I’m not messing up too badly. There are fossils here so fragile or so important, I’m not let near them.

After lunch, I’m pulled aside to help carve a resting place for a camel’s pelvic bone in a chunk of museum-quality foam. I cradle the bone in both hands, nervous as all get-out, I promise you, as someone else uses an electric knife to match the impression in the foam to the shape of the bone. The knife is just like the one you might use on holidays to carve the turkey.

When it’s ready, we move it out to a new exhibit in the museum. This takes four of us using eight locking suction cup devices to lift a heavy glass case. It’s like a scene out of something like Ocean’s Eleven (minus six), where they rob a museum. First, the guy who was using the knife flips off the alarm system--which is deafening when it is triggered--and then we lift the glass case. It’s heavy. I’m not sure why the alarms, because it really is a four-person job to lift this thing. It’s not something you could sneak in and do in thirty seconds, even if you did your tourism with eight locking suction cup devices in your backpack. Knife Guy rearranges the exhibit and adds the camel bone. He takes out a femur of a different camel, needed for study, and we lower the cabinet, lock it, and he re-sets the alarm.

Wikipedia. Not "my" museum but the sort of case we moved

I go back to work on the oreodont skull. I watch, during the breaks I take to rest my eyes, the paleontologist with the femur bone. She has out calipers and is measuring the distance between various bone markers. There’s some discussion in the field of splitting one camel species into two. If they do that, which is this bone going to be? A pile of scientific journals is open to the relevant pages. She takes pictures from time to time, and sometimes she asks me to hold a flashlight to illuminate a bit of bone correctly.

I’m down to halfway down in the oreodont’s cheek. It has a very deep lacrymal fossa, a dent that held a gland. That it’s so deep will probably help them know exactly what species it is.

I’m stiff from working in one position, so I wander outdoors and walk around. Were it not for the scorching summer heat, it’d be a beautiful day. It’s beautiful for about five minutes until I escape to the air conditioning. Tomorrow, it’s back out into the field, to hunt for more fossils, teeth and bones the hard rock is yielding back up to us.

In the center of the museum entrance is a huge entelodont’s head and neck, the flanges flared out impressively, the fossil teeth sharp enough that there’s a sign warning people not to touch them. Thirty million years after it died, its teeth can still draw blood.

In my time here, I have begun to long to be fossilized. It’s unlikely to happen, but I wish for it nonetheless. It’s as near to immortal as any of us might be.

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)

Hunting fossils, Part I

The sun pounds down on the badlands as I adjust my heavy tool belt and hike on. At the start of the hike, I saw a rattlesnake, too full of breakfast to be aggressive, his meal still an animal-shaped lump under his skin, making me remember the illustration from The Little Prince, the one of the boa having eaten an elephant. Rattlesnakes are a potential problem at the fossil site. There is little shade, and if you try to find a patch of it to eat your lunch, you’ll likely disturb a snake or two. In such a territorial dispute, rattlesnakes always win.

Wikipedia commons. Fossil in matrix (rock)

Even at 8:30 a.m., the sun is relentless. A two-mile hike might have been pleasant, had it not been for the heavy backpack stuffed with bags and rigid containers to hold fossils, plus a small bag of plaster in case a half-exposed fossil needed to be removed from the rock and protected from our efforts to remove it. Most of the weight of my forty-pound burden is water, a full gallon. I’d learned to freeze half of it to help keep my lunch of apple and cheese sandwich from drooping. The belt of picks, brushes, rock hammer, post-it notes, pencil stubs, and plastic pellets dissolved in acetone, used to stabilize small or fragile fossils, is around my waist, so its weight doesn’t strain my back, but I feel its weight on the upslopes. Most of the others in the party with me are newly-minted professionals and twenty years younger. I let them get ahead of me with their excited chattering fading as they go.

I stop to appreciate once again the layer of tuff from the self-detonating eruption of Mt. Mazama, which happened hundreds of miles from this spot. Despite the distance, it left a layer of ash many feet thick, now compressed into this eighteen-inch layer of yellowish tuff. The other rock layers are beautiful pastels, pink and cream and even light blue. If it wasn’t going to be 140 degrees F in the sun later on that day in the canyon, I might appreciate the landscape’s beauty even more. I take off my hat--a critical piece of equipment in these conditions--and fan my sweating scalp with it. The others are around a bend in the trail, and I hurry to catch up.

When I reach the last bench on the trail, I thumb on the heavy radio--another burden of weight--and call the office. “We’re going in, over,” I say. The crackly voice of my favorite ranger comes back. “Have fun. Stay safe. Over and out.” I first tested the limits of the radio over a month ago, and this is as far as the signal will travel. Beyond here, we are on our own. On Day 1 of the work here, I took one look at the sheer cliffs and hard rocks of the fossil site and, a worrier like Hannah, I wondered when someone peeled off one of those cliffs and fell thirty feet, how far I’d have to run to get a signal out for a medevac chopper. This far, I discovered from testing the radio, about a mile distant, probably twelve minutes for me jogging upslope in the heat. My enthusiasm about figuring this out got me designated the radio person for the team.

At the end of the trail, we always look around for hikers and tourists, making sure no one sees where we are going. It’s easy to understand the lure of wanting to find fossils on your own, but it’s a terrible crime against science and public knowledge to take them. A tourist grabbing up some rare sample will remove it from its location, and therefore its date, and therefore all that knowledge about it will be lost forever. In a month or two, the tourist’s fascination with his bit of fossilized jawbone will wane, the thing will gather dust, and his next move across town, it’ll be thrown out as trash. If he calls to return it in a moment of repentance, we couldn’t take it at that point because it is useless without the data its original location would have provided.

To the paleontologists, it’s trash the instant he removed it without recording via camera and GPS exactly where it was removed from. Most important are the photos, one close with a ruler to show the size of the fossil, and one from a distance to show the striations in the surrounding rock. The geologist of the group glances at these photos and he knows from long study which layers those are in this rock formation and what dates they represent.

The layers’ dates have been determined through a complex and expensive series of argon-potassium and argon-argon radiometric tests. Funding for the sciences does not come easily, and the geologist feels lucky to have scraped together those funds. The common person knows about carbon radiometric dating, but carbon dating does no good whatsoever for old rocks. (Or indeed most rocks, which aren’t made of carbon. Carbon = organic material, like soot from a wildfire.) I learned to respect the geologist’s knowledge tremendously in my half-year on this team. He could look at a rock outcropping and know its entire history. In his mind’s eye, the movie played: a volcano far older that Mazama, a plug forming in the volcano during its final eruption, its summit weathering away and leaving the plug exposed, ash from a different volcano falling, the continental plate drifting and pushing the layers askew, more weathering, more ash, a mudflow, compression, until finally the movie led us to today and that precise pile of rocks over there.

The whole time those mostly-slow processes were occurring, there was life here, too. Animals ate, and mated, and fed their young. They killed animals or were killed for their own meat. They burrowed. They climbed. They flew. Inevitably, they died.

Insects ate their decaying flesh. If ash or sediment covered their bones, they might be fossilized. Some experts estimate that only one in a million individuals in any land-based species gets fossilized. The rest break down to their constituent atoms. Under fresh ash, the process of fossilization might go quickly, we learned from Mt. St. Helens and the rapid fossilization of some of the trees there. Under lake sediment, a fossil is hundreds or thousands of years in the making. Molecule by molecule, rock crystal replaces the bone or tooth. Bone and tooth are almost all that survive.  Around the fossil, the land rises. It rains, it snows, winds blow, and the rock weathers.

And that’s why we are here, returning to a rich area once every three to five years (if there is the staff and funding to support that much activity), because new fossils are weathered out all the time. The geologist studies the spot--or at the photo of the spot--where we find a new fossil, and he says, confidently, “thirty to thirty-one million years ago.” The photo and documentation are kept, in case advances in science can correct that date slightly in the future.

No tourists are watching me today, so I follow the others off-trail, down a dry wash into the canyon where we are working all summer long--one canyon out of a hundred in this area. The other canyons’ fossils are being beaten by sun, washed away by rain, and lost to human knowledge forever. But we can only do what we can do. Today, we are to hunt in one tiny section of one canyon for signs of animals of the lower Oligocene.


(to be continued)

Lou Cadle plans for 2017 book releases

Here's the plan for 2017.

New Releases:

• February 10: Dawn of Mammals 5 (last in series, up for pre-order soon)
• April: a very different novel in a pen name, historical fiction, possibly titled Nellie
• May: the pandemic thriller that I drafted back in July 2016
• July or August: a thriller that begins a new series and world. (It’s our world, but a few years in the future)
• October or November: a novel that follows the last one, set several years later, as things go from bad to worse.

Audio books of the Gray series (date of release not yet set), more paperbacks as they are ready, and a Gray omnibus e-book edition will also be released. I'd also like to write sufficient short stories to put together a collection of them. Whew! Another busy year planned.

However, a caveat: authors are human beings. (I know! It’s a shock to hear this news, but you’ll adapt shortly, I’m sure. 😜 ) Stuff happens to human beings sometimes. A grown daughter shows up on the doorstep with a baby and leaves him with you for a year. A heart attack. A house fire. Being kidnapped and held for ransom for six months. Being kidnapped to Tau Ceti to be in a terrible alien experiment on Earthlings. And, to be more positive in my predictions, winning an all-expense paid trip around the world! If any or all of that happens, it could change the schedule. (Do you think I could get a wireless connection from Tau Ceti?)