This Podcast Will Kill You - Special Episode: Coprolites!

Episode Date: May 17, 2022

Our tapeworm episode last week mentioned the remarkable finding of tapeworm eggs in a 270 million-year old shark coprolite, that is, fossilized feces. And this certainly wasn’t the first time coprolites have come up on the podcast; we’ve referenced them several times before, mostly when discussing early histories of parasitic worms. But there is so much more to the world of coprolites than just which parasites were found and when. To help us explore all that coprolites can teach us is the world-renowned paleontologist Dr. Karen Chin, Professor at University of Colorado Boulder and Curator of Paleontology at CU-Boulder Museum of Natural History. In this exciting bonus episode, Dr. Chin takes us on a fascinating tour of the what (what are coprolites?), the why (why are they important?), the how (how do feces get preserved?), and the who (who dung it?) of these incredible trace fossils. See omnystudio.com/listener for privacy information.

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This is a job for Indeed Sponsored Jobs. Hi, I'm Aaron Welsh, and this is, this podcast will kill you. and you're listening to the latest episode in our mini-series of bonus content that we've been releasing over the past couple of months. We're nearing the end of these bonus episodes for now. We've got just one more planned after this, but that doesn't mean that we won't come back with more someday. In fact, we'd love to do that. Because these episodes have been so much fun and they are such a great way to explore even more deeply a topic we covered in our regular season episode. For instance, we've been able to dig deeper into the world of the Epstein-Barr virus after our

multiple sclerosis episode, learn about how koalas are impacted by chlamydia, understand more about the stigma and discrimination experienced by some people living with hepatitis B, and so much else. In this week's episode, we're deviating a bit more from our regular episode topic than we usually do, but I think that makes it all the more exciting. Because this bonus episode, cover something that Aaron and I have frequently mentioned and expressed our love for on the podcast, but have never taken the time to explore in more depth, and that is Coprolites, aka fossilized feces. In our episode last week, we talked tapeworms, mostly about the tapeworms that commonly infect humans, but those tapeworms only represent a teeny tiny part of the puzzle of these parasites. As we mentioned, tapeworms are an incredible incredibly ancient and highly diverse group of parasites, infecting thousands of animal species all over the globe. We're learning more about these amazing creatures all the time, from the discovery of new species, expanding what we know about present-day tapeworm ecology, to the identification of tapeworm bits in fossils,

filling in some of the gaps in our knowledge of how these parasites and their hosts have evolved. And it's the second part, the fossil part, that I really want to focus on for this bonus episode. If you listened to our tapeworm episode last week, you may remember me mentioning a study from 2013 that found tapeworm eggs in fossilized shark feces from 270 million years ago, which is so incredible. Not only for the simple fact that we can look at and examine poo from millions of years ago, but also because this finding completely revised what we know about the timeline of sestoed evolution in the history of intestinal parasites. And that's typically how coprolites come up on the podcast, when we trace back how far a

human parasite relationship extends or examine how historical distributions of parasites differ from those of today. But coprolites are much, much more than a tool for understanding parasite evolution or host parasite relationships. These magic packages, as my guest for this episode has called them, can yield incredible amounts of information on the typical diet of an extinct animal, the ecological relationships among species, and the environmental conditions near the time of fossilization, among other things. Although people have been studying coprolites since the first decades of the 1800s, some of the most impactful discoveries in this field have been made

in just the past few decades by Dr. Karen Chin, who is one of the world's leading experts in Coprolites. Dr. Chin has so graciously agreed to let me ask her all kinds of questions about fossilized feces today, and I am incredibly excited to dive in, so let's just take a quick break here and get to it. Dinner shows up every night, whether you're prepared for it or not, and with Blue Apron, you won't need to panic order takeout again. Blue Apron meals are designed by chefs, and arrive with pre-portioned ingredients so there's no meal planning and no extra grocery trip. There, assemble and bake meals take about five minutes of hands-on prep. Just spread the pre-chopped ingredients on a sheet pan, put it in the oven, and that's it.

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to get free shipping and 365-day returns. quince.com slash this podcast. My name is Karen Chin, and I am a professor at the University of Colorado, Boulder. And I'm also curator of paleontology at the CU or University of Colorado's Museum of Natural History. I study ancient ecosystems, and mostly I focus on Mesozoic ecosystems, which is the time when the big dinosaurs were roaming around. Awesome. Thank you so very much for joining me today. I have been absolutely fascinated by coprolites ever since learning about them during my master's in reading about hookworm eggs

and the peopling of the Americas and all the things we can learn from fossilized poop. And I've always wanted to dig in a little bit deeper and explore more, especially of the non-parasite side of things. So I am really thrilled for this interview. Well, thank you. Thank you for inviting me. Of course. So could you start us off by defining the word coprolite?

Yes, I can. A coprolite is fossilized feces. Sometimes people immediately think it has to be from a dinosaur, but it could be from a fish or a human or an insect. It just means fossilized feces. And there's a whole variety of them. But I would say that since I work on very old fossils, say, most of the fossils I work on are over 66 million years old.

But coprolites can be preserved in what I would call young sediments, only a few hundred years or a few thousand or a million years old. And how they are preserved often depends on their age. So what the kind of coprolites I work on are hard, they're mineralized. Whereas if you talk to an archaeologist, many of the coprolites they work on are still, they were preserved through drying, through desiccation. And if archaeologists rehydrate them, they can still have. have odors where most of the material we work on is mineralized.

What do coprolites look like? I'm sure there's not a one-size-fits-all answer to this question. And so how variable can they be in their shape and size? That's a great question. They're highly variable. And their variableness often depends on how big they are. So if you're talking about little feces from insects or or shrimp, they often have a very predictable size and shape. But if you're talking about feces from, say, a duck bill dinosaur, often they just do not hold their shape, either when they're deposited or when they're trampled. and you can see that yourself if you go to the zoo and look at the elephant dung. One or two of them might be have a nice round shape,

but many of them are just kind of trampled and have no recognizable shape. So the shape is usually dependent on the size of the animal. And then within that, when feces are first produced, they can be, oh, little teeny pellets, they can be ovoid, they can be more like a cow pie, they can be really irregular. And this depends, again, upon the size and also upon the diet and the kind of animal that produced it. Coprolites are a type of trace fossil, right?

So what are some other examples of trace fossils and how does the information that we can get from these type of fossils differ from the info we can glean from something like a body fossil, for instance. Yes, that's a great distinction. Body fossils are part of what the animal looked like or a plant. I shouldn't limit it to animals. Petrified wood is a kind of body fossil because that's part of what constituted the structure of the animal. In contrast, trace fossils, we record behavior of different organisms. So tooth marks in, say, bone or bro's in the sediment, or footprints or coprolites, they all record some kind of behavior. And they tell us, they provide different perspectives because with body fossils, we can try to envision what an

animal or plant or whatever looked like, some kind of organism, what they looked like. But with trace fossils, we can see, oh, they burrowed here, they burrowed in this manner. What were they doing? What did they eat? How did they walk? How fast did they run? There are different kinds of questions, but they enrich our understanding of ancient life. Of course, everyone and everything poops, generally speaking.

But, you know, what's in that poop can change substantially from day to day. And so if a trace fossil like a coprolite is capturing like a snapshot of an image, a snapshot of what that animal ate and that particular day, what and what happened to just be preserved. And so how does that affect our interpretation of what we see inside that coprolite? Well, I like that you use the phrase snapshot. We like to use that too because it's just kind of a single frame in the whole movement. of ancient life. And sometimes it can be representative of the past and sometimes maybe it was an aberrant situation. Maybe it would be like if you looked at my diet on a day that all I wanted to eat was ice cream. That might not be relevant for my normal diet. So you mentioned, of course,

that the size of the animal and the type of the animal can really affect what the coprolite looks like simply because of what's in the poop and so on. But how does that affect how coprolites form? Well, I guess my first question is how do they form? And then the second sort of add-on question is how do things like animal diet or the environmental conditions, how do those things play a role in whether or not that poop becomes fossilized? Yes, all those factors are super important. If we go back to thinking about archaeological samples that are only maybe hundreds or thousands of years old, those can preserve in a very dry environment, say, in a cave. But if you're talking about older material, the most common method of feces being

preserved. And it sounds crazy that we could actually preserve soft material like feces. But if it becomes mineralized, it can preserve it in three dimensions. So the diet actually plays a major role in whether ancient feces were mineralized or not. Because if you're a carnivore, if you feed on vertebrates that have bones or something that has only soft tissue, either way, there is phosphorus in bone, there's phosphorus in soft tissue, and that can contribute to the mineral called calcium phosphate. And there's a lot of calcium around, so that's a little easier to come by, but phosphorus is not so easy to come by. So if you are a carnivore and have a diet that has phosphorus in it, your feces are more likely to be preserved if they are deposited in under the

right conditions. So that means that most of the feces throughout the world in museums are mostly from carnivores, which is kind of counterintuitive because they're far more herbivores than there are carnivores. But herbivore coprolites require an external source of elements that that can help them be mineralized. So actually, herbivore coprolites are very, very rare. And in terms of the environmental conditions at the time, or maybe environmental conditions nowadays, are there hotspots that we see around the world

where there happens to be a lot of coprolite deposits? Yes, indeed, the hot spot would actually be the likelihood of whether something is buried or not. And this also works in terms of preserving body fossils. Most fossils can be more easily preserved if they are rapidly buried. And that goes for feces as well, because what happens is if the feces are left exposed on the surface, they can be subjected to rain, so an erosion or,

animals that step on it or feed on it or other things that just decay it. It can be decayed by bacteria. If you bury the feces, you can slow bacterial decomposition. And if the conditions are right and we're still trying to understand what those conditions are, bacteria can actually facilitate mineralization of the soft material. And again, this seems, ironic because bacteria, you usually think of bacteria as decaying things. But as bacteria live, they can produce some substances or change the microenvironment that actually facilitates mineralization. And many experiments have been done investigating the role of bacteria in mineralization.

And it may be that many, maybe even most processes, of mineralization in place, and I'm talking about in sedimentary environment, I'm not talking about volcanics or magmas or anything, but just producing chemical minerals in place seem to be facilitated by the activity of microbes, especially bacteria. And are those bacteria, are they environmental bacteria or like in the soil, or are they internal bacteria as part of like the gut microbiome and shed along with the feces. We are still trying to figure out which bacteria can do this. The thing about feces is feces have so much, so many bacteria in them, but there's lots.

So they can be readily preserved if the conditions are right. which bacteria. That's an excellent question. A student that I worked with, Dr. Joseph Daniel, he once did an experiment with me where he buried chunks of bone and then dripped a super saturated solution of calcium carbonate over the bone. But some of the pieces of bone had been treated to reduce the numbers of bacteria. It's hard to get rid of everything, but he reduced a lot of them. In the chunks of bone where the bacterial populations were reduced, there was very little precipitation of the calcium carbonate

that was percolating through the sand and around the bones. Speaking of bacteria, most of the time when we've brought up coprolites on the podcast before, it's been in the context of parasite eggs, specifically human parasite eggs that have been found in certain specimens, where and when, what does that tell us about human evolution or parasite evolution? But coprolites can tell us a great deal more about the animal that produced that poo than just what parasites they may have been infected with. So what are some of the other things that we can learn from coprolites? Yes, we can learn several different things. And it, usually depends on the kind of preservation of the coprolite that you're examining.

I think the most common source of information we look for is what was the animal eating. And sometimes we can recognize some very distinctive bits and pieces. And you have to kind of think three-dimensionally because quite often when you're looking at dietary residues in a coprolite, they've been chomped, they've been digested with gastric juices, and then they've probably been changed through geological processes, through mineralization or by bacterial decay. So we look for bits and pieces that can give us a glimpse into who were the victims, who was eaten? Sometimes we see pieces of bone, sometimes we see pieces of shell, Sometimes we see lots of leaves.

And sometimes those things are very, very difficult to recognize. But we're getting better. And sometimes we can see just a little piece of something and say, well, that's a piece of bone. In most cases, we assume that when we find something in a coprolite, it was eaten. It was food. But sometimes we can also see evidence of organisms that were visitors that visited a dung pile after it was deposited. And actually one study that I worked on with colleagues,

we found over 140, I don't know, more than that, snails associated with coprolites. They were preserved in them, on top of them, and we examined how complete they were and actually found that most of them were fairly complete. So this suggested that these snails were post-depositional visitors because snails actually often feed on dung, snails and slugs, because they like the bacteria in dung.

And sometimes when people are studying snails, they will put dung out for bait to attract them. So that indicated that in this case, even though we found snails in the coprolite, they were not necessarily eaten. It's possible that some of them were eaten, but it appears that most of them visited the dung after it was deposited. So this provides another angle of interpreting the ancient environment because this shows how waste materials like dung were recycled in ancient environments.

So we have diet, we have recycling. we can also just tell, you know, if something is eaten, it's a contemporary of the dinosaurs. So we can learn who was living with the dinosaurs, whether or not they were eaten. And finally, well, I shouldn't say finally. We're still finding more and more about what coprolites can tell us. But I'd say of the fourth major category is when we study some coprolites, we can learn how it was preserved. And a good example of this, the best example that I have worked on, is when we studied a Tyrannosaur coprolite, not T-Rex, but a slightly smaller and older relative,

probably 10 million years older than T-Rex. And when we examined the coprolite, we found mineralized muscle tissue. This was just, ah, there, was so shocking because you'd expect, wait a minute, this can't be. This went through the dinosaur's gut and then it came out. And you'd think that somewhere along the way, it was the muscle tissue was either digested or else decomposed by bacteria. But what this told us was that the gut residence time of the food was rather quick. If the food had just sat in the dinosaur's gut for a long period of time, it would have been more completely broken down.

But if it went through relatively quickly, you wouldn't necessarily have digestive juices actually attacking every little bit of what was eaten. And when I was working on this, I found an article that explained that muscle tissue has been found in the feces. of dogs that were fed raw meat. And you figure if a dog has a skull that's maybe a big dog, maybe has a 10 or 11 inch long skull, but a Tyrannosaur could have a skull with three feet long and they could not chew like a dog could. They could gulp and swallow.

So if there was a relatively fast gut residence time, all of those bits of food would not necessarily. be digested. And then once it was deposited, we have to mineralize it very quickly before all the bacteria decompose the muscle tissue. But again, as we've learned, bacteria can facilitate mineralization. And there have been scientists who have taken dead animals like dead shrimp and buried them. And they have documented mineralization of the muscle tissue within weeks. So all of these things tell us about a little bit about the digestive tract. They tell us about the process of mineralization.

And that was not originally why I wanted to study this, Toronto's orcopro. And I wanted to learn about the diet, but it provided such an interesting window on other kinds of aspects of the fossil record. That must have been so thrilling to see that muscle tissue, what an unexpected finding? It was such a fun study, but it was, it was challenging because when I first saw it, I thought, that doesn't look like plant tissue. Maybe it's muscle tissue. No, it can't be. It just can't be. And I'd go to bed at night thinking it's not muscle tissue. Then I'd wake up in the morning. Maybe it could be. Then I, the next day, I'd think, no, it's plant tissue. And I'd wake up in the

morning. No, it could be muscle tissue. And so because I'm not a specialist in anatomical tissues, I sought out a colleague at Stanford who actually worked on muscle tissues and shared it with him. And Dr. Randow said, yes, I think this seems to be the most likely explanation. So it was, it was so surprising. But interestingly, as I was making, looking at the microscope through thin sections of this specimen, I suspected that it was muscle tissue, but then one day I happened to make some random thin section and could actually see the myofibular striations in skeletal muscle tissue. But that was so serendipitous to get just the right angle and the right view. And that really helped seal our interpretation. And so is that one of the major ways that you study coprolites

is through, you know, taking this fossil and cutting tiny little slivers, little sections and putting them on a microscope? How are, what are some of the other ways? Or if you could talk a little bit more about these methods that you use to study these coprolides? Yes, I really like making those thin sections like you explained, but it is a destructive process. And before you ever do anything like that, you have to, first of all, ask the museum for permission to destructively analyze some of a sample. And you often don't necessarily want to do too much of this, especially if it's a very unique specimen. So that is one way we do microscopy on broken pieces.

But one thing we are investigating now is looking, using computed tomography or CT to examine what's inside. And I and my students have used x-ray computed tomography and neutron computed tomography. And one of my colleagues in Europe, Dr. Martin Farnstrom, has done exceptional work in using synchrotron radiation. And then he's been able to find really cool beetle parts in some of the coprolites and other things in some of the material he's studied. And that is really great because it's non-destructive. But there's pros and cons to both methods. I think sometimes you can see more in a thin section, but you're only looking at a two-dimensional

slice, and it's destructive. With computed tomography, you're seeing three dimensions, but you may not necessarily see cellular detail that might be preserved. So we're throwing as many different techniques at these coprolites to learn as much as we can. And what we are learning these days, I imagine in 20 years people will be able to do so much more information. One of the things that crossed my mind was that you're able to tell so much from this coprolite, but how can you use that information to help you determine what animal it might have come from? Is it just from the coprolite itself, or is it also from what else you find in the area? Yes, this is another time when we use multiple lines of evidence.

The most important line of evidence is what is the age of the sediments. So if I'm looking at Cretaceous age sediments, I know that only a certain number of animals could have produced it. I won't say it could have been produced by a woolly mammoth because they didn't live in the Cretaceous. And then you can fine tune that so that when you find a coprolite, you're looking at maybe just a, What are the contemporaneous organisms that we find in the sediments of the same age? So that is one line of evidence. Another line of evidence is the size. If you find a really large fecal deposit, you know it wasn't produced by a small rodent

size mammal. If you find a small piece, that's a little more difficult because small pieces can come off of a larger fecal mass. And there are, we know, things like deer and rabbits that often produce pellet groups. The complete pellet mass is different from the mass of one of those little pellets. But size is helpful. And then what is inside, if we find bone inside, we know we're not looking at an herbivore. So you use all of those different lines of evidence.

And when we actually studied a very likely T-Rex coprolite, we measured the volume of it, and it seemed to be about two and a half liters in volume, roughly two and a half quarts. And this would be a very large fecal mass. So we looked at, well, who else lived? Who lived in those sediments that was a carnivore since we knew there was bone in there? And we found that many of the animals fell into kind of two groups. One were carnivores that were maybe a couple hundred pounds roughly. And then there was T-Rex that was much, much larger. So between looking at the animals that lived at the same time,

the fact that there was bone in the diet, the size, we were pretty confident that this fecal mass was produced by T-Rex. But with a cockerolite, you often will never know. It's quite possible that a large animal that was not T-Rex passed through the area at the time, defecated and did not leave any bones behind. So always when we talk about who produced a coprolite, I always put probable coprolite from such and such an animal in front of it. I love the idea of a big dino just passing through and just dropping off a coprolite and keep going and like leaving people nowadays.

Like what could that have been besides T-Rex? Exactly. And so that that T-Rex, that likely, that probable T-Rex turd, is that the largest coprolite found? No, no. We've since found coprolites that are on the order of six to eight liters in volume. And that's just the ones that I have looked at. I know other people keep finding large coprolites that may or may not be published at this point. But I'd say those are among the largest we found. So you've talked about two Tyrannosaur coprolite stories, which I think are super. fascinating, but I wanted to ask you also about another of your groundbreaking findings, which is the duckbill coprolites from the two medicine formation. What did you learn from these coprolites about duckbill diet and maybe dung beetles? Yes, this was one of my favorite studies. We found,

well, I should say it was my boss and mentor Dr. Jack Horner that originally found, these weird rocks that had lots of plant tissues in them. So for my doctoral dissertation, I studied, what is the evidence that these are actually coprolites that like Jack thought they were? And we found good evidence that they were from the geological evidence and the contents. But another aspect of these coprolites that was so interesting is that many of them had burrows. in them. And I immediately thought, oh, dung beetles. But then I thought, well, I'd never be able to tell a dung beetle burrow from a worm burrow. So I can't say that these are dung beetle burrows. But when I was studying this project, I was contacted by Dr. Bruce Gill, who was a dung beetle specialist from

Canada. And he asked about the burrows. And I just said, well, yeah, there's burrows, but we can never tell who produced him. And he said, well, why don't you send me some photographs? And I did, and he explained that these burrows are very distinctive, and they're in modern environments. We don't have animals that backfill sediment with dung to provision these brood masses for the young beetles that will be growing up. And so the dung beetle burrows have very distinctive features. And he looked at them and said, those are dung beetle burrows. And so that was really, that was really a lot of fun because it linked the dinosaurs not only

with the plants they ate, but with the community of recyclers. We found, we studied these burrows before we found the snails. But as we keep learning about these animals that are associated with the dung, that actually opens up more and more intriguing views of the ancient environment. In fact, one of the thing, not only did we have the dung beetles, but these, these coprolites were filled with wood, conifer wood. And I thought my first publication, I thought, well, if these dinosaurs are feeding on conifers, cone-bearing trees with very short needles, say like junipers or other kinds of, you know,

conifers with very little leaves, of course they're going to eat lots of wood. But after further study, I realized that the pieces of wood did not course. respond to the branches that you would expect if they were feeding on the leaves. And after more study of the cellular structure of the wood, it became evident that the dinosaurs had actually ingested rotted wood. And this is, it seems surprising. A lot of people will say, well, maybe it just rotted in, maybe the structure of the cells occurred in the dinosaur stomach, but it gets a little complicated, but I'll just say,

in order to get the cell structure we found, you have to destroy a component in wood called lignin. But to do that, it requires oxygen. So that cannot happen in a vertebrate gut. So the structure that we find in the coprolites, where you find the cell structures are broken apart could only have been done by a white rot fungus that would have occurred before the dinosaurs ingested it. So then you say, well, why were they eating wood? It doesn't make sense. But when you decay wood with fungus, you actually make cellulose available so the wood

becomes more nutritious. But still, it doesn't seem, why would they eat wood when they could go out and eat leaves? Because there's cellulose and leaves, and that seems like an easier source of cellulose. But at this point in time, our best hypothesis is that the dinosaurs were nesting and required sources of protein to help support when they laid eggs. they needed to add enough protein to those eggs. And if you're a big herbivore, probably the best place that you're going to find a reliable source of protein that you can actually catch, since you're not a carnivore,

would be something like rotting wood, where there'd be termites and crustaceans and all kinds of very interesting animals in there. So this built, again, we have the dinosaurs. We have the conifer wood. We have the white rot fungi. We have the dung beetle activity. We have the snails. And then some colleagues found comparable coprolites in southern Utah.

And in those coprolites, there were pieces of crustacean. So this really kind of supported the idea that, yeah, these animals, even though they were herbivores, did occasionally. eat animals, just like most birds are tend to be, even if they're mostly herbivorous, they will often change their diet when they are getting ready to reproduce. That is so incredible how you can build this world and paint this picture from one, like from these fossils, this fossilized poop. It's so beautiful. I love it. I just love that. That's amazing. I think it's pretty cool. Yeah. And oftentimes people will think that coprolites can't tell us that much. And they're right. Some coprolites do not tell us that much. But some coprolites, just because of what they're composed of and how they're preserved, can provide incredible snapshots that give us a view on ancient life. We're going to take a quick break here. And when we get back, I want to hear all about how you were introduced.

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Our programs are designed for people who never stop. You bring the fire, APU will fuel the journey. Learn more at APU.appus.edu. Welcome back, everyone. I've been really enjoying hearing all about the science of Coprolites, but now I want to hear about you. How did you become interested in fossils in the first place? Were you one of those kids that just love dinosaurs,

or did that love kind of spark later on? I really thought dinosaurs were cool when I was growing up. I had like many young kids. I had a dinosaur book, but I never really thought. I never really envisioned myself studying dinosaurs when I grew up. I was interested in the modern world. You can walk out your door, look at plants and animals, and I just thought it would be so frustrating to try to study something that we can never see. see again. So I was really quite surprised by my reaction when I started working for Dr. Jack Horner. I was working as a preparator cleaning and gluing dinosaur bones together. And then I went out and visited their field camps. And I started also researching paleontology to help write text for the

exhibits. And the more I learned about it, the more I was, I was, I was hooked. I just, I couldn't get enough of it. And it was so ironic because, again, I never thought that I would study something like that because I really thought it would be too frustrating. But instead, it just, different people have different affinities for different subjects. And I found that this studying paleontology really fit the way I think. And when did coprolites come onto the scene? What was the first coprolite that you remember looking at or studying? That would be the ones from the two medicine information that Jack found.

And I never even thought that feces could be fossilized. It wasn't until I was reading and writing exhibit text that I learned that people had found it. And so I ran to talk to Jack and I said, did you know that people have found fossilized feces? And he said, well, yeah, and I found some too. And I was just shocked. And so I said, well, at the time I was working as his histological technician. So I was cutting up bone pieces to look at the patterns of vascular tissue so he could make inferences about physiology and phylogeny. of dinosaurs. So I was already used to cutting fossil mineralized samples. So I said, well, can I

cut a piece of this and make a thin section? And he gave me permission to do so. And when I looked into the microscope, I looked at that slide, I could see ancient plant cells. And it just kind of, it was a real thrill because I realized I was looking at evidence of plant dinosaur interactions. And what a cool way to look at how dinosaurs interacted with other organisms in environment. And that's when I got hooked. You are an absolute pioneer in the field of coprolites. How have you seen this field change over the course of your career, either in terms of technology or just generally speaking? Well, I have found some interesting things.

I studied some interesting. projects in coprolites. But I don't know. I would like to point out that people knew about fossilized feces before they had ever named dinosaurs. So over 100 years, and there have been many, many people who've done some really cool work on on coprolites. So I don't want to claim I'm the only person that was studying them. Lots of people have studied them. But I will say that something Cobra Lites is not easy. It's really hard and it can be very frustrating because unlike with a bone, you can pick up a bone and you say, okay, that's a bone and I can figure out who it was or a shell or wood.

But when you pick up something that you think is a cobra light, first you have to say, well, wait a minute, what is the evidence that this is fossil feces? Some of the material we look at is and some of it isn't. And then you may look at it and find nothing recognizable in it. And you may not know who produced it. So it's really, really challenging. So it helps if you're studying some really spectacular examples. And I have been lucky to study some of those spectacular examples.

But I think that these days now people are looking at some of the even more difficult ones to study. And they have been making conclusions, you know, examining specimens that I may not have started the study before. And finding new things, just documenting things all over the world. People all over the world are studying coprolates. And like I mentioned, my colleague is using synchrotron radiation and people are looking at other ways to study them. So I think it's really an exciting time for trace fossils because quite often body. fossils get most of the attention because they tell us about great big or weird animals. But it coprolates, they're interesting, but they are more challenging to study.

And I'm so pleased that more and more people are studying them these days. One of the things that I really admire about you is just how much outreach and science communication that you do. Can you talk about why you feel it is important for scientists to connect with the public and share their work? I think sometimes people think of science as being a black box, that scientists have these answers to things that maybe some people may not understand how we came to those answers. So I like talking about my work because it's easy for people to get excited, especially kids about dinosaurs. And when you throw in something like dinosaur feces, it's even a better hook to get

people saying, well, that's weird. How can you learn about that? So then when I talk about my work, they can get an idea of how the process of science works. And it might be more approachable for them. And I think this is very important because we all have to, we all should know more about the way science works and why we know what we do so that when we learn, when we get information about changing environments or decisions that have to be made that relate to science, we are better educated ourselves. So I think it's very important for all of us to get an idea of the critical thinking that goes into conducting science and that people understand that we're not pulling weird facts out of the air, that we do do evidence-based research.

What are some misconceptions about paleontology or paleontologists that the general public might have that you would like to correct? Oh, I don't know that there's anything really critical. I'd say that a common misconception sometimes is people think that paleontologists and archaeologists are the same, where paleontologists study ancient organisms, non-human organisms, and archaeologists study human organisms. But I don't even mind if people call me an archaeologist because they know we study old things. And that's fine. Another common misconception, and I don't, again, I don't think it's a bad thing, is that people often think we get to spend all of our time out in the field with our pick in hand and finding new stuff.

And that is so much fun to do. And I should say that I have colleagues that can spend months and months out of the year. But for the rest of us, many of us have to spend more time that we'd like to admit. sitting in front of a computer trying to write up or describe our results. So it can sound very glamorous. And some of my colleagues do have a very glamorous lifestyle. But for the rest of us, sometimes we get to go out in the field for a little while and then spend the rest of the time in front of the computer. But again, I don't mind these misconceptions because I think I just am happy when people are interested in science. Do you feel that?

that graduate students in paleontology are getting enough training in communicating their science to the general public? I do think I see more and more interest in graduate students in learning techniques to communicate the science. I really do think that there is a growing awareness of how important it is to communicate science. And I'm delighted to see many graduate students volunteer to work in museums, to do outreach with people, to go out in the community. And that's a development that I'm delighted about. I've got just one more question for you before I let you go. Do you happen to have a favorite coprolite pun?

I'm sure you've heard many over the years. Okay, well, I'll tell you my oldest one. And because it's the oldest one, I know some of my friends tend to groan every time they hear it, but I'll risk that if they happen to hear this. Cobra lights are very challenging to study, as I mentioned. And because you often do not know, first of all, if it's a coprolite or who produced it. So I often like to tell people that my work is challenging because when I study a coprolite, I may not know who dung it. Thank you so much for joining me today, Dr. Chin.

Coprolites are even cooler than I expected them to be, and I had some pretty high expectations. And I am so excited to do some more reading on the amazing world of fossilized feces. And if you too would like to learn more about the who, the what, the how, and the why of Coprolites, check out the post for this episode on our website, this podcast will kill you.com, where I'll link to a few papers by Dr. Chin. Also on our website are the sources for all of our episodes, transcripts, quarantini and placebo-reta recipes, our bookshop.org affiliate account, goodreads list, links to music by Bloodmobile, links to merch and Patreon, and so much more.

Listen, follow, and leave us a review on Amazon Music, Apple Podcasts, or wherever you get your podcasts. And don't forget, you can listen to new episodes one week early on Amazon Music, or early and ad-free by subscribing to Wondry Plus in the Wondry app. Thanks again to Bloodmobile for providing the music for this and all of our episodes. And thank you to you, listeners. I hope you enjoyed this deep dive into Dino Poop. And a special thank you, as always, to our wonderful Jennings. generous patrons. We appreciate you so much. We've got a brand new episode on a brand new topic

coming out next week. So until then, keep washing those hands. Success starts with your drive. An American Public University is here to fuel it. With affordable tuition and over 200 flexible online programs, APU helps you gain the skills and confidence to move forward. Whether you're changing careers, starting fresh, or pursuing a lifelong passion, our programs, are designed for people who never stop. You bring the fire, APU will fuel the journey. Learn more at APU. APU.orgas.edu. This is Matt Rogers from Los Culture Eastus

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