On Paleontology: Coprolites

Alex Re

Hello, welcome to on wildlife. I'm your host, Alex Re, on this podcast, we bring the wild to you, we take you on a journey into the life of a different animal every week. And I guarantee you, you're gonna come out of here knowing more about your favorite animal than you did before. This week, just like last week, we're dealing with topics and paleontology. And I'm pumped to talk to this week's guest. I got to sit down with Dr. Karen chin, who is a professor and curator of paleontology at the University of Colorado's Museum of Natural History. And she's got some really interesting things to say about some unusual fossils. So you may want to grab your digging tools, because we're going to be talking about coprolites.

So you may be wondering what a coprolite actually is, and you're gonna find that out shortly in my interview with Karen, I can bet that you never even thought about these types of fossils before. But they can tell us so much about prehistoric organisms like the dinosaurs. Dr. chynn got her doctorate at the University of Santa Barbara, and she's one of the leading paleontologists in the world when it comes to coprolites. You can even find her being talked about in National Geographic, The Washington Post and Nova. And not only that, but she also studies ancient ecosystems as a whole, especially during the Mesozoic era, which just happens to be the time period that the dinosaurs were around. Okay, I know you guys are dying to find out what coprolites are, and what insights Karen can give us about the Mesozoic era. So stick around, because you'll get to hear my interview with her right after the break.

The person that I want to recognize in this week's episode of notable figures in science is Daniel Hale Williams. He was born in Pennsylvania in 1856. And he got his degree at Northwestern University Medical School. And his work in medicine was just groundbreaking. Because he was a black man, he wasn't allowed to work in private hospitals. So he founded Providence hospital. And this was the first non segregated Hospital in America. his achievements don't stop there, though, because he's credited as performing the first successful open heart surgery. He was also a member of the Chicago surgical society, and the American College of Surgeons. Williams changed the world of heart surgery as we know it today. And for that, we should be grateful. If you want to learn more about Daniel Hale Williams, or this series, check out on wildlife.org Okay, we're back. Here's my interview with Dr. Karen chin. Hi, Karen, thank you so much for coming on. How are you doing today? Um, well,

Karen Chin

first of all, thank you for inviting me. I'm, I'm It's a pleasure to join you. And I'm doing fine. Thank you.

Alex Re

That's great. That's great. Well, let's get right into it. So first, can you just tell us a little bit about yourself and how you became interested in paleontology?

Karen Chin

Yes, I am a professor of Geological Sciences at the University of Colorado, Boulder. And I'm also at the same university. I'm curator of paleontology at the university's Museum of Natural History.

Alex Re

That's awesome.

Karen Chin

And, but the the story of how I came into paleontology is a little bit convoluted. Because even though I love dinosaurs when I was growing up, I did not think I wanted to be a paleontologist when I was growing up. I love all of the natural world. I love plants. I love animals. I love soils and geology. And so I became a naturalist with the National Park Service, seasonal Park interpreter. And, but somewhere along the way I did I was in graduate school when I met jack Horner, who is the dinosaur paleontologists that everybody knows was the original inspiration for Jurassic Park. Oh, really? Well, well, the movie anyway. The movie version of Jurassic Park? Yes. And I be. I met him and I started working for him at the Museum of the Rockies and at Montana State University. And somewhere along the way, I fell in love with paleontology and just couldn't get enough and I learned I was asking the same questions about Ancient life, as I am interested in in asking about modern life. So that's why it's a little bit convoluted, because like, in the beginning, I couldn't understand why would anybody want to study extinct things? I mean, they're gone. You can't go out there and look at them. But it's, it's really intriguing.

Alex Re

Yeah, that's so interesting. And we're gonna get into talking later about how we can relate today's animals with maybe organisms of the past. So I'm excited to talk about that. But first, so you do a lot of research on these things called copper lights. Can you talk a little bit about what those are and how they become fossilized?

Karen Chin

Yes. Copper lights or copper lights? Are fossilized feces.

Alex Re

Yeah, you heard that? Right. We're talking about dinosaur poop.

Karen Chin

And when I first learned that some PCs had become fossilized. I was really surprised. It seems counterintuitive to think that that something is soft, and ephemeral, as species or dung could be fossilized. But if the conditions are right, they can be fossilized. And it's actually from from our research, and the research of many different people. It seems that bacteria play an important role. Even though bacteria can decompose feces, they change the chemical conditions around within within certain substrates, and they can actually facilitate mineralization. So it seems kind of funny that we have fossilized species, probably because of the role of bacteria in helping to decompose them. And also, when you think about it, feces are basically bags of bacteria. So there are lots of bacteria that are there to help fossilize that.

Alex Re

That's amazing. You'd never think because bacteria are decomposers. So you would think that they would get rid of it. But that's, that's amazing. Yes. And is there a way of identifying which coprolites come from which organisms?

Karen Chin

Now that's a really good question. coprolite study is very challenging for a couple of reasons. One, first of all, you don't have a, a clear recurring shape like you have with bones or teeth, or shells, or leaves. feces are stretchy. And they,

they don't hold their shape. So when you find something that you think may be fossil feces, it doesn't have a a real often does not have a real recognizable shape, it can be deformed. And so the very first question, when we're studying feces is, is this actually fossil feces? Or is it just a rock shape? That has a physical shape? Or was it created some other way? So actually, that's the first question we ask. And we look at the contents, we look at the sometimes the shape, but not so much. And we look at the chemical composition and other factors to try to figure out if something is fossilized feces. Then the second question is the one you just asked, okay, if it's fossilized feces, who actually made it? And this is really challenging, I would have to say, in most cases, we do not know who produce the feces. In other words, we don't know who dung it. Okay, I just had to throw that in there. And that's because fecal shapes are so similar. Lots of different animals can produce the same shapes and sizes of feces. So we have to consider other characteristics that can tell us or at least give us clues about who might have produced the biggest clue is size. And that is because of you have a very large mass fecal mass. We know it couldn't have been produced by a mouse sized animal, right? Uh huh. On the other hand, if you have a really large animal like an elephant that produces feces, it can break apart so you can have a little chunk and that can be produced by a large animal. So I like working on dinosaur Wko for lice, because they're so large that we know that large animals produce them. And in most cases, the largest animals that lived in some of the sites that I investigate are at the time of when the rocks were deposited. We know those came from dinosaurs. So sizes important also contents, if you can recognize, chopped up bone, you know, it was produced by carnivora, chopped up leaves or chopped up shells, things like that, that will tell you, you know, what the animal was eating. And then finally, you look to see which animals left bones in the same sediments in which you find the coprolites, and you can then have a clue Wow, I have an herbivore coprolite. This giant and in the same sediments I found bones from large herbivorous duck billed dinosaurs. And so those are good candidates.

Alex Re

Just a side note that duck billed dinosaurs had really wide flattened mouse, and they could weigh 15,000 pounds. They lived around 85 million years ago.

Karen Chin

But unfortunately, because the feces, the fossilized feces are separate from the bones. We always have to say probably produced by something.

Alex Re

Yeah. And it seems so you have to take a lot of context into when you're looking at these coprolites. That's that's really interesting, actually. Yes. Yeah. And I was just about to ask, so bones can actually become fossilized inside of the coprolites.

Karen Chin

Actually, it's kind of surprising that coprolites can help preserve lots of things, not only bone, I mean, they're just a good vehicle for preserving things. Because, believe it or not, they can become mineralized very, very quickly. And so not only have we observed bones inside of coprolites, we've preserved we found things that are much less less sturdy than bones, we've actually found fossilized muscle tissue. In some coprolites, wow, we found people have found fossilized insects. And some people have even found fossilized parasites. And that's because if you can imagine that you have something soft, like okay, let's say we put an ant in a ice tray. And we freeze it very quickly, that ice will help protect that ant from decomposing very quickly. And that's the same kind of thing. If you have an ant in, in, in a fecal mass, and it's mineralized very quickly, like freezing it, then that protects it from being destroyed in other ways from the environment.

Alex Re

That's just crazy to think about. And so I'm sure coprolites have been able to tell you a lot about different organisms that lived during the times that you were studying it.

Karen Chin

Yes, that Cobra lights are kind of funny, because some specimens are so well preserved, they can tell you lots of things. Other specimens are not preserved, as well, but they can tell you other things. So what we learn from coprolites depends on how well they're preserved and what we see inside. Sometimes we learn about ancient animal diets. Sometimes we learn about how the material was preserved and how quickly it was preserved. And sometimes we get clues about what the ancient environment was like.

Alex Re

That's really amazing. And is there anything that you found in your research studying coprolites that really surprised you?

Karen Chin

Yes, there have been some things. I mentioned that we found muscle tissue. That was a real surprise. We were studying a fossilized terrano sore coprolite Okay, so this was not T Rex. It was an older relative of T Rex, but it was still a Toronto sore. And we found inside these weird preserved shapes. And they look they were the size and shape of muscle cells, which is muscle cells are basically meat, right? Yeah. And we found that inside if I thought, well, this can't be this has gone through the digestive tract of a Toronto Star. So we can't be seeing fossilized meat. But the more we studied it, we did chemical analyses and scanning electron microscopy, and other analyses. And the best interpretation is, we really did have fossilized muscle tissues, we, the morphology we had ma myofibrillar striations, which are very much like skeletal muscle tissue you see in our bodies or in other animals bodies. So the fact that that could preserve so quickly, was amazing. And it told us two things. One, that the meat wasn't totally digested when it went through the Toronto SARS digestive tract. And actually, that makes sense, because after I started working on this, I found that people have looked at dog feces and have found undigested muscle tissue and dog feces. And you figure a dog has a skull, that's maybe you know, if it's a very large dog, maybe 10 inches long, but a ton of so had a scholar was probably three feet long, and they couldn't chew. So they would gulp. And if they had rapid transit of the of the food through their digestive tract, it would not necessarily be exposed to digestive juices. So not only did it go through quickly, and it wasn't dissolved by digestive juices, but then it was mineralized really, really fast before the bacteria could decompose everything. And we have evidence for that happening to me because some people have taken modern shrimp, dead shrimp, and they buried them. And they have documented mineralization of the muscle tissue of the shrimp within weeks.

Alex Re

Really Wow. It's amazing. So in this case, we knew right well, I mean, we could presume from the shape of Toronto sore teeth that they were meat eaters. But in this particular case, what this coprolite told us more about was the process of digestion, the processes of digestion, and fossilization. So that was that was really a fun study. And then another study we did is where we found a cultural light from a very large herbivorous dinosaur also had chopped up pieces of crustacean in it. We don't know what kind of crustacean because we only saw bits and pieces of the exoskeleton, but maybe something like a crab. So it was amazing to think that some herbivorous dinosaurs actually also ingested crustaceans. I can't even imagine how cool that must have been to figure that out for the first time.

Karen Chin

It was, it was tons of fun. Yeah, that's what I like studying coprolites, because we never know what we're going to find.

Alex Re

That's so great. And you also do research into just ecosystems during the Mesozoic era, which is like the era of the dinosaurs. So were there any differences in climate and composition of the ecosystems between then and now?

Karen Chin

Well, in the Mesozoic, it was a greenhouse environment. So that means that we had no ice at the poles. The whole planet was warmer, although the distribution of warmth, people are still trying to understand that. So definitely, it was a warmer environment was a it was a it was, the climate was different.

Alex Re

One of the reasons why it was so warm was because there was a lot of carbon dioxide in the atmosphere, which traps in a bunch of heat. Carbon dioxide is also one of the main things causing climate change today. But

Karen Chin

probably some of the, in addition to that the most important differences between the Mesozoic ecosystems and our ecosystems was that they were just different organisms. You know, we had the, the huge non avian dinosaurs, like like duck billed dinosaurs and Tyrannosaurs. And then we had other smaller organisms that we just don't have today. And that would those interactions with each other and with the ecosystems would make those ancient ecosystems significantly different than they are today.

Alex Re

Absolutely, and it I would have have loved to go back and see all that and see all these differences? And I'm sure like in your work, you're just picturing that all the time probably.

Karen Chin

Yes, I wish, oh, we often just wish we had one of those, you know, like Mesozoic cam, recording things. So we could really see if all of our, our, our hypotheses about what these animals looked like and how they interacted with the environment if if they were true or not.

Alex Re

Yeah, definitely. And you also mentioned something about how it was a much warmer climate back then. So how, how were you able to figure stuff like that out? What kind of tools do you use? Because it happened so long ago?

Karen Chin

Well, right. There, a lot of people do paleoclimatic studies, and they look at different kinds of, of what we call paleo climate proxies, for example, sometimes you can look at the relative percentages of teeth in leaves. In modern environments, that gives you an idea of the temperature. Or you can look at the stable isotopes of certain microfossils. Like for M and ifrah. For M and F ra are tiny, single celled organisms that have shells. And because of their shells, they show up well in the fossil record, which can also in modern environments, they indicate what the sea temperature was. And it's kind of interesting, because in most cases, people who study climate, ancient climates don't usually look at things like fossil feces, right. But in one of our studies, we actually were able to extract organic compounds, organic geochemical compounds called biomarkers from coprolites. And that is a really active field in terms of trying to reconstruct ancient temperatures and, and other or other aspects of ancient climates. And the critical thing is that people use this tool very often to look at sediments. So they will take sediments and make a sample extract biomarkers out of those and say, Well, this indicates that the temperature was probably around this, this warm. But when you're looking at stratified sediments, you don't know whether those sediments represent five years, 10 years, 1000 years. So you're kind of doing time averaging, you're averaging from a given period of time. What if we look at a coprolite fossil species, you know that those animals sampled ancient organisms, and if it didn't go, you know, it might have taken a while for the the food to make the transit through the gut, while we're talking probably about a maximum of a week, if not a day or an hour of sampling. So it was really a really interesting way to look at a more focused, paleoclimate estimate from simply looking at sediments.

Alex Re

So what you're saying is coprolites are basically holding up the entire field of paleontology.

Karen Chin

I wish I could. No, we can't say that. But what I what I would like to say is that oftentimes, when people think about fossils, they're mostly talking about skeletal fossils. And people don't pay as much as much attention to trace fossils. And trace fossils are fossils that give that provide evidence of organisms activity. So they include fossilized feces, also tracks and burrows. So you don't see the body fossils in these, but they show where organisms were doing things, and people often don't pay as much attention to those fossils. But those fossils are important to.

Alex Re

Yeah, they're so important because they can tell you a skeleton can't tell you what the animal was doing. But a Burro might be able to tell you how they lived. Exactly, exactly. Yeah. Yeah. And is there any way that you can use your knowledge of the Mesozoic era to help The organisms that are struggling today.

Karen Chin

Well, I'd say that when we study the fossil record, it tells us things about rates of evolution, rates of extinction and environmental change. So this, these, these studies give us perspectives on what is happening today. And one thing they do tell us is that evolution and extinction, these things are always happening. They've happened in the past, we've seen animals go extinct. We've seen animals. And I say, animals, organisms, I mean, organisms go extinct, and organisms evolve there. So it's always going on. But the issue is that this is happening generally over long periods of time. And today, we have changed help to change the climate so rapidly, that evolution can't keep up with extinction. And that's why we are in another anthropogenic mass extinction today. So I think what studying the fossil record can tell us is it just gives us perspective on what is happening today.

Alex Re

Yeah, absolutely. And, like you were saying those extinction events happened over a long period of time, but this is a rapid amount of change that the world's not really ready for. Right, right. Exactly. Definitely. And this is going to be my last question, but how can the average person support your research and the study of paleontology in general?

Karen Chin

Okay, I will give. I will give two answers to that. I think, if we speak, if we're talking about paleontology, a very practical thing is if people are hiking around and they see fossils, the best thing to do is not to collect them, because we get lots of information from the context of the fossils, what sediments they're found in what you know, the position they're found in. But if they see something they should, it would really help us paleontologists if they would report it, or take a picture and send us a picture. But from a more global perspective, I would encourage people to just keep learning about science, about how science is done, and how we gather evidence to make our best interpretations to try and figure out how the the natural world works. Because I think understanding how science works is how everyday people can help support science and help us all work toward understanding and making this a better world.

Alex Re

I completely agree. I've said this on so many of my episodes, but I feel like education is the key to really saving the world and helping science in general. So thank you for that. And thank you so much for coming on. Yeah, I completely agree with you. And I want to thank you again for inviting me. Wow, who knew that dinosaur poop could tell us so much about ancient ecosystems and the animals that live there? I don't know about you. But I was completely shocked when I found out the dinosaur feces could even become fossilized. Kiran taught me so much about this underappreciated field of paleontology, and how we can relate it to the present day. If you want to learn more about paleontology, you should definitely go check out the paleontological society. Thank you so much for coming on this adventure with me as we explored the world of coprolites. You can find the sources that we use for this podcast and links to organizations that we reference at on wildlife.org. You can also email us with any questions at on wildlife. dot podcast@gmail.com and you can follow us on Instagram at en underscore wildlife and on tik tok at on wildlife. Don't forget to tune in next Wednesday for another awesome episode. And that's on wildlife.

Jess Avellino

You've been listening to on wildlife with Alex re brought to you every Wednesday.

Transcribed by https://otter.ai