Video
Dig Up! The Latest Research at Agate: 2024: Kristin Watmore
Transcript
Audio Description #1
A woman wears a large straw hat and shows us a fossil fragment in one of her hands. Title Kristin Watmore, Agate Fossil Beds, National Women and Science Day, February 11th 2024. Kristin speaks from a small corner of each screen. She's a white woman with long light brown hair pulled back with a headband. Then, four photos show Kristen holding a fossil; standing by a large research poster; sitting outside with her arm inside a hollow area of a cliff; and standing with other people indoors.
Slide #1 & #2
Hi everyone. My name is Kristin Watmore. I'm a grad student at Cal Poly Pomona in Southern California and I'm studying Vertebrate Paleontology. Thank you to Agate Fossil Beds for having me speak today. So, just for a little bit of background about myself and how I got here, so I was like a lot of kids and paleontologists was the first job that I ever wanted. And I had always been really interested in the natural and earth sciences, but for a while I didn't quite know that paleontology was really a real job that I could actually have. um So, with that, I did my undergrad in Biology and it wasn't until my junior year of my uh Biology degree, that I met my current adviser, Dr. Donald Prothero, and he basically showed me that paleontology it's a career that is possible. um And he took me on as a research student, and has showed me the wonders of the field since.
um And so some of these images here uh show you what I've gotten to do over the past couple years of getting into research. um I've gotten to collect data from a bunch of different museum collections. um I presented my research at conferences. um and I've gotten a chance to do field work as well. um And then the image on the very far right is me with uh my adviser Dr Prothero, as well as, a couple of my research peers. I have a few more of them that aren't pictured as well. um And it's, it's interesting; it's been a really great experience um having most of my research peers be other females um that are really supportive of each other um and it's just been a true gift to learn and work alongside of them.
Audio Description #2
Three lanky deer-like animals stand in front of a pink background titled, "The Stenomyline Camels. Research presented by Kristin Watmore in collaboration with Dr. Donald Prothero."
Slide #3
So with that, I'm going to tell you now about some of the research I've been doing um in paleo. um And so the group that I'm going to be talking about today that I've been studying um are called the Stenomylus camels. um So, this is going to be presenting research uh that I'm currently working on, in collaboration with my research adviser Dr. Donald Prothero.
Audio Description #3
Eight illustrations of different camels, some with back humps and some without, line up under a reverse image of the seven continents with the Americans on the right and Africa and Europe on the left. Symbols show where each species started. an arrow originates in North America and expands out to the other continents.
Slide #4
So, it's understandable, if when you saw the picture on the last slide, that those did not align with the first thing that came to mind when you thought of a camel. um The camels that we're familiar with today are um like the Batree and the Dromedary from the Middle East and Africa are large animals and they have humps. uh There's also um other camelids that are living today in South America like guanacos, vacunas, llamas, and alpacas. And those are all within the group of camelids. um But millions of years ago, uh camels actually evolved in North America, and then they diversified there, and over time, migrated into these other places um and were only left with the skeletal remnants of the presence of these camels in North America.
Audio Description #4
Geologic time scale from Eocene to Plistocene that list vertically. A single line follows the scale with the names of various camels listed as leaves off the main line. Stenomylus is the sixth leaf from the bottom between the Eocene and Miocene. Then, silhouette of camel with two humps and long droopy neck appears, and quickly gets crossed out.
Slide #5
So today, I'm just going to be talking about uh one of these groups of ancient camelids, which I'll box here, they are called the Stenomylus. And as you can see, they appear relatively early on in the camelid ancestry, appearing uh in the Eocene and spanning all the way through the middle Miocene. And you can also note from this tree here, that there's a lot of morphological differences, um variability, seen in uh early camelids that really doesn't look like the camels that we think of today. um And even more interestingly, we always think of camels having humps, um but the majority of camelids living today actually don't have humps. So, we don't assume that um the camel group that I'm talking about today or other um similar early camelids had humps either. So, we're picturing uh quite different type of animal.
Audio Description #5
Kristin reads from a list of four bullet points under the title, What is a Stenomylus?
Slide #6
So what is a Stenomylus then? So, we usually call Stenomylines the gazelle-like camels and this isn't because they're related to gazelle in any way. It's just the closest um kind of description we can give based on um their morphology. It's because they're pretty, they were pretty lightly built um animals with long skinny legs. And then they're also, really this group is known for their evolution of extreme hypsodonty. uh And hypsodonty refers to high crown teeth. So, this is something that I've done research in on in the past and I did, I presented on this last year. um It's an, it's an interesting part of their evolutionary history. And so like I mentioned they are a North American group uh spanning the Eocene through the Miocene. And then today, I'm also going to get more specific and look at four genre within uh the tribe Stenomylinene which is within the overarching group of the Stenomylines. um And there's four genre in that group. uh Stenomylus, which we'll be talking about specifically today, uh but there's also Blickomylus, Rakaomylus, and Wyomylus.
Audio Description #6
Geologic time scale of the Cenezoic from 66 million years ago to the 1950s displays horizontally. A box highlights the mid-Oligocene to the mid-Eocene. Three photos also display on the screen; each showing a lanky deer-like animal with very narrow body features. Kristin crouches next to one displayed skeleton where her head is taller than the animal's back.
Slide #7
And then just to give you a little more visual representation of, of this group, um these are examples of Stenomylines uh in skeletal mounts in museums. And then reconstructions of what they might have looked like um in life. As well as down on the bottom right, is me uh for scale measuring the limb bones of, of a Stenomylus. um And it just shows you how they're kind of like large dog size. They're not, they were not large animals like we think of camels today.
Audio Description #7
Kristin stands next to a research poster indoors with a name badge hung around her neck. Poster titled, "Dietary Modifications of Teeth and Early Miocene Stenomyline Camels." She reads from a list of three bullet points titled, "Conclusions."
Slide #8
So, then briefly just before I get into uh the new research that I'm working on, in case you watched uh my presentation uh last year for Agate, I talked about a project I was working on uh with a few of the genre in the Stenomylines uh in terms of their hypsodonty, or how high crowned their teeth were. And now this uh work has been published, as well as presented at GSA and SVP. So, some of the conclusions that I ended up uh making for this research was that the Stenomylines do appear to be one of the most hypsodont mammals of their time, uh which is striking because it means they were more hypsodont than the horses that they lived alongside like Marhippus. um And then genre like Blickomylus uh were particularly uh more hypsodont and they were potentially specialists in arid environments with really gritty vegetation.
Audio Description #8
A group of Stenomylus skeletons displayed indoors in various positions, including lying on the ground. Text, List of described species: S grasselis, S. graus, S hitchcocki, S. keelinemensis, S. taylori, and S. tuberamenti. Then, black Ink writing appears on four jaw bones with long tubular embedded teeth. Kristin reads from a list of eight bullet points. Finally, Kristen reads from a list of three bullet points titled, The Taxanomic Problem." Then she reads two main questions on the screen.
Slide #9, #10, #11, #12
So now, switching gears a little bit from my old project. Now, I'm going to be talking about my current research project I'm working on uh which is about Stenomylus Systematics. So now we're zooming in on just one genus within the Stenomylines, which is the namesake genus Stenomylus. um And the goal of this research is I'm looking to evaluate uh the validity of the taxonomy that exists for this genus. And there's currently uh six described species and I'm going to be focusing on two of them: uh gracilis and hitchcocki, um which I'll go into more depth on future slides.
So, what does the literature say about the Stenomylus systematics? So, S. gracilis; so, Stenomylus gracilias is uh the type species for the genus and is found in the lower Harrison beds. And some of the defining characters of this species in particular are said to be its larger size, smaller premolars and taller molars compared to the other species in the group. um Then there's S. hitchcocki which is found uh in the Stenomylus quarry near Agate. So, then if you're comparing the two, um S. gracilis actually just comes from one layer below uh Agate quarry, uh the beds that the S. hitchcocki were actually found in. um And then also I'll mention another one of them uh because I have an image for it, S. keelinensis, um which is defined on a single specimen with a larger canine. So, you can just kind of see um all of them look uh similar at first glance. um But that's why we have to do systematics to kind of see uh are they actually different or are they the same.
So, what's the taxonomic problem here that I'm actually trying to investigate? So, this is actually quite a common um issue in paleontology. So, it's not unique to the Stenomylus, but this is a good example of a group to do this kind of research on. So, the issue is oversplitting of this genus into more species than were likely to be biologically represented in nature. um So, previous uh studies had not really done statistical analyses to actually support whether one species would different was different from another other species. um Also, it's notable that some species are based on a single specimen which is not typically the most robust way to do systematics um today. um And then also large samples of various Stenomylus species are found uh from the same locality. So, we have to keep these things in mind when we're saying one thing is different than the other, um especially if they were living uh in the same place at the same time and um are not abundantly different from each other.
My main questions for this research are: One, does the data support S. gracilis and S. hitchcocki as being distinct species? And then two, um since variability is a natural part of living populations is as the talk, taxonomy stands now, is this variability accounted for in the um species designations that have been given? um And this is important to think about um the idea of intraspecific variation, meaning uh variation within one species um because this is quite a common phenomenon with things like sexual dimorphism which will make a female and a male different from each other. um It might be obvious or it might be more subtle, but these differences should be accounted for. And then also just naturally some individuals are smaller or larger than others. This wouldn't um by itself mean that we separate them into different species.
Audio Description #9
Kristin reads from a list of 5 bullet points titled, "Methods." Three jaw bones with long tubular, embedded teeth have black ink written on them. Caption: Holotype of S gracilis refers to the jaw which is a short length and curved similar to a boomerang. Caption: Specimen of S. hitchcocki refers to the jaw which is a long length and curves only slightly at its back end.
Slide #12
The methods that we're using to conduct this research um include a standardized uh way of um measuring kind of a proxy for size uh amongst these species. So we measure the premolar and molar tooth row lengths in both the uppers and the lowers. um And then we're also measuring the canine width and height for um purposes of sexual dimorphism. We're also noting any consistent morphological differences that we see between species or that's been referenced in the literature for us to look out for. And then we're cross referencing uh what we see with that literature. um And then I also want to mention that um this kind of statistical analysis typically involves uh looking at species that have has a good amount a good sample size to look at. So, um in this case, S. gracilis and S. hitchcocki do provide a large enough sample size to do these kind of statistics.
Audio Description #10
Scatter plot graph with P2 through P4 across the bottom and M1 through M3 along the side. Different color dots indicate S cressipes, S. graciles or S. hitchcocki. Green symbolizing hitchcocki is the most abundant and is spread all over the graph.
Slide #13
So, these next few slides are going to be showing you similar plots. um Just to orient you, the x-axis is going to be uh the premolar row length, and the y- axis is the molar row length. And then each color is identifying a different species that we've taken this uh these measurements of, and then plotting them together. um So, on this plot, this is showing the, this plot of the upper tooth row lengths, and what we can see from this just visually looking at it is that there don't really seem to be any visual clusters. um If there was really a clear cluster, that would be supportive of the, that oh this this species is different than another species because they're not clustering um together in size categories. um And then we can run statistical tests on it, that I won't go too deeply into, um but the idea is that we can get values that show us if there is a significant difference between uh one species and another species. And then we can do further tests to see which uh group that is in. um And so from this, we're actually getting a P value that's showing us that there's not, uh there doesn't look to be a significant difference between species, which is supportive of the idea that maybe S. hitchcocki and S. gracilis should not have been split into separate groups.
Audio Description #11
Scatter plot graph with P2 through P4 across the bottom and M1 through M3 along the side. An additional species of S. keelinensis is added to the graph with only one plot point Of 20 plots, 11 are in the middle cluster of the graph.
Slide #14
And so this plot is showing uh similar measurements plotted together. But these are from the lower tooth row um and in this case we are getting a um significant P value, which means there could be a group in here that is significantly different uh than another, another species, um We already know that there is one species that is pretty confidently um different and earlier uh species than the others. So, it's likely that we're getting this uh signal from that um but a further test could confirm uh if this difference is significant between, between S. hitchcocki and S. gracilis, or if it's not.
Audio Description #12
Two scatter plot graphs with same structure as before. Left: graph caption: Premolar versus molar, upper tooth row lengths. MANOVA test. P value equals 0.39. Right: graph caption: Premolar versus molar, lower tooth row lengths. MANOVA test. P value equals 0.0082.
Slide #15
And these plots are showing basically the same thing that we saw in the last two. I just Incorporated measurements that we took from museum specimens that uh were not identified to species level. They were just labeled as Stenomylus. And then that just helps add to having a larger sample size um to do these statistics on.
Audio Description #13
Scatter plot graph with canine width across bottom and canine height along side. Of 13 plot points of four different species, six cluster in the top right corner and three cluster in the bottom right corner. Kristin reads from a list of four bullet points labeled, Next Steps.
Slide #16
So, as it looks preliminarily, um it appears that Stenomylus hitchcocki and Stenomylus gracilis may not actually uh be different species. We'll have to do uh more stats on, on this to confirm this. um As well as, next step of increasing our sample size uh to do this research. But that's how currently it is looking for these two species. um And then, we also want to address uh the potential sexual dimorphism uh in the canine tooth which uh is a part of that intraspecific variation that I mentioned earlier. um Here's just a simple plot showing uh canine measurements and we can just kind of see that for each species, there does seem to be a smaller group cluster and then a larger group cluster. um So like I said, we want to also perform more stat tests to decide which species actually are different from one another. And then we will retain, at the end of this, we will retain the valid species and then have to synonymize uh the species that don't have support.
Audio Description #14
Two photos next to a list of two implications. First, a small museum sign labels Stenomylus hitchcocki. And second, a page from a book labels Stenomylus. Highlighted yellow are the four species: hitchcocki, cressipes, keelinensis, gracilis.
Slide #17
So finally, it's important for me to finish with the implications that this kind of research can have uh for paleontology. So, if we conclude that there is no evidence to support a difference between the Stenomylus gracilis and Stenomylus hitchcocki species, then Stenomylus hitchcocki is no longer going to be a valid species, and that name will have to be synonymized into S. gracilus. um And this occurs because um the rules of, of nomenclature. S. gracilis got the name first. uh It was the first name species in 1906. um So, it has seniority over that second name S. hitchcocki from 1910. So, if there really is no difference, Stomylus hitchcocki is going to disappear um and we would be left with gracilis, as well as the other species, given that they have support as well. um So this means that uh textbooks, museums, paleo art labels, they would all need to be changed because Stenomylus hitchcocki is actually the same thing as Stenomylus gracilis, if this is what our uh findings support. um And this is just all connected to the idea that taxonomy is data in paleontology, and we need to have well supported taxonomy to give us an accurate indication of what species diversity was um in the past.
Audio Description #15
Stock image of a thick, short- haired camel with a droopy neck. A piece of grass sticks out of its narrow snout and mouth, which stares at us.
Slide #18
And so, with that, I want to thank you all for listening today and thank Agate Fossil Beds for having me. It's always great to be able to share my experience in paleo uh with other people, as well as what research I'm working on. So, I hope you learned something. And happy National Women in Scienc
Description
It's International Day of Women & Girls in Science! Kristin is one of four female paleontologists who virtually shared her latest paleontological research at Agate Fossil Beds and Badlands National Park. She studies the Stenomylus, an ancient camel. This video is captioned, audio described, and interpreted into ASL. Check out our YouTube Channel to read the questions & answers that occurred live during the program. https://www.youtube.com/watch?v=ctq_uaDMA9M
Duration
20 minutes, 6 seconds
Date Created
02/12/2024
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