Video
Dig Up! The Latest Research at Agate: 2024: Mattison Shreero
Transcript
Audio Description #1
Title slide with background landscape image of four-legged animals among scattered tall trees and a river. This is the background image for several future slides. Text: A Tiny Deer With Big Implications: A New Genus (Santuccimeryx) from Badlands National Park Helps Bridge the Gap Between Oligocene and Miocene Leptomerycidae (Mammalia, Artiodactyla) by Madison Shreero, Ed Welsh, Katherine Marriott, and Donald Prothero.
Slide #1
Hi everyone. Thanks for tuning in today to celebrate International Women and Girls in Science Day. I feel so honored to be speaking at this event and I just want to say a huge thank you up front to Tera Lynn Gray at Agate Fossil Beds for asking me to present my research. I'm also super excited to get to tell all of you about a neat little never-before seen fossil deer skull from Badlands National Park and discuss with you its implications on the evolutionary relationships of the Leptomerycids in general. Now, if you aren't familiar with Leptomerycids, don't panic. Not many people are and I'm going to cover all the basics. But first I'll tell you a little bit about my background and about what being a female scientist means to me.
Audio Description #2
Mattison talks from a lower section of the screen on each slide. She's a white female with light brown, wavy, shoulder length hair with bangs and glasses. A picture fills the screen of her and another person, both NPS uniforms, looking down at the texture dirt hills where they walk.
Slide #2
So hi, I'm Mattison. I studied Geology at Carlton College and I'm currently a park ranger at Badlands National Park. And about uh nine-eight- or nine months ago my colleague and co-author Ed Welsh and I decided to give a crap about tiny extinct deer from the Oligocene because we're well, we're huge nerds.
Audio Description #3
Left: headshot of small girl in braids and a pink bathing suit. Right: Mattison in an NPS uniform. Center text: When I grow up, I think it would be fun to be a geologist and a paleontologist because I think it would be fun to find rocks and dinosaur bones.
Slide #3
But to me, being a female scientist means a lot of different things. First, it means fulfilling a literal lifelong dream. This little girl in the top left corner here had her mom write this on a worksheet when she was in kindergarten. Back then she didn't know that being a park ranger means you get to do geology, paleontology, and so much more. But she is very glad she figured it out.
Audio Description #4
Three vertical panels fill the screen. First Mattison scratches a tool on a small bone at a table while a young girl watches. Second, screenshot of an Instagram account titled Geosplore with several pictures of Mattison. Third, screenshot of Mattison pointing to the title "Geology of Badlands National Park in 3 minutes or Less" with Instagram comments below. Then, five pictures of Mattison standing in fun poses with people of different genders and ethnicities.
Slides #4 & 5
And now being a female ranger and scientist I have the opportunity to be a role model for girls who are into science. I get to show them that there are jobs out there for them and that if I can achieve my goal of becoming a scientist, then they can too. I love this photo here on the left. One day while I was doing fossil prep at work, this this little girl walked up to me. And she stood there and watched what I was doing and talked to me for over an hour about fossils and about how she wants to be a paleontologist. It's because of interactions like this that it's become a goal of mine to foster accessibility of geologic and palaeontologic information and to increase awareness that jobs like this actually exist as a career path. And that specific goal has actually led me to social media, believe it or not, because right now it's the best and most accessible way to get information like this out there. Plus, I get to make fun little videos like explaining the geology of Badlands in less than three minutes. And even though social media is not something I ever thought I would be comfortable with doing, it can be incredibly fulfilling just like talking to the girls who come into the visitor center wanting to be scientists.
I promise I'll get to my research in just a sec, but being a female scientist also means being a part of the scientific community. Now, I've been super lucky to be a part of quite a few inclusive and uplifting groups and I quite simply would not be where I am today without their support. But this is certainly not always the case. Being a female scientist also means that frequently you're the only woman in the room; you get talked over; you're more easily dismissed; and it can certainly mean a lot of imposter syndrome (and that's to put it all very very lightly). Being a female in the geosciences specifically means existing in a space where most of the research and higher paying jobs are given to men even though most of the higher degrees in geology nowadays are awarded to women. So, before I dive into my research, I just want to challenge all of you out there to be a little more conscious going forward of the ongoing gender disparity in the sciences and to help us all work to correct it to make the sciences more inclusive because having more diverse voices contributing to science will ensure that better science gets done. It's as simple as that.
Audio Description #5
Mattison reads a list titled, "Three main takeaways." Then, title: Intro to Leptomerycidae. Followed by nine linked sub-orders in descending order. First, Mammal; then Artiodactyl (even-toed hoofed mammals); then Leptomercycidae (small, hornless, two-toed deer-like ruminants); then Pseudoparablastomeryx; then Leptomeryx. Geographic range: throughout Western Interior from Saskatchewan to Mexico. Temporal range: about 46 to 13 million years ago. One of the most common fossil finds in the White River Badlands.
Slides #6 & 7
All right, let's dive into the research. Then starting with the main points and conclusions we found so you guys kind of have an idea of what to expect up front. Most, most importantly we have the first ever skull of this little Oligocene deer called Leptomerycidae ellisae. And prior to the discovery of this skull, this species was only known about from jaw fragments. Second, as we studied the specimen in detail and compared it to the other species of Leptomercyidae out there, we began to realize that it displays traits from two different genera. And considering this combo of traits, I'm going to argue, and subsequently convince you of course, that Leptomerycidae ellisae should be reclassified into a new intermediate genus.
Y'all remember learning the whole taxonomic rank thing right? Like Kingdom, Phylom, Class, Order, etc. Well, the Leptomerycidae is an extinct family of small hornless deer-like ruminants. We're talking tiny, like between 3 to 8 pounds. and the Leptomerycidae contains several genera. But today we're going to be focusing on just two: Pseudoparablastomeryx, the genus with the best name ever, and Leptomerycidae ellisae. And these adorable little suckers come in quite a few varieties, or species if you want to get scientific about it. But we're only going to talk about species from the Northern Great Plains that have produced skull material. So that leaves us with Leptomerycidae evansi, Leptomerycidae ellisae (that's our guy), and Pseudoparablastomeryx scotti. And considering we're at Agate Fossil Beds, we just have to talk about Leptomerycidae agatensis.
Audio Description #6
Two columns of animal molars. Left is molar from Eocene, or Chadronian, labeled Leptomeryx speciosus. Three tan to off-white oval sections of a specimen with an upper layer one-third the size of the attached lower layer. The top layer is rounded and smooth. Right is molar from Oligocene, or Orellan, labeled Leptomeryx evansi. Same shaped specimen as former, but darker brown around edges and the top layer is jagged.
Slide #8
As it stands now, all of the different Leptomeryx species are classified based on differences in the lower molars. So, let's take a look at Leptomeryx speciosus versus Leptomeryx evansi. Both species have the same basic layout to their teeth, but Leptomeryx evansi has this diagnostic little fold in the enamel called the Paleomix fold and then the enamel itself is wrinkled rather than smooth. And this example right here shows us exactly why it's important to study these guys. They're extremely useful in biostratigraphy, which is basically just using the presence of different fossils in different layers of rock to tell how old that rock is. So our speciosus evansi examples here actually marks the boundary between two geologic epoch: the Eocene and the Oligocene.
Audio Description #7
Slide titled, "New discovery." Football-shaped head from right, left, and top perspectives. A large circular indentation is on each side of the skull where the eyes would be. Dark brown to black teeth with the jaw glued together by sediment of the same color as the skull. Then, Mattison points to a skull the size of a toddler's fist mounted below a photo of a tiny spotted deer.
Slides #9 & 10
Alright. Now that we've got some background information, without further ado, here is the skull! It was found in 2016 by a Badlands intern and it is beautifully intact, missing only the praxial and it retains those associated jaws. Naturally, the original identification of Leptomerycidae ellisae for this specimen was based on traits from the lower teeth, since nobody had ever seen a skull before this one. And this never-before-seen skull is now on display at the Badlands fossil preparation lab, if you ever want to come check it out in person.
And here's me and my co-author Ed pointing at it. We're very proud of our little guy.
Audio Description #8
Maps of Badlands National Park and Agate Fossil Beds National Monument overlaid on a topographic map of South Dakota and Nebraska.
Slides #11 & 12
Now, Badlands National Park, for those who aren't familiar, is located in the southwest corner of South Dakota. We're that little white blob on the map. Yeah, we can be seen from space. So, we're kind of a big deal. And if we take a look at our park map the Leptomerycidae ellisae skull came from the Cedar Pass area which is on the Eastern side of the park.
Now, Agate Fossil Beds National Monument, for those of you who aren't currently standing in the visitor center, is located in the northwest corner of Nebraska. So, Agate and Badlands aren't actually that far apart from each other in space. I think it's about a 3-hour 45 minute drive. But we're also not that far apart from each other in geologic time.
Audio Description #9
Graph of a horizontal geologic time scale with a color overlay between the middle of the Eocene and Oligocene for Badlands and the early section of the Miocene for Agate. All the Leptomeryx species lie within the Badlands column, except for L. agatenis in the Agate column.
Slide #13
Badlands covers a stretch of time from about 37 to 28 million years ago, while Agate covers 23 to 19 million years ago. And really, what's 6 million years between friends? And on top of this, both Agate and Badlands are characterized by sedimentary rocks that are host to rich assemblages of mammal fossils. And so in the background here you can see all of those different Leptomeryx species I mentioned earlier and how they overlap with Badlands and Agate in time. This family tree also shows how past researchers believe the Leptomeryx ol.. are related to each other. But trust me when I say paleontologists have been very confused about the evolutionary relationships of these guys for a long time. And honestly the skull we have might only confuse things more. Whew!
Audio Description #10
Arrow highlights a horizontal section of a jagged cliffside that stretches the width of the cliff about one quarter of the way from its top. Then, three overhead views of shiny dark or light brown teeth in rows of seven embedded into a jaw. Smile-shaped indentations have different depths across each tooth's top. Moving arrows indicate the molar section Mattison discusses.
Slides #14 & 15
The ellisae specimen I'm studying is from the Brulle formation at Badlands. More specifically, the skull came from a rock layer known as Unit 8, which has been dated to about 32 million years ago.
Now that we've got some context, I'm going to compare the anatomy of Leptomerycidae ellisae to the anatomy of the only other Leptomeryx known for skull material, Leptomercidae evansi and Pseudoparablastomeryx scotii. And I'm going to prove two things to you. First that Leptomercidae ellisae is different enough from the other Leptomeryx that it should be repositioned into a new genus and second that defining species of Leptomeryx based on only lower teeth is just a flawed practice in general. Oh, and we're going to keep a running tally to see who's more similar to our specimen, just so we can keep track. But right off the bat, you can see that uh as far as lower molars go, all three of these species are pretty similar. Now, if we get specific Leptomerycidae ellisae and Pseudoparablastomeryx scotti are both missing that Paleor fold, whereas this trait is, of course, diagnostic in Leptomeryx evansi. In addition, Leptomerycidae ellisae and Pseudoparablastomeryx scotti have smooth enamel. Whereas Leptomeryx evansi is highly crenulated. But the M3 molar is very reduced in P. scotti when compared to our other two Leptomeryx species and this trait is considered to be indicative of evolutionary relationships, so it's extra important. So this round is going to be a tie.
Audio Description #11
Three overhead views of shiny, light brown molars, same as previous photo except teeth are paired together, have much wider indentations in their tops, and the heights gradually decrease on our right end.
Slides #16
Moving on to the upper molars, again you can see that all three are pretty similar. But the shape of the third premolar in L. ellisae is much closer to that of L. evansi, whereas the third premolar in P. scotti is expanded, creating a sort of basin. So it looks like this round goes to L. evansi.
Audio Description #12
Three football- shaped skulls viewed from their top surface. The cranium length of evansi measures 44.7 mm, L. ellisae is 36.4 mm, and P. scotii is 38.3 mm. The width between the ears varies with evansi being its smallest and scotii being the greatest.
Slide #13
Alright, here's where things really get wild. um So, in the cranium, the sagittal crust is much longer in Leptomeryx evansi than in the other two. And L. evansi has decreased temporal crests that open at a smaller angle. And, last, the length of the cranium itself is comparable between Leptomeryx ellisae and Pseudoparablastomeryx scotti, but it is between 6 and 8 millimeters longer in L evansi, which may not seem like a huge difference to us but in such a tiny animal that represents a pretty large ratio of the total skull length. And with that P. scotti wins this round. Which, of course, brings us back to a tie. Now, that was a lot of differences in a short amount of time. And trust me when I say there are many, many, more detailed observations that are going to go into our paper. We just didn't have time for them today. But to sum up, the main thing to note is that the teeth on this thing are pretty similar to Leptomerycidae evansi, while the skull is pretty similar to Pseudoparablastomeryx. So with that quick lesson in comparative anatomy, I hope I've thoroughly, thoroughly proven to you that with the intermediate nature of its traits, Leptomerycidae ellisae just cannot be confidently placed in either the genus Leptomeryx or the genus Pseudoparablastomeryx.
Audio Description #13
Slide titled, "New Genus." A toxomic list reads, Class Mammilia; Order Artiodactyla; Family Leptomerycidae; Genus Santuccimeryx; and Species Santuccimeryx ellisae. A photo of a white male with a close-shaved beard and mustache wears The NPS uniform and ionic flat hat. It sits next to information about him read by Mattison.
Slide #14
So, we're elevating Leptomerycidae ellisae to a new genus. And in terms of a name, we could not think of anyone more deserving than Vince Santucci, our friend and colleague, who is the head of the Geologic Resources Division for the National Park Service and a huge supporter of the Paleontology program at Badlands. So, we're naming the genus Santuccimeryx in honor of him.
Audio Description #14
Overhead view of a shiny, light brown molar of seven paired teeth embedded in a jaw with number 81505 written on it in black marker labeled Leptomeryx agatensis. It sits next to a list of information read by Mattison. Then, question marks sit on top of six pictured skulls in a family tree starting from the same genus. The three pictured skulls discussed in this presentation display with a dotted line and without a question mark. Finally, a list of conclusions read by Mattison.
Slides #15, 16, & 17
And now for the question I know you've all been asking, what about Leptomeryx agatensis? This species was named in 1922 based off this specimen shown here. It is, of course, named after Agate, Nebraska and it comes from the same rock layer as the fossil quarries at Agate Fossil Beds National Monument. And it is temporally intermediate between Leptomeryx and Pseudoparablastomeryx, which would theoretically make it a good species to look into when considering where to place our specimen. But sadly, this species has already been synonymized with Leptomeryx obliquidens, which we know from other specimens is vastly different than our Leptomerycidae ellisae. That being said, the combining of these two species, Leptomeryx obliquidens and Leptomeryx ellisae that was done on the basis of dental characters alone. And if we think back to what we literally just learned, our specimen was also considered part of the Leptomeryx genus when we all we had was teeth to go off of. But now that we have seen a skull, it very clearly does not belong in Leptomeryx. So who knows, maybe Leptomeryx agatensis could be its own species or even its own genus after all. So right now, I need somebody who's watching this from the Agate Visitor Center to go out there and find me a skull. Okay? Sounds good.
And if we take a look back at that initial family tree again, basically we only have three skulls to go on. So it's really hard, if not impossible to be confident about who's related to who. But with the characteristics we do have, it's like that Leptomeryx ellisae either split off from Leptomeryx evansi or Leptomeryx speciosis. The truth of the matter though, is that the evolutionary relationships of the Leptomeryx will remain uncertain until additional specimens can be collected that provide unambiguous characters to clarify the relationships between these genera. Basically in conclusion, we need more skulls!
And when those additional skulls show up, it's highly likely that the entire Leptomeryx family will need reevaluation. But for now, we will publish the info we have and announce our new genus Santuccimeryx in a paper in the South Dakota Academy of Sciences Journal. So, keep an eye out for that, should be coming out sometime this summer. Oh, and Leptomeryx agatensis probably shouldn't be resurrected just quite yet, but you know a girl can dream.
Audio Description #15
Slide title, "Acknowledgements." List: Tera Lynn Gray and Agate Fossil Bed's National Monument for hosting the event; Ellen Stark, Mary Carpenter, and Alex Carrier at Badlands National Park; Badlands National History Association; Nate Fox and Darren Pagnac at South Dakota School of Mines and Technology Museum of Geology; Judy Galkin and Meng Jin at the American Museum of Natural History; Tiffany Leone, Badlands GIP Intern 2016 who found the S. ellisae skull. And that about sums us up.
Slide #18
So, thank you all so much for listening today and learning about tiny little Oligocene deer with me. And I also just want to extend a huge, huge thank you to all of these amazing people. My co-authors and I would not have been able to do it without you. Thank you so much!
End
Description
It's International Day of Women & Girls in Science! Mattison is one of four female paleontologists who virtually shared her latest paleontological research at Agate Fossil Beds and Badlands National Park. She studies the Leptomerycids, ancient deer. 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=C1rGoR5qUPA
Duration
18 minutes, 22 seconds
Date Created
02/12/2024
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