3rd Palaeontological Virtual Congress

This year is the third iteration of an entirely online conference, Palaeontological Virtual Congress, open to abstract submissions from anyone studying paleontological sciences. A broadly accessible conference as the digital means provides increased access to scientific content. There is flexibility with file format, presenters can be visible on camera augmented by images and slides edited into the video, upload their slides without an overlaying audio, or walk through their slides while providing audio narrative. We asked Vicente Crespo, the main organizer, some questions about the concept and the history of the conference.

Who organized this event?

The Organizing Committee is formed by 9 people, with 3 professors (Evangelos Vlachos, Rosalía Guerrero-Arenas and Penélope Cruzádo-Caballero), 4 post-doctoral researchers (María Ríos, Francesc Gascó, Humberto G. Ferrón and me), and 2 pre-doc students (Fernando A. M. Arnal and José Luis Herráiz) from five different countries. In the past editions of the congress, it was expected there would be around 100 participants, and the final attendees were near 400. This year there was a total of 275 contributions presented, and I we will have around 600 participants, which at the moment are from 51 different registered countries.

What are the major changes in the upcoming event compared to the last installment?

Although we always try to keep a similar format, which is comfortable and easy for users, we also try to innovate in each edition and try to learn each time from the advice given by the participants. This is why this edition we have set new Discord channels, so that interaction between participants is more direct and easy plus we set a new website. But, and above all, in this edition we really wanted to make clear the purpose of this initiative which is to reach all, and include all, which meant setting a new Social Fund that allows participants from low and lower-middle income countries to get a registration free of charge.

Online conferences have gotten much more common as the COVID-19 crisis persists. Will this change how people perceive the PalaeoVC?

I hope it won’t change the way people see us! It is true that in these difficult times, typically face-to-face congresses have become virtual. Most of them have kept their in-person soul, that is, reduced to the same time period as their face-to-face versions and the conferences in real time, although I believe that in time, they will return to being in person. However, in the PVC, which was held before the pandemic, and is aimed at a more global audience, the congress lasts 15 days, and the presentations are not live, so you can enjoy them at any time of the day, and as many times as you want, with the freedom other type of events do not provide.

Will there be a 4th PalaeoVC?

Hopefully there will be a fourth edition, especially with the success in participation of this third edition. Our idea is to hold it every year and a half, so the next one should be in May 2023.

So hope you enjoy it and See you soon at the 3rd PVC… and at the 4th PVC!

To learn more about the Palaeontological Virtual Congress, follow them on Facebook at PalaeoVC, Instagram @palaeovc, and on Twitter @palaeovc!

Examining Cryolophosaurus: Shedding Light on a Little-Known and Important Jurassic Dinosaur

An enigmatic theropod Cryolophosaurus: Reviews and comments on its paleobiology

By: Changyu Yun

Summarized by Ohav Harris, a geology major at the University of South Florida and is currently a junior. He plans to pursue a doctorate degree in paleontology and become a paleo-educator in some capacity, either working in a museum or a university. In his free time, Ohav enjoys collecting Pokémon cards, reading manga, and fishing.

What data were used? The author, Yun, used many previously published peer reviewed papers to review and evaluate the ideas that exist regarding Cryolophosaurus’s evolutionary relationships, or phylogenetics. The only known fossil data for this dinosaur are hip fragments, various vertebrae, rib fragments, femurs, part of its foot, and the holotype (the fossil that the description of the genus/species is based on), which include the skull and neck vertebrae – all of which were found in Antarctica. The sparse remains of Cryolophosaurus make it difficult to make definitive statements of its relationship to other theropods (bipedal dinosaurs that are primarily carnivorous), though researchers are confident that it is a theropod. Yun includes an array of possibilities from various sources that attempt to answer the question of this dinosaur’s phylogeny and examines what fossil data of Cryolophosaurus there are to make comments on its ecology and biology.

Methods: Yun analyzes Cryolophosaurus’ anatomy and geographical placement, makes comparisons to better known dinosaurs, and references scientific papers that discuss this Cryolophosaurus to draw conclusions regarding its possible phylogeny, ecology, and biology. Certain features of this animal, like the shape of its skull, the structure of its feet, and the purpose of its skull crest, are discussed and used to support Yun’s claims of the nature of Cryolophosaurus.

Reconstruction of Cryolophosaurus by Daniel Goitom. The defining crest is boldly colored, so as to attract the attention of a mate. Cryolophosaurus’s primitive, needle-like feathers would have been an excellent source of thermal insulation in the Antarctic climate in which it lived.

Results: While the exact phylogeny of Cryolophosaurus is tricky, and not yet fully understood, there are a few things that can be said about it. The skull of Cryolophosaurus has features of tetanurans, dinosaurs that are more closely related to modern birds, like Allosaurus, and earlier, more primitive therapods like Ceratosaurus. Tetanurans and Ceratosaurus are closely related, but took different evolutionary paths. The tetanurans are made up of two groups, carnosaurs and coelurosaurs, which contain a majority of the most famous therapods like Allosaurus and Tyrannosaurus respectively, and all modern birds (descending from the coelurosaurs). Because Cryolophosaurus’ skull has both features of tetanurans and earlier theropods, it can be inferred that it is a transitional fossil that links the first theropods in the Jurassic and all subsequent therapods and modern birds. It is also likely that, based on its shared features between both theropod groups, Cryolophosaurus is an early tetanuran. This possibility is briefly discussed in the paper. It was also determined that Cryolophosaurus was an apex predator in its Antarctic environment, able to make swift movements and out-speed its prey to capture them. This is based on the animal’s astragalus (the bone in the foot between the shin and tarsals) and calcaneum (the bone just under the astragalus that forms the heel) being fused through ossification, or the growth of new bone material. Because dinosaurs walked on their tiptoes, this would not affect their stability as it would for humans. Additionally, those two bones are located right next to each other in dinosaur feet, which means that Cryolophosaurus only had one “ankle” bone where it would usually have had two. Taphonomic evidence (relating to the processes a body undergoes after death, including fossilization), supports the idea of Cryolophosaurus being an apex predator, as herbivore teeth have been found in its stomach. Sauropods, the long-necked dinosaurs, have also been found in the same formation as Cryolophosaurus, which could suggest they were also potential prey. Interestingly, the Cryolophosaurus holotype was found disarticulated with shed teeth nearby. These teeth are believed to have belonged to another Cryolophosaurus, suggesting that this dinosaur may have had cannibalistic tendencies. The characteristic crest of the dinosaur (Fig. 1) is believed to have been used as a display for attracting mates, with differences in bodily characteristics between males and females.

Why is this study important? Cryolophosaurus is an important dinosaur for theropod evolution because it is likely a transitional fossil connecting the earliest therapods to the tetanurans that came after. Understanding this dinosaur’s place in the phylogeny of theropods is important because it can elucidate various unknowns about their evolution. Cyrolophosaurus’ environment was also unique, being the only therapod yet discovered in Antarctica, which was a colder climate than what other dinosaurs in the Jurassic were living in. This provides a new perspective into dinosaur ecology, particularly through the lens of dinosaurs adapted for colder climates.

The big picture: Dinosaur paleontology is generally regarded by the public as being centered around the most popular Late-Cretaceous genera like Tyrannosaurus, Triceratops, and Velociraptor without much consideration for their ecology or even other dinosaurs from different periods. This study sheds light on one such lesser-known dinosaur, Cryolophosaurus, and states its importance to the phylogeny of theropod dinosaurs as well as its ecological role. Understanding the “niche” and lesser known dinosaurs is extremely important to the understanding of dinosaur paleontology, as those dinosaurs often provide much insight, not only into their evolution and development, but also to the unique nature and attributes of dinosaurs as a whole.

Citation: Yun, Changyu, 2020. An enigmatic theropod Cryolophosaurus: Reviews and comments on its paleobiology. VOLUMINA JURASSICA, 2019, XVII: 103–110

Reconstructing South Korea’s Cretaceous with the First Evidence of Crocodilian Tracks Found

First reports of Crocodylopodus from East Asia: implications for the paleoecology of the Lower Cretaceous

By: Martin G. Lockley, Jong Deock Lim, Hong Deock Park, Anthony Romilio Jae Sang Yoo, Ji Won Choi, Kyung Soo Kim, Yeongi Choi, Seung-Hyeop Kang, Dong Hee Kim, Tae Hyeong Kim.

Summarized by: Noel J. Hernandez G., a current geology senior undergraduat et at The University of South Florida. He plans to continue his education in paleontology by going to graduate school. He is hoping to eventually get his PhD in paleontology and become a professor that performs research throughout the world. He is also known as a video game enthusiast and enjoys science more than any person realistically should.

What data were used? The first samples of Crocodylopodus fossil footprints in the Cretaceous-age Jinju formation of South Korea, and previous samples of other kinds of crocodilian prints from the Mesozoic Era.

Methods: This study was conducted and made possible by many different organizations and study groups all working on the same project on the Jinju formation in South Korea. There were a multitude of samples gathered from four different dig sites, but this study focuses on the best-preserved samples. These samples were photographed using specialized 3D cameras and run through different software to create comprehensive elevation maps that could clearly show the indentations of the prints on the shale rock. Then, each visible print was studied and measured to identify possible the tracks that these animals made, this way, their walking patterns could be identified and matched with existing data to find the proper classification for them.

Results: There are many different kinds of prints that animals can leave behind as fossils. This could be due to different movement behaviors, different feeding methods, or even resting positions; we call fossils of these preserved behaviors, like these prints, ichnofossils. Crocodylopodus is one such type of footprint ichnofossil that was left behind by crocodile-like animals millions of years ago, though there are other kinds of common crocodile ichnofossils, such as Batrachopus and Hatcherichnus. In this study, these other common crocodile ichnofossils are used to compare these new samples of Crocodylopodus found with pre-existing data to try and understand what these tracks means for the organisms that produced them. The study finds that these prints are complete enough to reassemble the possible way that these animals walked. From this information, they found sufficient evidence to say that these crocodilians probably walked on land more than previously thought, unlike Hatcherichnus that demonstrate swimming. Crocodylopodus demonstrates walking in all of the samples found at these sites because of the types of sediments that they were imprinted on, representing shallow rivers and floodplains. Swimming tracks usually have small footprints with tail traces along with them, but Crocodylopodus does not show tail traces.

This changes the idea that most crocodilians in Eastern Asia during the Mesozoic were mostly aquatic animals, and this finding suggests that the trait of being aquatic or terrestrial primarily has been dependent on the kind of environments these animals lived in, as similar ichnofossils from different parts of the world show different habits in varying ecosystems.


Why is this study important? This study is part of a bigger ongoing study of a brand-new region of the world that has not been thoroughly studied for paleontology; specifically, the Jinju Formation is an area of South Korea that has not been heavily studied in the past. Many new species and recurrences of previously known species are coming up as more and more ichnofossils are uncovered. The more studies that are done on these samples, the closer we get to understanding how the paleoecology (i.e., how ancient animals interacted with each other and their environment) functioned there.

Slab with Crocodylopodus and other small mammal ichnofossil. A. Draw representation showing where each trace is located and the direction of the tracks. B. Low exposure picture of the actual fossil assemblage. C. Elevation imaging of the slab to show impression.

The big picture: These assemblages of trace fossils (ichnofossils) had not only the traces of crocodile-like animals, but they also had other kinds of trace fossils made by other organisms. There were many small animal prints and other kinds of reptile and amphibian prints as well, Crocodylopodus was only a part of the active biological community that existed in this area during the Cretaceous. Seeing how these crocodilians moved and lived among all of these other animals helps us understand the region better.

Citation: Martin G. Lockley, Jong Deock Lim, Hong Deock Park, Anthony Romilio, Jae Sang Yoo, Ji Won Choi, Kyung Soo Kim, Yeongi Choi, Seung-Hyeop Kang, Dong Hee Kim, Tae Hyeong Kim, 2020, First reports of Crocodylopodus from East Asia: implications for the paleoecology of the Lower Cretaceous, Cretaceous Research, Volume 111, 104441, ISSN 0195-6671, https://doi.org/10.1016/j.cretres.2020.104441

Patty Standring, PhD Student at University of Texas at Austin studying paleoceanography using benthic foraminifera

Hello! I am Patty, and I am a 2nd year PhD student at the University of Texas at Austin (UT). I am also an Air Force veteran. I worked as a Dari Linguist during my 10 years in the military before returning to school to get a bachelor’s degree at UT in geophysics.

Photo of me in front of my microscope at the Institute for Geophysics.

What research are you doing for your PhD? I am studying the paleoceanography of the Gulf of Mexico and the Caribbean during the Eocene and Oligocene epochs (~30-40 million years ago). I look for tiny fossil shells from organisms called foraminifera (forams for short) in deep-sea sediments, and then analyze the isotopes in the shells. I specifically study the forams that live on the seafloor, so they are referred to as benthic forams, whereas planktic forams float in the water column. Forams are single-celled organisms and build their calcite shells from elements in the seawater, essentially recording what seawater conditions were like when they were alive and giving us information about the source of water masses, ocean circulation, and climate changes through time. When forams die, their shells are incorporated into deep-sea sediments, so all we have to do is dig up old ocean mud and then we have a record of what the ocean was like a long time ago.

The time period I am studying is important because the global climate was changing from very warm (much warmer than today) to very cold conditions, and ocean circulation was changing. Atmospheric carbon dioxide was much higher than today but declining, which cooled the climate enough that ice sheets developed on Antarctica. As a result of many of these changes certain groups of foraminifera went extinct. I am trying to find out how these climate and ocean changes occurred in the Gulf of Mexico and the Caribbean Sea in the hopes that it will help us understand how modern ocean circulation developed and how it may change in the future as atmospheric carbon dioxide levels continue to increase.

Image of 10 Nuttallides truempyi foraminifera to be analyzed for isotope data. My fingers provide some scale of how small the shells can be.

 

Why did you leave the military to pursue science? I joined the military at age 19 due to lack of employment opportunities and an inability to pay for college. After enlisting, the Air Force trained me in Dari, one of primary languages spoken in Afghanistan. I was a Dari Linguist for six years and reenlisted during my deployment to Afghanistan for four more years. Learning Dari not only gave me a unique appreciation for the Afghan culture but also exposed me to broader geopolitical issues I was previously sheltered from.

Image of me shortly after reenlisting while deployed to Bagram Air Base, Afghanistan, in Dec 2011.

Growing up in southern California, I am familiar with earthquakes, but have been fortunate to not have been significantly affected by them. While deployed to Bagram Air Base in Afghanistan, a northern province in the country experienced a larger magnitude earthquake, resulting in significant damage and casualties, with an entire village swallowed by a landslide. It struck me that a similar magnitude earthquake in the US would not have resulted in the same level of devastation primarily due to the emergency infrastructure of the US and building safety requirements. It made me reconsider what my efforts in Afghanistan were actually resulting in and whether or not I could have a more positive impact on the people I was trying to help.

After my deployment, I began considering what options I might have when my enlistment was up. I decided I wanted to pursue a science career, with the original goal of studying earthquake hazards. I hoped that my military experience would aid in increasing earthquake preparedness and mitigation efforts in countries like Afghanistan.

Me aboard the R/V Brooks McCall in Galveston Bay, Texas, during the Marine Geology Geophysics Field Course in 2018.

Why did you decide to study paleoceanography? After my second enlistment was up in 2015, I moved to Austin and went to Austin Community College (ACC) in preparation for applying to the University of Texas at Austin. While at ACC, I participated in a summer research program where I worked on a group project in a lab studying the permeability and porosity of different types of rocks (how much fluid can flow through certain types of rocks). This experience helped solidify my desire to study geology at UT and gave me confidence in my ability to conduct scientific research. It also instilled in me the importance of promoting participation of 2-year college students in scientific research.

My original goal was to study earthquakes and earthquake hazard mitigation, but my participation in UT’s Institute for Geophysics (UTIG) Marine Geology and Geophysics Field Course introduced me to marine geology, oceanography, and – more importantly – forams. I was fortunate enough to be able to work on an undergraduate research project with UTIG Research Scientist Dr. Chris Lowery using foram ecology to study sea level change along the Texas Gulf Coast over the last 10,000 years. That project, along with Dr. Lowery’s mentorship, gave me the confidence to pursue a graduate degree studying ancient climate and oceanographic changes in the hopes that they will help us understand modern ocean and climate stability and potential impacts on vulnerable communities.

Me graduating from home in May 2020. Like many things in the last two years, the in-person graduation ceremony at UT was cancelled because of the pandemic.

Do you have any advice for aspiring scientists? I have a non-traditional path toward science. Although it took me much longer to get to where I am, I believe my experiences make me a better scientist and a more well-rounded individual. I come from a low-middle income socioeconomic background, I served in the military in a completely different career field, and I attended community college before enrolling at UT Austin. These are just a few of what some people might consider obstacles that I overcame to get to where I am now. However, I am who I am because of where I come from, what I have sacrificed for my education, and the path I took to get to this point. As an older student, I feel much more certain in what I want from my education and in my future scientific career. As a military veteran, I have a socio-political perspective that informs my research goals. So, my advice to aspiring scientists is do not be afraid of a non-traditional path. Things like prior work experience and a community college education are benefits because they make you a versatile individual, and able to adapt to changes in ways that students on a traditional path may not be able to. Take advantage of opportunities that may become available to you because you never know where they will take you or how they might change your perspective or your research path.

What do you want your future to look like? My military experience helped me realize how important it is to me to have a positive impact on the lives of others. After receiving my PhD, I hope to find a position working for a government agency like the US Geological Survey or the National Ocean and Atmospheric Administration. I would like to work on scientific research that informs policy decisions pertaining to climate change impacts, particularly for marginalized communities that are typically more vulnerable to climate change and are underserved with respect to mitigation efforts.

Note from the TS Team: Patty has also written a post on the Student Veterans Research Network that we encourage you to read. 

A new decapod species in Morocco gives insight into ancient Atlantic connections

First report of Early Eocene Decapods in Morocco: description of a new genus and a new species of Carpiliidae (Decapoda: Brachyura) with remarks on its paleobiogeography

by: Àlex Ossó, Julien Bailleul, Cyril Gagnaison

Summarized by: Haley Coe (she/her), a senior geology major at the University of South Florida. She plans to attend graduate school with a focus on paleoclimatology, with future hopes of becoming a research professor. She loves dancing, biking, being outdoors, and hanging out with friends. 

What data were used? All living organisms can be classified by the taxonomic rank. This system groups together individuals with increasingly broader likeliness through classifications of species, genus, family, order, class, phylum and kingdom. This article centers around a newly discovered species belonging to the order Decapoda– which include crustaceans such as crabs, lobsters, and prawns. 

This new genus and species, given the name Maurocarpilius binodosus (Figure 1), was discovered in Eocene-aged rocks from Northern Morocco. This discovery is important because the new species resembles other Eocene-age decapods from Portugal, Spain, and Italy. This resemblance suggests a possible connection between ancient waterways at the time of their existence. The authors of this article hypothesize that this new fossil is a physical link between the ancient Tethys Sea (located between modern-day Africa, Asia, and Europe) and the Atlantic-driven Bay of Biscay (located north of modern-day Portugal and Spain). This waterway could have allowed for easy migration of the decapod species. 

Methods: The discovered decapod fossils were found in a tectonically compressed fold-and-thrust belt (a mountainous area that occurs near certain plate tectonic boundaries) near Ouarzazate, Morocco. Through two fieldtrips by geologists of the UniLaSalle Institute in Beauvais, France, scientists discovered various specimens of this new species within the 400m thick interval of Eocene-age rock.

Scientists then categorized the recovered specimen based on physical differences. The newly discovered species, Maurocarpilius binodosus, had an interestingly oval-like, downturned, smooth, wide shell, among other unique qualities. This distinctive physical shape prompted scientists to propose an entirely new genus, Maurocarpilius. Despite the new classifications, the new Moroccan species showed very interesting similarities with decapods from other locations, such as those found in Portugal, Spain, and Italy.

Figure 1: This figure shows different views of three individual specimen of Maurocarpilius binodosus from the early Eocene of Morocco, with a scale bar of 10 mm.

Results: It can be estimated that Maurocarpilius binodosus is related to other decapod species found in northern Italy and the Iberian Peninsula in southwestern Europe. Both decapod populations decreased simultaneously, prompting scientists to wonder how the populations were physically connected.  It was assumed that the ancient landmass containing modern day Corsica and Sardinia (i.e., the Corso-Sardinian Continental Block) separated the Atlantic Ocean from the Tethys Ocean during the Eocene, which would have blocked any migration or exchange between the two regions. However, overwhelming similarities between decapod populations have encouraged scientists to forgo past assumptions and support the idea of an ancient waterway that linked the Atlantic to the Tethys. This connection most likely stretched along what is now the Iberian Peninsula. Modern coastlines, locations of decapod populations, and a proposed waterway connection can be seen in Figure 2.

Figure 2: This figure is a possible reconstruction of a connection between the Atlantic Ocean and the Tethys Sea during the early Eocene. Paying attention to (7) the present-day coastlines, (8) the discovery of Maurocarpilius binodosus, and (9) and (10) discoveries of related decapods, it is easy to imagine the proposed connection through the Corso-Sardinian Continental Block.

Why is this study important? This study is important because the presence of this new species increases the number of recorded decapod species. Morocco is less studied than other regions around the world, such as North America, and any new information considerably adds to knowledge of the geologic record. This discovery also helps paleontologists better understand how organisms may have migrated across oceans in the geologic record. If decapods were able to expand their geographic range due to this ancient waterway connection, other organisms were also likely to utilize it for migration. 

The big picture: Any advancement in paleontology is an advancement for science as a whole. Identifying an error in previous geographic reconstructions can influence future paleontologists, biologists, and scientists in general. This article is just a piece in the puzzle that is the geologic record, beyond just decapods. Paleontology has a broad influence on the understanding of plate tectonics. Discovering geographically separate populations of the same species, or closely related species, can give insight on how the Earth’s tectonic plates were once connected.

Citation: Ossó, À., Julien Bailleul, and Cyril Gagnaison (2020). First report of Early Eocene Decapods in Morocco: Description of a new genus and a new species of Carpiliidae (DECAPODA: Brachyura) with remarks on its paleobiogeography. Geodiversitas, 42(4), 47. doi:10.5252/geodiversitas2020v42a4

Charlotte Hohman, Paleontology Undergraduate and Student Researcher

Charlotte Hohman in the lab making a list of important features on a dromaeosaurid upper jaw (maxilla) bone for her research.

My name is Charlotte Hohman, and I’m a 3rd-year undergraduate at Montana State University.  I am majoring in earth sciences, with a concentration in the field of paleontology. There are  many different aspects of the field that one can be involved in, including but not limited to  research, fossil preparation, education, outreach, fieldwork, digital reconstruction, and art. I  love many different aspects of the field and am using my student years to gather experience in  those aspects and learn from a variety of mentors to prepare me for a career in the field. 

Charlotte Hohman in the lab with a museum curator comparing a broken hip bone of an unidentified hoofed animal to that of Camelops

I first became aware of paleontology as a scientific field in 2018 when I began volunteering at  the Western Science Center (WSC). In California, you need 40 hours of community service to  graduate high school, and I knew the museum was taking volunteers, so I signed up. I started  as a docent the summer before my senior year. In September 2018, the director had me  identify some Ice Age rodent fossils. He asked me to find a way to categorize the fossils, and I  ended up coming up with a categorization method meant to make predictions about the  ancient environment of the site during the Ice Age. The director thought the method looked  interesting and asked me if I wanted to present at a conference. I presented my preliminary  results my senior year of high school at the 2019 Geological Society of America Cordilleran  meeting, where I realized that I definitely wanted to pursue paleontology professionally.  

Since then, I have continued to do research. I conduct student research at Montana State (and  its affiliated museum Museum of the Rockies (MOR)) and the Western science center. I have  co-authored two publications: one on the Pacific mastodon’s (Mammut pacificus) geographic  range (McDonald et al., 2020), and one on the prehistoric horses of the Cajon Valley Formation  of Southern California (Stoneburg et al., 2021). My three in-progress manuscripts focus on how  dromaeosaurids (raptors) grew into adults, horses in southwestern North America during the  Ice Age, and my continued work on the aforementioned rodents! 

Figure 1: the upper jaw of a Pacific mastodon (Mammut pacificus) from eastern Montana. This jaw tells us that this species of mastodon lived further east than we previously thought. From McDonald et al., 2020.
Figure 2: Teeth from horses that lived in Southern California around 18.0–12.7 million years ago. From Stoneburg et al., 2021.

But as I mentioned, paleontology is so much more than research, and I am involved in multiple  other aspects of the field as well. I have been able to go on digs in New Mexico in Cretaceous  rocks (79 million years old), and in Southern California in Miocene rocks (15 million years old). I  prepare fossils at both the MOR and WSC, and have been fortunate enough to clean the fossils  of whales, sauropods, bison, and more!  

Charlotte Hohman in the lab taking photos of a fossil in a plaster jacket on a cart to build a 3D photogrammetric model.

At the WSC, I make casts, molds, storage cradles, and create 3D models of fossils. All these  lab skills are important for the sharing of research— open-access digital models allow  researchers from around the globe to view your specimens. Casts and 3D prints are great for  outreach and education. I believe that sharing the science is equally as important as doing it,  which is why I am also active in scicomm, or science communication. Science communication  can be online, like on social media, or in-person, like at outreach events. For the WSC, I am the  illustrator of their children’s book series on scientific papers for kids. I run my own educational  account on Instagram, along with managing social media for other paleontology-focused  organizations. Many people have a natural interest in prehistoric animals, so I use science  communication about prehistoric life as a way to draw people in and introduce them to many  different concepts within earth science and biology. 

I plan on doing a Ph.D. when I am done with my bachelor’s and would like to work in a  museum setting one day, to be able to continue to do research, while continuing to share and  teach others about earth history.  

Charlotte Hohman at an outreach event talking to a couple with lots of ice age fossils  laying out on a table in front of her
Charlotte Hohman at an outreach event talking to a couple with lots of ice age fossils laying out on a table in front of her

 

Charlotte Hohman stands in front of badlands dressed for fieldwork, including hat and  backpack
Charlotte Hohman stands in front of badlands dressed for fieldwork, including hat and backpack

 

Charlotte Hohman sits using a mallet and chisel on rock surrounding bone at a field site  in the desert
Charlotte Hohman sits using a mallet and chisel on rock surrounding bone at a field site in the desert

 

Charlotte Hohman uses an air scribe on the rock surrounding ribs of a fossil bison  skeleton to free the ribs
Charlotte Hohman uses an air scribe on the rock surrounding ribs of a fossil bison skeleton to free the ribs

 

Charlotte Hohman stands on a bench inside a museum helping paint a mural of a  Cretaceous forest with two other people
Charlotte Hohman stands on a bench inside a museum helping paint a mural of a Cretaceous forest with two other people

References:

Stoneburg, B. E., McDonald, A. T., Dooley Jr, A. C., Scott, E., & Hohman, C. J. (2021). New  remains of middle Miocene equids from the Cajon Valley Formation, San Bernardino National  Forest, San Bernardino County, California, USA. PaleoBios, 38. 

McDonald, A. T., Atwater, A. L., Dooley Jr, A. C., & Hohman, C. J. (2020). The easternmost  occurrence of Mammut pacificus (Proboscidea: Mammutidae), based on a partial skull from  eastern Montana, USA. PeerJ, 8, e10030. 

Comparing Diatom Paleo-Assemblages to Determine How Different Environments Affect Diversity in the Geological Rock Record

Comparison of Diatom Paleo-Assemblages with Adjacent Limno-Terrestrial Communities on Vega Island, Antarctic Peninsula 

By: Marie Bulínová, Tyler J. Kohler, Jan Kavan, Bart Van de Vijver, Daniel Nývlt, Linda Nedbalová, Silvia H. Coria, Juan M. Lirio, and Kateřina Kopalová

Summarized by: Dani Storms, a senior undergraduate student at the University of South Florida seeking to earn a degree in Geology with a concentration in geophysics. Dani changed her major from English to Geology her sophomore year after taking an Introduction to Earth Science class taught by Dr. Sarah Sheffield. Dr. Sheffield played a significant role in helping her discover a love and curiosity of how geology shapes our everyday lives. She is interested in furthering her education by attending graduate school to earn a master degree in the field of natural hazards, preferably landslides or avalanche control. She hopes to eventually obtain a PhD as well. Dani has loved being in the outdoors her whole life. In her free time, she enjoys hiking, camping, biking, crocheting, and spending quality time with her pup, Zion. 

What data were used? Diatoms are extremely abundant microfossils that are composed of silicon dioxide (SiO2) and can be used to reconstruct different environments through the rock record (i.e., paleoenvironments). This study used statistical analysis to discover if there was a significant difference of diversity within diatom assemblages from core samples derived from two Antarctic lakes, both with varying habitats. Core samples contain sediment that was deposited in paleoenvironments and obtained by drilling into the earth, and these can give insight into how climate has changed over time. The lakes were on Vega Island, in Devil’s Bay (Lake Anónima) and Cape Lamb (Lake Esmeralda). 

The samples were viewed under 100x magnification in order to determine diatom species. The species were then categorized into sub-Antarctic, Maritime Antarctic, and Continental Antarctic groups to determine their biogeographic distribution. Samples were taken from ponds, streams, mosses, and steep habitats to compare the core samples to modern day environments. However, not enough data could be collected from the stream, mosses, and steep habitats for a fair comparison. Therefore, the comparison of habitat differences on different sides of the island was restricted to only ponds.

In order to determine if there was a significant difference between the distributions, the study considered relative abundance, species richness and evenness in relation to diatom counts. Relative abundance refers to the percentage of diatoms found in each sample, richness is the number of species found in the sample, and evenness is comparison of the relative abundance of each individual species. 

Results: Overall, diatom assemblages varied in composition significantly, most likely due to the differences in waterway connections between sites and due to some sites being isolated. Between the categories, Maritime Antarctic Region contained the greatest number of species. Nearly 43% of the taxa found on Vega Island were Antarctic in distribution, while only 6% were found within the Antarctic Continent. Sub-Antarctic accounted for 3% and less than 1% were contributed by the Antarctic Region. The study then addresses the most abundant genus and species within Lake Esmeralda and Lake Anónima. Between the 132 species observed, 100 were found within Lake Esmeralda and only 32 species were found in both lakes. This means that Lake Esmeralda has a greater richness since it contained more species. 

Lake Anónima was found to be most similar to modern environments with the most noteworthy similarities being derived from streams on Devil’s Bay. However, there were several species found only within the core sample containing the paleo-assemblage. The paleo-assemblage consisted primarily of pond and stream species. For Lake Esmeralda, many of the taxa were not found within the modern environment at all. The taxa not found in the modern environment contained both aquatic and terrestrial species of diatoms. 

The authors of the study hypothesize that the connectivity of waterways and habitat type contributed to the difference in diatom assemblage structures. Lake Esmeralda is hydrologically disconnected, meaning it does not have connections to other bodies of water. The disconnect would result in less carbon being funneled into the lake from an outside source, which could alter the chemical makeup of the lake, allowing only certain species to survive as pH levels change. There is also a possibility that Lake Esmeralda might have had a higher preservation rate that allowed for a clearer comparison of paleo-assemblages versus modern, which would explain the higher amounts of diversity between the two. 

However, Lake Anónima is the complete opposite. It is well-connected to a stream that allows for the transportation of diatoms. It also has underground drainage that connects it to other lake-systems and surface streams. The study notes that even if the transport of diatom valves were to not occur, the connection of waterways would result in similar hydrochemistry between the connected water and lakes. This could have led to less viable conditions for preservation that could result in the lower amounts of diversity found. 

Figure 3: These boxplots visualize the comparison of species richness (S), Shannon Diversity (H’), and evenness (J’) between Esmeralda Lake and Anónima Lake core samples. The thicker black lines display median values.

Why is this study important? Looking at the conditions in which modern diatoms are found compared to that of paleo-assemblages can help construct a model, or standard, that can be applied to diatoms in the fossil record. This would allow us to reconstruct paleoclimates and trends associated with how they are affected by waterway connectivity. The differences in diatom-assemblages and species could be used as indicators of climate change. The different modern species that were found to be specific to ponds, mosses, and streams could give insight to what type of habitat fossilized diatoms would have been found in. 

The big picture: As the climate begins to warm and ice melts away, the connection between waterways will more than likely increase, this would cause a more uniform distribution of diatom assemblages and loss of diversity due to the similar chemical compositions of the water. The concept of creating a model that can be applied to the differences of diatom assemblages in modern and paleo-environments could essentially allow for paleoclimate and hydrological connectivity reconstruction. For instance, if we found a more uniform distribution in a general area, we might be able to determine if there was more connectivity between body of waters at some point in the geological record. Another example would be how on average, modern-day dry mosses contain fewer species of diatoms than wet mosses. Knowing this, we could analyze fossilized mosses to give insight into whether they would have been dry or wet. We could also use the findings of this study to determine what bioregion ancient diatoms would have been in based off species type and the diversity of the assemblage. 

Bulínová M, Kohler TJ, Kavan J, Van de Vijver B, Nývlt D, Nedbalová L, Coria SH, Lirio JM, Kopalová K. Comparison of Diatom Paleo-Assemblages with Adjacent Limno-Terrestrial Communities on Vega Island, Antarctic Peninsula. Water. 2020; 12(5):1340. https://doi.org/10.3390/w12051340

Kelsey Jenkins, PhD Candidate

I’m Kels, and I’m a PhD Candidate at Yale University in the Department of Earth and Planetary Sciences. I completed my undergraduate in Geology and Geophysics at Louisiana State University, followed by an M.Sc. in Biological Sciences at Sam Houston State University.

What was your path into science? If you ask any vertebrate paleontologist this question, the majority will say, “Uhh, I was five years old once.” I stopped asking other paleontologists because the answer is so predictable, and it’s my truth as well. 

I am from Houma, Louisiana, a region of the country that is certainly not known for its fossils or for an exceptional educational system. Luckily, I had the support of my parents who encouraged their daughter’s unusual fascination with fossils. But, when college came around, I was clueless on how to get an education in paleontology…it’s not as if there was a paleontology degree. I chose a big state school, LSU, because I thought it would have the most resources available to me, and I could figure it out from there. I initially majored in anthropology, thinking that’s what I needed to work on dinosaurs (wrong!), but by luck I signed up for a historical geology class as an elective. The first class covered the history of the earth and the fossil record. I changed my major shortly after to geology, and I navigated my way through the department until I met my first mentors in paleontology, Judith Schiebout and Suyin Ting. They gave me a job in the museum collections cataloging a huge donation of mammal fossils, and I spent two years getting hands on experience and teaching myself basic anatomy and taxonomy. Following that, Patrick Lewis, my M.Sc. advisor at SHSU, offered me a project on a strange little reptilian creature from the Triassic of South Africa which fueled my current love of fossil reptiles, reptilian evolution, and dentition. I’m still working on reptile evolution and functional morphology now in my PhD with Bhart-Anjan Bhullar.

What is your research about? Imagine every reptile you’ve ever heard of, living and extinct: lizards, snakes, turtles, dinosaurs, alligators, mosasaurs, pterodactyls. Now, imagine the grandpa that unites them all, the original reptile ancestor. I research the creatures that lead up to that original reptile ancestor. Those animals represent some of the first widespread colonization of land by tetrapods (four-legged animals), and they preserve some of the first instances of important adaptations seen in modern reptiles. That part of the reptilian lineage holds clues about how to become an effective land animal following the initial embargo from water onto land by more fish-like creatures.

What are your hobbies and interests outside of science? I’m still figuring that one out. I enjoy cooking, hiking, crochet, writing, and spending time with my friends, but it’s not always easy to separate myself from work and research. When you pursue science, you’re pursuing a passion, and you don’t always want to take a step back. But, it’s important to take breaks and stretch your legs, though telling yourself that is sometimes easier said than done. If I can give students any piece of advice: you definitely need to take breaks. Get a hobby. Get several. Find out what else you might enjoy too.

A Model of Sea Star Locomotion Using Tube Feet

Sea star inspired crawling and bouncing

by: Sina Heydari, Amy Johnson, Olaf Ellers, Matthew J. McHenry, and Eva Kanso

Summarized by Max Botwin, a geology major at the University of South Florida. He is currently a senior and will be graduating in Summer 2021. He is planning to move to Texas in May and looks forward to learning more about the world of geology as he works in the field. In Max’s free time, he enjoys playing with his dog Nilla and exploring the local trails around USF’s campus.

What data were used? The model was created by the researchers using parameters that were observed and measured from Asterias rubens sea stars, such as tube foot length during extension or contraction, density of water, buoyancy, and others.

Methods: To effectively model the locomotion of sea stars, the researchers adhered to what they called “hierarchical control laws”, which was the idea that the sea star controls the direction of movement for all of its tube feet, but the power and the recovery from a contraction is determined by each tube foot at an individual level. The researchers observed sea star movement and created a mathematical model to encompass as many parameters involved with tube foot locomotion as possible, including buoyancy of the feet, density of water, extension of tube feet, etc. Researchers were also able to quantify the pull of tube feet from extending and push from contracting using length of tube feet. Researchers were able to use their model and the data they collected to run many simulations with varying numbers of tube feet over different terrain to test the speed, stability, coordination, and overall effectiveness of tube feet locomotion. Examples of the simulations run by the researchers can be found in the link here.

Results: From this study, researchers have found that sea stars give a general command to the tube feet to move in a certain direction, but the power and the recovery from a contraction of the tube feet is controlled by the individual tube feet. This allows for a crawling movement from the sea star which allows it to travel across most terrain underwater and even swim. Tube feet are only effective underwater, since they work through jet propulsion where the tube foot will extend and fill a vacuole with water, then contract and squeeze out that water to propel themselves. The tube feet on sea stars are only related to one another by their attachment to the sea star and nothing else; there is no communication between the tube feet. Despite this, tube feet seem to fall into coordinated movements, where some tube feet are angled backwards and push forwards and some are angled forwards to “pull” the sea star forward. This pseudo coordination of movement is not limited to tube feet that are adjacent to one another, which means that tube feet can fall into the same locomotion “group”, even though they are not located near one another. When this occurs, the sea star goes from crawling to a bouncing gait which is much faster, but also requires more energy and was therefore found to only be useful under certain circumstances. Researchers saw that sea stars preferred to “pull” when moving vertically and pushing when moving horizontally.

Figure 2 from Heydari et al. (2020). (a) Common sea star used in the study called Asterias rubens. (b) Image of tube feet on Asterias rubens. (c) Image showing the bouncing gait of Asterias rubens. (d) Cross section of Asterias rubens to show the parts of its nervous system. (e) The anatomy of tube feet for mature sea stars. (f) The different actions that tube feet can undertake to perform locomotion. (g) This is a schematic of the mechanical rendition of a sea star including tube feet to help model sea star movement. (h) A flow chart to describe the hierarchical motor control used to command the tube feet in the mechanical sea star.

Why is this study important? This study is important because of the versatility that sea stars have in their movement across most surfaces underwater. If this locomotion can be accurately modeled, it can be recreated for robots, vehicles, or other such applications. The ability to traverse underwater terrain can have impactful applications in many industries that need to do work on the bottom of a body of water. Imagine a vehicle that is able to remain submerged and move along the ground while underwater to repair a bridge or to clean the bottom of a lake- the possibilities are endless!

The Big Picture: This study has shed light on unknown factors involved in how tube feet are controlled by the sea star and researchers were able to study and simulate sea star locomotion but were not able to match the complexity of real sea star locomotion. Answers beget more questions and that rings true here as well; the researchers were able to answer some of the “how” for sea star locomotion but were unable to explain the “why” behind it. This study can be used as a base for future models of the same type and can go further in detail using new parameters and improve their models to better depict the movement of tube feet on sea stars.

Citation: Heydari S, Johnson A, Ellers O, McHenry MJ, Kanso E. Sea star inspired crawling and bouncing. J R Soc Interface. 2020;17(162):20190700. doi:10.1098/rsif.2019.0700

Meet the Museum: Dino Parque Lourinhã

Linda and guest blogger David Kroeck,

During a recent field trip (August 2021), we visited the Dino Parque Lourinhã in western Portugal, approximately 50 km north of Lisbon. Dino Parque Lourinhã is open every day except on holidays and tickets currently cost 9,90 € for children, 13 € for adults, but you can get your tickets at a lower price if you book online [Fig 1].

Fig. 1: Entrance of the Dino Parque Lourinhã with Supersaurus lourinhanensis, a sauropod (long-necked dinosaur) named after the town of Lourinhã.

The park consists of a large outdoor area showcasing life sized dinosaur reconstructions, a small museum as well as an activities hall.

The main part of the park consists of an outdoor space, divided into four zones highlighting the terrestrial fauna of the Paleozoic, Triassic, Jurassic and Cretaceous. A fifth area (called sea monsters) displays a range of marine creatures from different periods, from Jurassic ammonites to Eocene manatees [Fig 2]. A large board near the entrance shows a geologic timescale, depicting the main transitional events and examples of typical fauna and flora for each period [Fig 3]. Five paths then wind through a dense pine forest, hiding even the largest dinosaurs surprisingly well until you stand right in front of them – you never know what lurks behind the next group of trees. The natural cover also provides shade on hot sunny days. Arrows give visitors a chance to walk through the zones in chronological order to experience the evolution of the prehistorical fauna.

Fig. 2: Liopleurodon, an ancient marine reptile belonging to a group called pliosaurs
Fig. 3: Panel showing the geological timescale, including typical fauna and flora and major events as well as the paleogeography.

All displays come with explanations in English, Portuguese, French and Spanish, giving a brief overview of each creature, where fossils have been found, when it lived, information about its diet and hunting strategies, and more. These signs also include pictures of the actual fossils that can be compared with the reconstruction.

The vast majority of reconstructions is rather up to date with the scientific literature; a large number of theropods is shown with a variety of feathers for example [Fig 4]. It is clear that such huge displays cannot be re-done with every new paper that is being published on a certain species, but overall, we found the scientific accuracy of the models impressive. This is certainly due to the very recent opening of the park in 2019. We highly recommend a visit to the park to see brand new dinosaur models. While dinosaurs are, of course, the main attraction of this place, you will also find reconstructions of many different prehistoric animals, such as invertebrates, amphibians, marine reptiles and pterosaurs. All reconstructions were made in dynamic poses, and this artistic choice makes them look alive – guaranteeing great photos [Fig 5]. In total there are more than 180 models.

Fig. 4: Velociraptor, a small, feathered theropod found in central Asia, belonging to a group called dromaeosaurids, also commonly known as ‘raptors’.
Fig. 5: Pterosaurs nesting in a tree in front of the Dino Parque.

For all the very young paleontologists the park has much to offer. Several mini-playgrounds are scattered throughout the exhibits and paleontology is presented in a child friendly manner with a diversity of educational activities and shows. There is for example a sand box in which a plesiosaur replica fossil is hidden so that playing children can excavate it themselves. We also noticed that the only stairs in the entire park are used to access a platform near the head of Supersaurus, a very large sauropod. The rest of the park uses slopes and is thus wheelchair accessible and lots of benches and picnic tables are distributed throughout the entire park so the next place to rest is never far away.

The museum focuses on the rich local dinosaur fauna found in the area, such as a nest of Lourinhanosaurus eggs with embryos inside, and Torvosaurus remains. The museum also explains the local geology and how the area looked like during the Jurassic; it was a meandering river/delta system located in the Lusitanian Basin. Both alluvial and marine fossils are abundant in the sedimentary rocks. More on the geological setting of this area will be covered in a separate blog post where we describe our own fossil hunting efforts in Portugal. The museum also provides an insight into paleontological excavation methods and hosts the preparators’ laboratory, so you can watch people work on newly discovered fossils in real time through a large window [Fig 6].

Fig. 6: Ongoing preparation in the live lab of unidentified sauropod vertebrae found in Lourinhã.

We received a little tour behind the scenes of the park and talked to the preparators who showed us their current projects and were excited to explain the implications of their latest finds. Since these were of course still unpublished, we had to promise to keep everything secret and thus can’t talk about it. You’ll have to keep an eye out for publications on fossils from that area, it’s exciting stuff! Taped to the window to the preparators’ lab was a little poster saying the preparators accept (unpaid) interns/volunteers and people who are looking for thesis projects, so if you are curious about the topic, and excited about learning how to prepare dinosaur or other fossil material, you can apply for an internship there [Fig 7]. Our tour behind the scenes also included very interesting conversations with some of the people who worked on the life-sized dinosaur reconstructions. We got to observe their work for a little bit: they were in the process of creating a copy of a Torvosaurus gurneyi skull replica [Fig 8].

Fig. 7: Information poster for people interested in short or long-term training in preparation techniques, including theses and Erasmus+ mobilities.
Fig. 8: Left: Skull of Torvosaurus, the largest theropod of Europe; right: Preparator working on a mold of the Torvosaurus skull to create a copy of it.

Even without the tour behind the scenes the Dino Parque is definitely worth a visit. Here are some additional impressions of our visit:

Fig. 9 Explorer’s tent with, among other things, geological maps of the area, a poster displaying important dinosaurs from Europe and a globe showing, quite accurately, how the Earth looked like in the Upper Jurassic.
Fig. 10: Supersaurus with two small pterosaurs on its neck. With 45 m length, this model is the largest of the Dino Parque.
Fig. 11: Triceratops stealing Linda’s hat.
Fig. 12: Two Deinonychus stalking their prey. Like their Asian relatives Velociraptor, the North American Deinonychus belonged to the dromaeosaurids (‘raptors’).
Fig. 13: David and the large pterosaur Geosternbergia, falsely labeled Pteranodon (to which it was originally assigned)
Fig. 14: Triceratops skull.
Fig. 15: Lourinhasaurus, a sauropod named after the town of Lourinhã. Linda as a scale.
Fig. 16: Allosaurus with its prey, a stegosaurus. Notice the two juvenile Allosaurus in the bottom part.
Fig. 17: A happy Ankylosaur, an armored-skinned dinosaur.
Fig. 18: Tanystropheus, a long necked aquatic reptile from the Triassic in Europe and Asia. In the background you can see the ancient crocodile Sarcosuchus, a Tyrannosaurus rex and an Ankylosaurus.
Fig. 19: Linda and David unimpressed by the Dilophosaurus’ attempt to threaten them.