Colonization and Sea Level Rise Effects on Carbon Storage in Freshwater Wetlands of Southeastern United States

The Impact of Late Holocene Land Use Change, Climate Variability, and Sea
Level Rise on Carbon Storage in Tidal Freshwater Wetlands on the Southeastern United States Coastal Plain

Miriam C. Jones, Christopher E. Bernhardt, Ken W. Krauss, Gregory B. Noe

Summarized by James Myers who is a graduate student at Binghamton University earning his masters in teaching for earth science. As an undergraduate he majored in environmental
chemistry. Not long after he decided he wanted to become an educator and work towards
creating the next generation of environmental scientists. In his downtime he enjoys playing
guitar, camping, and watching hockey.

What data were used: Sediment cores were collected along the Waccamaw River in South Carolina and the Savannah River in Georgia. The sites were chosen because they have similar landscapes, ranging from freshwater, to moderate salinity, and oligohaline marsh. Four piston core samples were taken from the Waccamaw River, one that was found in freshwater, one in moderately salt-impacted water, and two from the Sampit River, one from a heavily salt-impacted area and one from an oligohaline marsh. Four other cores were collected along the Savannah River using a peat corer. These core sites were also from freshwater, moderately salinated, highly salinated, and an oligohaline marsh.

Three maps of the Savannah river, Waccamaw River, and an inset map showing the location of both rivers along the southeastern United States.
Maps designating the locations of the sites sampled. The sites are roughly 150 km away from each other, along the southeastern coastline of the United States. The Savannah River sites are found further upstream compared to the Waccamaw River sites. The cores at both locations were assigned numbers from one to four. The lower numbers are further upstream and are lower in salinity.

Methods: The cores were dated using radiocarbon analysis on macrofossils and bulk sediment which helped determine which samples were from the colonial era. Time scales were reported with calibrated years before present from 1950. Core compression was apparent within the samples, and bulk density (weight of sediment in a given volume) and accretion rates (how fast sediment accumulates) were adjusted to account for this. Carbon content was calculated using the loss on ignition method. Carbon accumulation rates were calculated by multiplying the percent carbon by the bulk density and accretion rate determined from an age-depth model. Pollen analyses were run to understand which plant species lived at these sites over time, as this method revealed what the environment must have been like if certain plants and trees were able to survive.

Results: The core samples from the Waccamaw river dated between the last 1,100-4,200 years. The oldest sample was the heavily salt-impacted site, which began as a back swamp environment, where fine silts and clays settle after flooding which create a marsh-like landscape. This was determined from the presence of Nyssa, Taxodium, and Poaceae pollen. The accumulation rates are low, but still higher than the freshwater sites. Upper freshwater and oligohaline sites were also found to have been back swamps due to the presence of Alnus in the freshwater core, and Liriodendron tulipifera seeds found at the oligohaline marsh site, as well as Nyssa, Taxodium and Alnus pollen found at both sites. The accretion and accumulation rates are similar to the heavily salt-impacted site. Freshwater environments are characterized by low accretion and carbon accumulation. Higher accretion and carbon accumulation rates are found around 1700-1400 calibrated years before present, and can be seen in the cores with a decrease in hardwoods and increasing Nyssa, Taxodium, and Liriodendron evidence. The largest observed changes happened around 400 years ago, the same time of colonization and the increase in agriculture within the regions. The changes are marked in the cores by large increases in accretion, organic matter, and carbon accumulation. Another indicator of this is the increase of Poaceae, while evidence of Nyssa, hardwoods, and Taxodium diminish. Poaceae pollen and the presence of Scirpus and Carex seeds suggests a change to oligohaline marsh in relation to the increase of land use in the area. Reforestation efforts over the last 100 years show a decrease in accretion and carbon accumulation in all sites. The Savannah River cores were found to be roughly five to six thousand years old. The results from the cores along the Savannah River were found to be very similar to those from the Waccamaw River.
The study revealed that the same zones were also back swamps and that the freshwater core showed low accretion and carbon accumulation. The presence of Alnus designated this back swamp environment. Around 2,000 calibrated years before present, the sites show various changes in biota, but very little change in accretion and carbon accumulation rates. The largest change in the Savannah samples are found around 400 years ago, as was seen in the Waccamaw cores. All sites showed a decline in Nyssa, and an
increase in Poaceae, and what the researchers call weedier taxa, such as Scirpus, Sagittaria, and Polyganum. Both the Savannah River and the Waccamaw River both show stark increases in carbon accumulation and accretion rates right at the start of when colonization and agriculture increased in these regions dramatically, as well as when sea-level rise began to increase during the Holocene. The lowest accretion rates were found further inland, which is tied to an expansion of the marsh. Reforestation efforts coincided with lowered accretion rates, which increased the vulnerability with a rise in sea level. The tidal freshwater forested wetlands are vulnerable to the smallest of salinity changes.
Why this study is important? Wetlands like the ones studied in this research, are important for coastal communities because they help mitigate flooding and support many organisms, as well as fisheries, which provide millions of dollars in commercial and environmental goods and services. Wetlands are also important carbon sinks and help control the amount of CO2 in the atmosphere. Sea level rise today will affect these ecosystems and the people living near them. The results of this research are important for understanding the future long-term resilience of these ecosystems and what measures will be best suited to support these environments.
The big picture: The paper looked at evidence within sediment cores to understand the changes in carbon accumulation and accretion within two southeastern United States rivers. Core evidence indicated that there were increases in accretion and carbon accumulation rates with the emergence of colonization and agriculture in the area. Reforestation efforts in the last 100 years showed a decrease in accretion. The findings were then compared to sea level rise data to show that these environments become more vulnerable with increased sea level rises over the last 200-100 years. This research will be helpful in understanding the effects sea level rise in the future will have on this environment and the surrounding communities.
Citation: Jones, M. C., Bernhardt, C. E., Krauss, K. W., & Noe, G. B. (2017). The impact of late Holocene land use change, climate variability, and sea level rise on carbon storage in tidal freshwater wetlands on the southeastern United States coastal plain. Journal of Geophysical Research: Biogeosciences, 122(12), 3126–3141.

How global warming is changing the ecosystem in the Alps and Apennine Mountains

Assessment of climate change effects on mountain ecosystems through a cross-site analysis in the Alps and Apennines

Rogora M., Frate L., Carranza M.L., Freppaz M., Stanisci A., Bertani I., Bottarin R., Brambilla A., Canullo R., Carbognani M., Cerrato C., Chelli S., Cremonese E., Cutini M., DiMusciano M., Erschbamer B., Gogone D., Iocchi M., Isabellon M., Magnani A., Mazzola L., Morra di Cella U., Pauli H., Petey M., Petriccione B., Porro F., Psenner R., Rossetti G., Scotti A., Sommaruga R., Tappeiner U., Theurillat J.-P., Tomaselli M., Viglietti D., Viterbi R., Vittoz P., Winkler M., and Matteucci G.

Summarized by Agnes Wasielewski, who is an MAT Earth Science Graduate student at Binghamton University. She loves Geology so much that she decided to share her passion with middle and high school students by becoming a teacher. When she’s not studying Geology or the psychology of teenagers; she spends a lot of time with her husband, three children, and three dogs. When free time becomes available, she loves to read, hike, drink tea, and take naps with her dogs.

What data were used? Researchers collected data from twenty research sites across the Alps (Italy, Switzerland, and Austria) and Apennines Mountains (Italy). All sites were located between 1300 and 3212 meters above sea level. Fourteen sites are in forests, grasslands, alpine tundra, and snow-covered areas. Six sites are in lakes and rivers. All sites considered for the paper experienced an increase in air temperature over the past two decades (1991-2015) compared to a base period of 1961-1990. A combination of data analysis on already existing datasets, projects, and new collection of data to determine results.

Methods: Temperatures taken in June were used to determine snow melting rates, the timing of the beginning of the growing season, and timing of ice-break in lakes and rivers. To analyze regional snow cover duration, data loggers combined with thermistors (special resistors used  for temperature measurements) were placed at a soil depth of 10 cm and measured hourly. If the temperatures measured remained within a certain range, the day was considered a “snow cover day”. On days where the daily mean soil temperature dropped below and rose above 0 degrees Celsius, they were labeled as a freeze/thaw cycle. The snow melting date is identified by counting the days since October 1st to the start of the freeze/thaw cycle or melting period. Soil samples were collected in September at the end of the growing season and tests are run to determine water content, carbon content, and nitrate concentrations. 

Changes in vegetation cover were calculated by estimating the percentage of each plant species in permanent grids over time. These estimates are used as a proxy for above-ground biomass. Biomass is positive when vegetation cover increases and negative when cover decreases. 

Surface water samples for chemical analysis were obtained from lakes in late summer/early autumn. May to October is considered open water season, and water temperatures combined with chlorophyll-a concentrations and zooplankton abundance are recorded. Weather stations were used to collect average air temperatures. Biologic samples were analyzed from rivers at varying distances downriver of melting glaciers to correlate community composition and diversity.

Location of research sites where data was collected throughout the Alps and Apennine mountains in central and northern Italy, southern Switzerland, eastern and central Austria.
Location of research sites used for analysis within Italy, Switzerland, and Austria. Degree of temperature change from the baseline reflecting global warming.

Results: At lower altitudes (~1500 meters above sea level) and latitudes (Lat. 41 degrees N), there are shorter snow cover duration (less than 100 days/year) and snow starts to melt earlier in the year. At higher altitudes (~2800 meters above sea level) and latitudes (Lat. 46 degrees N), there are longer snow cover duration periods (~250 days) and snow starts to melt later in the year. Less snow-covered days allow for increased soil temperatures and more areas for plants to grow and thrive. When more plants can grow and thrive, there are more resources available to local wildlife such as the Alpine ibex (mountain goat) and helps support their population growth. Overall, increased air temperatures and soil temperatures showed a general tendency towards increased vegetation cover for treeline, subalpine, and alpine belts but not in the snow (nival) belts. Over the last fifteen years, it is noted that plant species have been migrating from lower elevations to higher elevations in a process called thermophilization.

An increase in nitrogen deposition has positive effects on tree growth and promotes carbon sequestration (the process of capturing and storing atmospheric carbon dioxide). However, reduction in rainfall can override the positive effects. In the forests tested, a significant increase in the growing season length and a general increase in the annual net carbon sequestration was detected.

During warm and dry years, alpine streams transport concentrated solutes into the lakes and in the runoff water. Over the past decade, there has been a common trend in decreasing nitrate concentrations. Nitrogen uptake in the lake catchments has increased due to the increase in primary productivity (algae and vegetation growth). There has an overall negative trend in NO3 concentration level in rivers and lakes due to decreasing Nitrogen deposition. 

Changes in water mineral and chemical concentrations also affect the diversity and population of algae and plankton that live and thrive in mountain lakes and streams.

Why is this study important? Climate warming effects, changes in rainfall seasonality, and water availability have proven to be important for ecosystem productivity. Snow cover duration affects soil carbon and nitrogen cycling and Alpine ibex population dynamics. Warming climate change has shown to lead to an increase in vegetation cover in grasslands and carbon uptake in forests which helps remove CO2 from the atmosphere. Climate drives changes in water chemistry, lake thermal dynamics and plankton phenology can inform us of the health of the water ecosystems. High-elevation ecosystems may also be affected by extreme climatic events such as heat waves, droughts, heavy rainfall, and floods. Both long-term and short-term (extreme) events can affect mountain ecosystems. Mountain ecosystems, if properly studied and monitored, can serve as early indicators of global changes.

The big picture: Global warming affects high mountain ecosystems by increases in temperature, early snowmelt, and a prolonged growing season. With ecosystem productivity, more plant growth helps reduce global climate change by reducing the amount of carbon dioxide in the atmosphere. In mountain ecosystems, carbon sequestration depends on both water availability (precipitation) and air temperature. The understanding of hydro-ecological relationships is essential for the development of effective conservation strategies for alpine rivers. Long-term observations on benthic communities help with the assessment of the potential impacts of global change on stream ecosystems. There is a great need for strong partnerships in mountain ecosystem observation and research for multidisciplinary approaches, encompassing the distinction between different types of ecosystems. There is great potential for further scientific advances that rely on international collaboration and integration.

Citation: Rogora, M., Frate, L., Carranza, M. L., Freppaz, M., Stanisci, A., Bertani, I., Bottarin, R., Brambilla, A., Canullo, R., Carbognani, M., Cerrato, C., Chelli, S., Cremonese, E., Cutini, M., Di Musciano, M., Erschbamer, B., Godone, D., Iocchi, M., Isabellon, M., … Matteucci, G. (2018). Assessment of climate change effects on mountain ecosystems through a cross-site analysis in the Alps and Apennines. The Science of the Total Environment624, 1429–1442.

Society of Vertebrate Paleontology 2021 Annual Meeting & their Paleobiology Database Workshop

Ibrahim here – 

The Society of Vertebrate Paleontology (SVP) is an organization with a goal of advancing science in the field of vertebrate paleontology worldwide. It was founded in the United States in 1940 and consists of approximately 2,300 members internationally. Every year SVP arranges an annual meeting with vertebrate paleontologists, writers, students, artists, and fossil preparators to share the latest research techniques, opportunities, workshops and also includes a prize giving ceremony. 

In 2021 I was lucky enough and won the Tilly Edinger travel grant of the Time Scavengers to attend The 81th annual meeting of Society of vertebrate paleontology (SVP). In 2020 it was my dream to attend the SVP annual meeting and the next year my wish was fulfilled, for this I especially thank the Time Scavengers team for providing me this opportunity. 

Due to Covid-19 the SVP annual meet has been held on an online platform since 2020 otherwise it would have occurred physically. Consequently I attended the 2021 online meet and it was quite easy and comfortable to attend . The event was held from 1st to 5th November and the virtual platform website became available from 25th October. The virtual platform had a simplified page by which one can easily click and view and attend the meeting they want. The talks , Romer prize and posters were recorded and uploaded on that site. Only networking sessions were done live. From the recorded talks I listened to the talk of Albert Chen et al. about phylogenetics insights from the pectoral girdle and forelimb skeleton of crown birds.

The coffee break session was interesting. The Remo app worked like a virtual hall room where anyone can walk around and have a sit and can talk to each other. 

On November 1st I attended the Paleobiology Database Workshop on Zoom, it was guided by professional group leaders (Mark D. Uhen, Evan Vlachos, Matthew Carrano, Pat Holroyd). It was my first time to visualize data from a systematic database. I enjoyed it very much as they were very helpful to show how to use the data from the Paleobiology Database (PBDB). PBDB is an online resource that includes data on fossil occurrences all over the globe. It is a community resource that is added to daily by scientists from around the world. The most iconic of the PBDB website was the navigator, where fossil discoveries are represented by dots in map view. If someone wants to study the fossil record of a taxa over chronological order it is also possible to view and collect data. It can show the diversity plotted on the map overtime. 

More data can be accessible if someone is an approved user. Everyone in the workshop was an approved user. The benefit of an approved user is that one can add data on the website. “Taxonomic name search form” can help to find out necessary data about a taxa and from where you can download the whole database about the taxa in Microsoft Excel file. Another helpful feature of the PBBD is you can find images from a ePanda API system of your required data to retrieve images from the iDigBio system. 

As a student of Geology with a great attraction to vertebrate fauna (especially dinosaurs), I enjoyed the Society of Vertebrate Paleontology’s annual meeting and would love to join an in person meeting in future if I get an opportunity.

Life Decisions

Anieke here–

It took a while, but I finally no longer feel like an imposter. My postdoc is going well. I’m confident, I know what I’m doing and I’m loving it. But the project is coming to an end and I have to think about the next steps. I’ve been in my current institute for nearly nine years, a mind-bogglingly long time in Early Career Researcher world, so a new job likely means a new institution. Quite possibly in another country, given the tight job market. Career-wise, I really like the idea of moving around the world for a few more years, work in different labs and do cool research with cool people.

Life-wise, I want to settle down, buy a house, and figure out if I want kids.

I’ll be 33 this year. After the age of 35 a woman’s chances to get pregnant decrease rapidly. These next few years, that career-wise are best spent hopping across continents, are also my last chance to have a family.  

That is, if I want kids at all. Which right now I really don’t know. I’ve always liked kids but never thought of myself as a mum. The time constraints are making this topic an increasing source of stress but I’m no closer to an answer. So what do I do with my job? Rule out major career options in favour of life question that I’ve not figured out yet? Or just go ahead with the postdoc route, likely involving some long-distance relationships with my partner and hope that life will sort itself out eventually? If I went with option 2 and changed my mind, I could always quit the post early to move back to my partner and try and start a family. But it won’t look great on my cv to walk away from a fellowship half-way through. In the hyper-competitive academic world, the tiniest drawbacks can cost you grants and job interviews.

Alternatively, my partner and I could both move. He’s super kind and supportive and would be up for it if I asked. But it would mean dragging him away from his job and life here for a temporary stay abroad. Plus, moving country is hard. It’s enriching, exhilarating and fantastic, but also terrifying, draining and lonely. If that’s how I felt moving for a job I loved, moving country for no reason other than that your partner is going will be even harder. What it would be like while at the same time trying to start a family, I don’t even want to know.

Early-career researchers hoping to balance work and life have to jump through nearly impossible hoops. I’m fully sympathetic to anyone, with women being statistically more likely, ending up leaving academia for this reason. There just aren’t any good solutions. All we can do is figure out which one is the least bad for us.


Brittany’s AGU Fall Meeting 2021 Experience

Brittany here – 

In December of 2021 I was able to attend the American Geophysical Union’s (AGU) Fall Meeting, my first in-person conference in the last two years, thanks in part to Time Scavengers Tilly Edinger Travel Grant. This was the first AGU Fall meeting presented in a hybrid format, with sessions accessible to those who attended in person, as well as those who chose not to, or could not travel to attend. As the completion of my PhD studies is fast approaching, I saw attending in person to be a beneficial experience for my continued growth as an early career scientist.

The AGU Fall Meeting banner, which reads 'AGU Fall Meeting, New Orleans, LA & Online everywhere 13-17 December 2021'

This year’s fall meeting was different in other aspects than just going hybrid. AGU prioritized safety measures for those attending in person. Masks were to be worn at all times while inside the conference hall, and proof of vaccination needed to be submitted to attend. It was the first meeting where I have experienced an outside coffee hour, which provided a means of social distancing while still getting a much-needed hot drink. Treats local to New Orleans were also served, such as beignets and bread pudding. More importantly, AGU used a new format for oral sessions, where a longer format talk was uploaded to the meeting portal for attendees to watch in advance, and a shorter format talk was presented live during the hosted session. While this format did not appeal to all, it did provide a more equal opportunity for posing questions to the presenters via the mobile app. In this manor session chairs were able to promote engagement between the audience and the presenters, with a much larger diversity of questions being submitted.

A few of the sessions I particularly enjoyed included: Human Responses to Late Quaternary Paleoenvironmental Change, Novel Applications and Technique Advances of Cosmogenic Nuclides, Advancing Research on the Hydroclimate of South America, and Unlearning Racism in Geoscience (URGE) to name a few. As I have been a participant in Northern Illinois Universities URGE pod I was very interested to see how other pods from different universities and colleges across the nation were tackling systemic barriers to those traditionally excluded from the geosciences, and particularly how these issues were being addressed in different sized departments. I really enjoyed watching the panel presentation hosted by members of the URGE leadership team and seeing the changes that so many departments across the country have been able to achieve in only a year. In the associated poster session, it was simultaneously encouraging and frustrating to see that many pods from similarly sized departments as my own often ran into the same issues my pod had experienced in the preceding year. 

A returning feature from previous meetings that I found engaging were the eLightning presentations. In these sessions presenters had three minutes to give an overview of their research, after which attendees were able to circulate amongst the presentations from the session, discussing aspects of the research presented while being able to interact with the presentations on touch screens. One particular presentation where I chatted with the presenter extensively involved computed tomography (CT) scans from soft sediment cores collected from around Antarctica. As I employ the same technique for portions of my own research, I was interested in hearing their experience with the processing software, as well as what other potential complimentary proxies could be used to further assess the data. 

To me, one of the most important facets to attending conferences is the accessibility to connect and network with other scientists. During the pandemic I joined an early career reading group focusing on cosmogenic nuclides, and this meeting provided an opportunity for many of us to gather for the first time. I truly enjoyed meeting these individuals who I had only ever shared a zoom screen with. What made the experience even more fruitful was getting to attend their presentations during the meeting and see how they were applying cosmogenic nuclides to solve various questions involving ice sheet dynamics, geomorphology and even human migration patterns. Furthermore, attending AGU provided a prime opportunity to sit down with collaborators to discuss various projects, as well as meet up with potential post-doctoral mentors.  

Brittany, a woman with brown hair in a green dress, is pictured next to her poster presentation titled “Chlorine-36 Surface Exposure Dating and Glacial Sensitivity Analysis of late-Holocene Moraines, South-Central Chilean Andes (38°S).” (photo credit: Mary Sorensen)
Brittany is pictured next to her poster presentation titled “Chlorine-36 Surface Exposure Dating and Glacial Sensitivity Analysis of late-Holocene Moraines, South-Central Chilean Andes (38°S).” (photo credit: Mary Sorensen)

My presentation was hosted in the Friday afternoon poster session, a notoriously under attended time spot. As in person attendance was much lower than previous AGU fall meetings, the sheer size of the poster hall made it feel rather empty. However, this made for the unusual opportunity to visit the other posters in my session (Changes and Impacts of Climate Variability in South America II), and see other scientific work being done across the Andes and beyond. The work I presented represented the first chapter from my dissertation and a paper that has since been submitted for peer review. Within, we presented the first Chlorine-36 ages of late-Holocene moraines from the South-Central Chilean Andes to compare the timing of southern hemisphere mid-latitude glacial variability with low and high latitude regions. These data were coupled with a tree-ring chronology and are interpreted to represent progressive phases of glacial retreat over the late-Holocene. Additionally, we modeled an envelope of possible forcing parameters based on the location of these glacial moraines and the chronology of glacial abandonment. These results suggest that local glacial fluctuations are sensitive to variability of both temperature and precipitation. 

While the AGU fall meeting may have had a fraction of it’s normal in person attendance, the science presented was just as rigorous, exciting, and motivating as I have grown accustomed to!

Workshop Hosting & Planning: Considerations from an Early Career Researcher

Adriane here–

For the past year and a half, I have been a steering committee member, with the purpose of the committee to develop a series of workshops. In this post, I’ll give some background of the initiative, outline the purpose of the workshops, but mainly focus on factors to think about if you, the reader, are considering creating your own workshop or participating on a workshop committee. 

The International Ocean Discovery Program IMPACT Workshops

The steering committee of which I am a part was formed with significant support from the International Ocean Discovery Program, or IODP for short. IODP is a wonderful program in which scientists from participating countries in the program get to sail for two months at sea on a research vessel, which is currently the JOIDES Resolution (JR), and drill sediment cores from the seafloor (click here to learn more about the JR, where it has most recently sailed, where it currently is, and to read blogs written by scientists currently sailing on the ship). 

Every few decades, the scientific ocean drilling community (the general name used for the community of scientists, artists, science communicators, and others who make the program work) come together to write a science framework. The framework outlines the major approaches and important scientific frontiers for the next phase of scientific ocean drilling. Included in the framework are also some broader impact goals. The new science framework was recently published, which outlines such goals and aspirations through 2050; thus, it is aptly named the 2050 Science Framework. Within the broader impacts section of the 2050 Science Framework, sections are included such as ‘Inspiring Educators and the Public through Discovery’, ‘Training the Next Generation of Scientists’, ‘International Collaboration’, ‘Advancing Diversity and Inclusion’, ‘Knowledge Sharing’, and ‘Engaging with Other Fields’.  

My colleagues and I, who are all passionate about these topics, outlined in the 2050 Science Framework broader impacts section and decided to create a series of workshops to chart the future course of science communication and education outreach for scientific ocean drilling. Such efforts are in direct support of the goals outlined in the 2050 Science Framework. Our steering committee is composed of educators and scientists with various experiences and backgrounds in education, science, and policy, all of whom are passionate about education outreach and science communication. 

We decided to name the workshops the IMPACT Workshop Series, which comprises three workshops that ran this past summer 2021, and a larger workshop to (hopefully!) be held in person in June 2022. We decided to focus on three main topics from the 2050 Science Framework: Engaging the Public, Informing Policymakers, and Preparing the Next Generation. Our main steering committee split into three groups to function as smaller steering committees to create each workshop. Specifically, I was on the Preparing the Next Generation sub-committee with three other steering committee members. 

Factors to consider when hosting workshops

Currently, I am a postdoctoral fellow at a large research university. This means I have lots of responsibilities, the most important of which is to support the students working in my lab and keep doing activities that build my experiences as a researcher, scientist, advisor, and science communicator. In other words, I have a busy schedule with lots to do and keep up with! So, before taking on any tasks or saying ‘yes’ to any opportunities, I need to consider very carefully if such opportunity will be hurtful (take up too much of my time without leading to huge outcomes and do not help build up my experiences), or advantageous (take up my time but lead to very exciting opportunities and build my experiences). In addition, before saying yes to opportunities, I also consider if the opportunity is fulfilling to me and aligns with my passions, self-interests, and goals. This bit is likely true for most early career researchers who are currently looking for permanent employment, are pre-tenured faculty, and others who have limited time but want to be involved with their communities. Thus, the advice below is tailored to help folks who may want to create a workshop or join a workshop steering committee think through the benefits of such an endeavor. 

Carefully consider time commitment and workload

In my opinion, time is the most important factor to consider when thinking about creating a workshop. The IMPACT steering committee met about once a week over a year prior to our first workshop, which ran in June 2021. We met for approximately an hour during our meetings, and because we have members from the east coast of the continental U.S. to Hawai’i, these meeting times were outside of normal workday hours for some of us (e.g., 6 pm EST) — which is not uncommon for projects such as this.

As the Next Generation workshop date approached, our sub-committee began meeting sometimes twice a week, for 2–3 hours per meeting. Such longer meetings were essential to finish outlining, planning, and organizing the workshop. Often, all sub-committee members would walk away from the meeting with a ‘To-Do’ list to accomplish before a deadline we all agreed on. Such tasks outside of meetings included things like drafting and sending emails, writing text for the workshop web pages, gathering resources for our web pages, setting up Google Drive folders, and creating slide shows for the day of the workshops. We also set up meeting times with our speakers prior to our 2-day workshop. All of these small tasks and meetings really added up to a large amount of time. About two weeks prior to the Next Generation workshop, I was spending a good chunk of my time in the office dedicated to planning. 

So, careful consideration should be given to how much time you are willing to contribute to creating a workshop, as the time invested can be immense to make the workshop run as smoothly as possible. Looking back, my time and that of my colleagues’ was a good investment, as I am quite passionate about the topics the workshop touched on and know the information we have gathered will help shape the scientific ocean drilling community. 

Fostering a supportive environment for the team

From the above section regarding time commitments, it should be clear that workshop planning takes a lot of work! It is quite easy to join a committee, board, or group and just jump in without being mindful of our behaviors and simple ways in which we may be excluding others (or being excluded ourselves by others’ behaviors), and working and/or communicating in ways that are ineffective .Thus, it is imperative to consider how you can and will create an environment that is comfortable for everyone to talk, listen, and plan together as a team. 

Along those same lines, it is also important  that the team itself is efficient, mindful of others, and works well together. I feel very fortunate that the IMPACT Steering Committee is composed of folks who have previous leadership experience, and bring a lot of different perspectives to the table. These differing perspectives, experience working with groups, and leadership capabilities have created a space where every committee member’s opinion is heard, and it is a comfortable place to voice my own concerns and opinions. This isn’t to say we always agree with one another (we are human, after all), but having a team that knows how to communicate, compromise, and listen is very valuable. 

When building your own team or committee, it is important to have folks involved who have prior leadership experience and are highly organized. In this way, those who may not have had prior leadership experience can learn from this person, and begin to develop their own methods of and style of leadership. For example, one of our steering committee members has had extensive experience organizing and planning workshops. She suggested we have our speakers meet virtually prior to our workshop in order for them to meet one another, for us to more thoroughly explain the workshop goals, and walk them through the schedule. Even though I have leadership experience, this was a new method to me, and it worked wonderfully! I have also learned a ton of other leadership and organizational tips and tricks from the more experienced members on our committee. 

It is also imperative to build a team of people who represent different identities, life experiences, stages in their careers, and specialities. Our IMPACT workshop steering committee decided from the start that we would conduct the meetings and workshops within a JEDIA (justice, equity, diversity, inclusion, accessibility) framework. Breaking down barriers within STEM, or anywhere, to create a more equitaqble, inclusive, and accessible environment for everyone, is a hard and persistent task, and one that is best done when folks from different identities and backgrounds come together and work hard. This is why it is of utmost importance to be sure you are including folks from different identities on your team. For example, I have had to advocate a few times to my group to please include more early career researchers. Other times, folks have pointed out that all of our speakers on our list of potential invitees were white folks. Every time someone on the team has pointed out an observation that does not align with our JEDIA principles, we have worked hard to correct our actions. Thus, when building your team, think about who is not in the room, and whose voices are being excluded. And it is not enough to simply include folks from different identities; ensure, as a leader, they are being heard and respected by all members of the committee. 

Be prepared to be an effective communicator and listener 

As touched on above, communication is key to any successful relationship of any nature. Working with your colleagues on a steering committee to plan a workshop is no different. Clear and concise communication is imperative to make workshop planning as smooth as possible, and can even translate to a more positive experience for your workshop speakers and attendees. Often, such workshop committees are composed of an array of folks from different backgrounds, life experiences, and ages. This means that everyone’s level of comfort with different means of communication will vary, and the best means of communication should be discussed and respected from the start. For example, the IMPACT committee uses email as our primary way of group communication, but we also set up a Slack channel. In addition, the Steering Committee chairs create an agenda for each meeting, and we take Minutes. In this way, if one of our team members is not able to make a meeting, they can easily see what we discussed and the major points of the meeting.

Good communication also includes speaking up when you don’t understand someone’s ideas or thoughts, or are uncomfortable with the direction in which an initiative is heading. But, good communication is more than talking- it also includes good listening skills. Personally, I am trying to teach myself to be a better active and mindful listener to really hear my friends, family, and colleagues. So, when thinking about planning a workshop or joining a workshop committee, get comfortable with good communication (easier said than done, I know), and be open to being more open with your colleagues. 

Acquiring funding for your workshop 

Often, workshops require some level of financial support. Other workshops, if held virtually, may not require funds. If your workshop does require funding, it is important to think about how much funding (approximately) your workshop will require, and how funding will be obtained prior to the initiation of the project. In my opinion, it is totally okay to reach out to other organizations, non-profits, societies, etc. whose missions align with the goals of your workshop and ask for financial support. In addition, there are pots of money available to support workshops, such as the U.S. Science Support Program and the European Consortium for Ocean Research Drilling’s MagellanPlus Workshop Series Programme (both to support endeavors related to scientific ocean drilling).

Abdur Rahman, Biogeochemist

Hi everyone! I am a postdoctoral candidate at the Geosciences Division, Physical Research Laboratory, Ahmedabad, India. I have recently submitted my thesis and am now waiting for the final defense/viva. My primary research interest is in the field of biogeochemistry in different ecosystems (terrestrial and aquatic) using stable isotopes.

Man and girl in a lab with a yellow wall, looking at vials.
Trying to explain what we do in our lab to a 6th grade student on National Science Day (NSD) in GeoSIL, Physical Research Laboratory. (We were posing for the pic.)

My current research revolves around the biogeochemical study of the early ocean during the late Neoproterozoic-Cambrian transition period. I obtained limestone rock samples from Marwar Supergroup (Rajasthan, India) and am extracting the remnant of ocean life (organic matter) from those rock samples for stable isotope analysis. I will use carbon, nitrogen, and sulfur isotopes of organic matter to address the outstanding questions about the early Earth’s biology and associated biogeochemical processes. I am a curiosity driven early career researcher, always motivated to learn new techniques/methods and gain knowledge that would help develop a better understanding of the Earth’s environment. To expand my expertise, I am also involved in various parallel works. In one of my ongoing projects, I am using black carbon in Himalayan lake sediments (produced during the partial combustion of biomasses) to decipher the paleofire events and vegetation history of the region. I am also involved in the establishment of the clumped isotope measurement of carbonate (speleothems) in our lab. Clumped isotopes are a newly introduced technique to reconstruct the temperature of the water body in which carbonate precipitates.

Man walking in a shallow lake holding a tube, with cloudy sky in the background.
Taking a break to pose for photographs during sample collection for the biogeochemical study.

During my Ph.D., I have focused on the reconstruction of the Himalayan environment and lake biogeochemical evolution using stable isotopes in live- and paleo- lake sediments. My Ph.D. work has covered the last 45 ka of Himalayan environmental history and highlighted various extreme cold periods in the region. In one of the studied western Himalayan lakes, the carbon isotopes of occluded organic matter within diatom frustules have shown the influence of catchment geology on the lake carbon-biogeochemical cycle during 45-29 ka. The nitrogen isotopes of bulk sediments and carbon isotopes of authigenic carbonate and diatom in the western Himalayan lake sediments (Manasbal Lake, Kashmir, India) have shown the influence of climate on the lake stratification and associated biogeochemical cycles. Apart from the impact of natural stress, my Ph.D. also focused on the impact of the increasing human population and associated urbanization on the biogeochemistry of Garud Lake, Nainital, Uttrakhand during the last 70 years. This study has been performed using the stable carbon isotopes of organic matter and black carbon along with the nitrogen isotope of bulk sediments.

What is your favorite part about being a scientist, and how did you get interested in science?

After receiving my high school degree, like any other kid from my village, I was told to go for an early job and get settled. But the rebel child under the guidance of a few wise cousins ended up enrolling for a Bachelor’s degree in Geology at a reputed Central University. Being an avid reader, I connected with the subject in no time. Geology turned out to be more than a mere paper, it took me back to my early village days where I would take several breaks from school to roam around the banks of Ghaghra River (A major tributary of the Ganges, that flows through Uttar Pradesh, India), along with my friends. The little observations made out of sheer curiosity, the colored rocks, the ripples on the sands, the meandering river, all of those childhood observations, all of those many questions and crazy theories made sense then. The time spent in the university and the several departmental field trips brought me a bit closer to nature. Looking at things, sedimentary structures to predict the dip and strikes, it was a fun journey of learning and falling in love with the subject.

Three men in a lake, with their heads just above the blue water, with a blue, clear sky in the background.
Getting relaxed and enjoying the lake with my lab colleague after completing the sample collection.

I eventually followed the course and joined the Masters of Science with Geology as the major. Me and my batchmates were now quite familiar with academia. Like in several other Indian hostel dorms, famous for heated debates and loud late-night discussions we would often end up talking about the career ahead. I still remember that after several long hours, we did manage to agree on a single point, that the most beautiful element a career in research would constantly provide, was the uncertainty in the knowledge acquired and the constant pursuit for truth. For me, pursuing a scientific career means to be a curious student forever in the class of nature.

What advice do you have for up and coming scientists?

Based on my personal experience, I would encourage you to be patient, have faith in yourself, be bold and fierce, and always inspire yourself. In this profession, setting a major goal for a long period of time can be frustrating, so I propose defining small objectives for a day or a week and ticking them off as you move ahead. When you reach your objective, you will feel inspired and happy, which is necessary in our field. Another point I’d want to make is that you should be open to criticism, suggestions, and comments from people both inside and beyond your field of expertise. It aids us in our professional development.

Learn more about Abdur by following him on Instagram, Twitter (@shant_admi), and Facebook!

The Path to Becoming a Paleontologist: Hidden Struggles

This post is part of a series on Time Scavengers about Hidden Disabilities and how these affect scientists and researchers during graduate school, throughout our careers, and in the field and lab.  We welcome contributions from our community, friends, and colleagues to this impactful series.

TRIGGER WARNINGS: Domestic abuse, self harm, suicide attempts, eating disorders

I’ve always known I wanted to be a paleontologist. I was the dinosaur kid and I (kind of) stayed the dinosaur kid. I knew I didn’t look like a paleontologist – all the paleontologists I had seen on TV were white men living their cowboy fantasy, but that didn’t stop me. 

My childhood was spent watching VHS tapes of Walking with…  and Jurassic Park. I would drag my grandfather into the backyard of our tiny apartment complex to look for fossils – often just chunks of limestone with a few bivalves embedded in them. I spent hours at local book sales, looking for old paleontology tomes that I would parse for any bit of knowledge. I began volunteering in our local museum as early as possible and ended up tallying over 300+ hours by the time I finished high school. There was nothing I wanted more than being around the fossils I loved so much.

However, this is not to say there weren’t discouraging moments. During this time at the museum, I learned that museum guests didn’t take me as seriously with my hair down, or that wearing a skirt somehow meant that the facts I was sharing weren’t true. I watched parents shush their daughters and encourage their sons to get excited about the same thing. I heard my mom start repeating their words at home. 

“Stop it. They’ll think you’re weird.”

I started to hate myself, little by little. I couldn’t give up paleontology – it was the one thing I was sure of more than anything – but I hated myself for loving it. This was compounded by the fact that my mother, trying her best to protect me from society’s harsh expectations of women, told me that “boys won’t like [me]” if I kept up this “dinosaur thing”. I’d like to say that this didn’t stop me. I mean, it didn’t stop the paleontology, but I did develop an eating disorder.

There is a common misconception that eating disorders occur because of a desire to be conventionally attractive. That is often not the case. I just wanted to be smaller and have some semblance of control over my life. If you fade into the background, no one notices how you dress like a boy or that your nose is too big or that you can’t shut up about Dilophosaurus. I ended up being significantly smaller – dropping from 140 lbs to 85 lbs in approximately 3 months. Of course, this isn’t normal or healthy for most human bodies. My heart stopped working right. I was hospitalized for anorexia nervosa – a particular type of anorexia that develops in response to anxiety disorders – and missed the last quarter of 7th grade.

The weird thing about being eating-disorder-sick is that people actively encourage you to stay sick. Despite the fact that I couldn’t shower with the lights on or even run without having a heart attack, other students and parents alike told me I was finally “beautiful”. Suddenly, all these boys were paying attention to me. Girls that had bullied me were nice to me. I had my first boyfriend. He told me that when we first met, in 6th grade, he thought I was “fat and ugly” but now I was “gorgeous”. He constantly compared me to my friends. I broke up with him after 5 months. 

It is also important to mention that I was a band kid. Band kids, as the reputation goes, constantly date each other. One of my friends had an obsessive crush on this kid, C. C was quiet. In fact, I had never heard him say a single word during our entire 3 years in middle school band together. I didn’t even know what his last name was. Honestly, he didn’t even seem to have friends – he was always reading and avoiding people whenever we saw him.

Of course, due to middle school peer pressure, we ended up dating.

At first, things were really wonderful. I like to think of him as my first love; we ended up bonding over our mutual love of books and video games. He was the first boy that ever seemed to love me for who I was, and not what I looked like. Due to the large hit to my self-esteem I experienced during my eating disorder and a tumultuous home life, I became increasingly dependent on this relationship. He slowly began isolating me from my friends, insisting that they weren’t good for me or that he absolutely could not stand them. Clinging to him, I cut my friends out with no issue, hoping that it would quell the depression that I had been struggling with. Eventually, he would have anger flare-ups, pounding his hands on the dashboard of the car or throwing things. He began telling me things like, “Oh, I only love you sometimes – you’re not worth it other times.” Things began getting physical, like when he grabbed me hard enough to leave purple-yellow bruises on my shoulders or tried choking me when we got in an argument.

I didn’t leave, though. Not for 5 years. We stayed together through high school and into college, despite numerous suicide attempts on my part, which he encouraged. Somehow, I stuck through. Nothing changed my love of paleontology either; that was the only thing I kept clinging to through all of it. I funneled all that was left of my energy into volunteering at the museum or schoolwork. I knew that if I managed to get into an earth sciences program, I might finally find some sort of peace.

When I was accepted into university, the first thing I did was reach out to our collections manager and begin volunteering in the paleontology lab, months before my freshman year even started. I think I cried actually, when I first walked into the collections. Part of this was joy: it was the first light in a very, very long darkness. The other half was sadness: I had already resigned myself to being killed in a domestic dispute and had mentally given up on my future as my partner became more and more aggressive.

C began using drugs and drinking heavily; during this time, he also got much more erratic and violent. He began making threats towards me and my classmates.

During this time, though, I had managed to build a small, supportive friend group of other geoscience students. As I began opening up to them, I began to see how truly toxic my partner was. These were the first close friends I was allowed to have in years, as C didn’t go to the same college as me and thus, I could experience small tastes of freedom.

Bit by bit, I finally got the courage (and was forced by a mandated reporter) to go to the university police. This was ultimately a very dangerous decision. They notified him that someone at my university had reported him; he got kicked out of his program at his college for substance abuse. Additionally, considering that he was a loner and I was one of his only contacts, he immediately knew that it was me that had reported him. I was also told that none of his texts were immediate threats, so their hands were tied. I stayed with him another 4 months as he became even more erratic. I ended up losing my research position because I had to spend so many hours on the phone convincing him to not do something harmful and scary. I ended up with a reputation for being flaky, despite the fact that I would spend nights scanning fossils while crying into the phone. I couldn’t walk on campus alone anymore and refused to see him, even though we were still technically in a relationship. 

I was terrified that he would kill everyone I knew if I broke it off.

Eventually, I was so exhausted from living in fear that I just… never responded to another text. He responded by calling every member of my family and driving by my house. I ignored him. My family encouraged me to repair the relationship and keep the peace; I didn’t. 

He found new ways, year after year, to contact me and drag me back into his circle of influence. He kept driving by my house. He found new relatives to contact. He sent me letters. 

I found my solace in the museum. I poured every ounce of my soul into paleontology – it was my safe place. I made more friends with similar interests to mine. I became stronger and stronger. He never stopped bothering me, but he became more of a looming background presence than a main presence in my life. I had a home and a family outside of my biological family. I had research that I was immensely passionate about. No one was there to hold me back anymore; yes, C would sometimes send me threatening texts or appear around my house, but this was rare. I finally had freedom and it was amazing.

Eventually, I found my real way out: graduate school. I was able to change my location, and thus, he could no longer find my real position. I have never felt such peace of mind and I have never loved paleontology more. 

Thank you for reading.

Note: Leaving isn’t really an answer, for many people, as not everyone can uproot themselves and escape abusive situations. I urge everyone to find their own way out – my sway is not necessarily the best way to respond to a situation like this; as I said, this is *my* story, and how I managed to find (possibly momental) safety. There are also many details I left out to protect my safety.

If you or someone you love is in a domestic violence situation, the National Domestic Violence Hotline has a list of resources to begin getting help:

You can also call them via:
National Domestic Violence Hotline
1-800-787-3224 (TTY)

If you would like to learn more about eating disorders, Anorexia nervosa and Associated Disorders (ANAD; and the National Eating Disorders Association (NEDA; have resources.

New Fossil Evidence From the Arctic Could Indicate that Mosasaurs Migrated

Arctic mosasaurs (Squamata, Mosasauridae) from the Upper Cretaceous of Russia

Dmitry V.Grigoriev and Alexander A.Grabovskiy

Summarized by Evan Kruse. Evan Kruse is a senior undergrad student at University of South Florida majoring in geology. He plans on attending graduate school in either paleontology or mineralogy. He enjoys hiking, rock tumbling, identifying the rocks that his friends bring to him, and, secretly, he wishes he could bring back dinosaurs and have his own raptor, hence his paleontology major.

What data were used?  New mosasaur fossils, consisting of a vertebral column, isolated teeth, and a jawbone were found by the researchers in the Zolotaya River in the Anadyr district of Russia. Mosasaurs belong to a superfamily of marine reptiles, all of which have a crocodile-like head, lizard-like body, flippers instead of feet, and a long, paddle-like tail. All three types of fossils were found in roughly the same location, within 5 m of each other. The researchers also used older mosasaur vertebrae fossils from Kotikovo, Russia and the River Lemva, Komi Republic, Russia. 

Methods: This study utilized morphological differences, such as vertebral length-to-height ratios and the distinct facets on the tooth crowns, to classify the newly-discovered mosasaur specimen as a member of the subfamily Tylosaurinae. More data is required to fully classify the specimen and for now they are simply classified as Tylosaurinae indet.(i.e., it is currently an indeterminate species within Tylosaurinae) In addition to the newly discovered fossils, the researchers use the same morphological comparative techniques on two other samples previously discovered elsewhere. These other specimens are very damaged and can only be identified as belonging to the family Mosasauridae indet. The researchers also analyze the geographical location where all three specimens, the vertebrae, jawbone, and teeth, were found in reference to their predicted geographical location during the Cretaceous Period, specifically the Turonian, Santonian, Campanian, and Maastrichtian ages. 

This image shows four images of globes as overhead views looking down at the North pole with red stars marked at various locations as well as dashed and solid white arrows. Each globe has a different continental and oceanic layout and represent the predicted layout during different ages in the Late Cretaceous, one each for the Turonian in the top left, Coniacian-Santonian in the top right, Campanian in the bottom left, and the Maastrichtian in the bottom right. Arrows of cold and warm currents in the ocean are on this chart as well; some of the mosasaur fossils found would have been in the cold water currents.
This diagram shows the predicted geographical location where the mosasaur remains referenced in the paper would have died and been fossilized at during the different ages in the Cretaceous Period. The red stars indicate mosasaur locations. The size of the star indicates the predicted amount of fossil remains at the location. Solid arrows represent warm currents; dashed arrows represent cold currents.

Results:  The mosasaur remains found in the paper were discovered in high latitudes in cold conditions. Researchers have studied the continental movements associated with plate tectonics and have predicted the longitudinal and latitudinal location of the remains during the Late Cretaceous when they were deposited. The fossils retain their position in high latitudes which would have been associated with frigid waters. This means that mosasaurs were much more widespread than previously thought and that they were able to survive in colder climates than previously believed. In the past several years, many studies have come out which discuss and theorize about the thermoregulation (i.e.., how an organism regulates their body temperature) of mosasaurs. Although mosasaurs are a part of the same large group as lizards and snakes (who are ‘cold blooded’, basking in the sun to maintain body heat), these new studies postulate that many or all mosasaurs were endothermic (meaning that they could self-regulate their own body temperature) like mammals are. Being endothermic implies that Arctic conditions were not a problem for mosasaurs and that they would have been able to survive staying part or all of the year in the polar seas. Evidence from this study supports this hypothesis. This study also takes the existence of polar mosasaur fossils as indirect evidence of yearly migration patterns. Today, the high latitudes go through extended periods of constant 24-hour light and darkness, a yearly cycle that does not differ much today from the same cycle during the Cretaceous. This study predicts that the polar regions would have at least two months of solid darkness and at least one month of constant twilight. It is unlikely that mosasaurs had binocular vision for nighttime hunting and it is even less likely that mosasaurs developed echolocation (locating objects by reflected sound, like many whales do) to deal with the absence of light. With this in mind, the presence of mosasaur fossils in the high latitudes can be taken as indirect evidence of mosasaur migration patterns, so it is possible that the mosasaurs did not remain in those high latitudes year-round.

Why is this study important?  This study is important because it hypothesizes that mosasaurs seasonally migrate to and from higher latitudes in much the same fashion as our modern-day whales. If this is true, then we may be able to take the patterns and behaviors of whales and apply them to mosasaur behaviors. 

The big picture:  Predicting the behavior of extinct animals is tough; we often have little to go on, except for what we find in the fossil record. By examining the location and preservation state of fossil assemblages, we are able to make certain predictions about behavior. If mosasaurs migrated in similar fashion to modern-day whales, then we can look at other behaviors whales have and make predictions as to whether or not mosasaurs also shared that behavior. We can look for fossil evidence to support or contradict the hypotheses we put out. This can allow us to consider new behaviors for extinct animals we might not have before, change the way we interpret fossil evidence for other species, recognize new patterns in existing data, and make new predictions that may clue us into new ways to look for fossils. 

Citation: Grigoriev, Dmitry V., and Alexander A. Grabovskiy. “Arctic Mosasaurs (Squamata, Mosasauridae) from the Upper Cretaceous of Russia.” Cretaceous Research, vol. 114, Oct. 2020, p. 104499., 

CT analysis shows new relationships of Euryodus, an extinct amphibian

Computed tomographic analysis of the cranium of the early Permian recumbirostran ‘microsaur’ Euryodus dalyae reveals new details of the braincase and mandible

Bryan M. Gee, Joseph J. Bevitt and Robert R. Reisz

Summarized by Danielle Miller, who is a geology major at the University of South Florida, working towards becoming a paleontologist. She loves watching hockey and listening to music. She has two dogs. She also loves spending time out on the boat, fishing, and hanging out in the Gulf of Mexico.

What data were used? The researchers used two specimens that were identified as Euryodus dalyae from the Richards Spur locality, a fossil site in Oklahoma. Researchers compared the specimens of Euryodus dalyae to the holotype fossils of this species; a holotype is a specimen that is used by paleontologists to define a species. These two specimens are gymnarthrids, which belong to an extinct family of amphibians called microsaurs. These new specimens were compared using data that was collected through a type of CT that is called neutron tomography and x-ray tomography. The researchers also performed a phylogenetic analysis to understand how the newly discovered specimens were related to other microsaurs. The researchers created a number of characters based on the cranial (skull) shapes across the taxa used, as well as on the vertebrate of the taxa. The collected morphological data was put into the matrix (i.e., all of the morphogical characters in total) to be analyzed to determine the evolutionary relationships between the specimens.

Methods: The researchers did tomographic and phylogenetic analyses of the specimens. The phylogenetic analyses were done to see the evolutionary relationship between the specimens and the holotype of Euryodus. During the phylogenetic analysis, the researchers coded the two new specimens into a phylogenetic matrix that was created in a previous study done in 2017. Coding of several other microsaurs were used in the analyses. One of the other microsaurs used in the analyses was from the same genus as the new specimens, while the others were from different genera. The analyses were done using PAUP*, which is a computer program that is used to infer evolutionary trees. For the tomographic analysis of the specimens, the researchers did neutron tomography and X- ray tomography. Tomographic analyses are techniques that are used to represent a cross section of solid objects through X- rays or ultrasound. Neutron tomography is performed by rotating the specimens 180°, then taking neutron radiographs, which are photos produced on film by x-rays, at defined angular positions. This can produce a 3D image of a specimen’s composition. 1200 radiographs of one of the new specimens were produced in this analysis. The other new specimen was analyzed using X- ray tomography. The photos from both tomographic analyses were then analyzed in ImageJ, which is an image processing program that can be used to measure and analyze images. 

There are three pictures of the skull of Euryodus sp. Picture A is a triangular shaped, brownish skull shown from the bottom. Picture B is a colorful computer-generated model of the skull in the same orientation of Picture A. Picture C is also a colorful computer-generated model of the skull, but this time it is looking from the back of the skull. The sky-blue colored bone in Picture B is the upper jaw of the specimen discussed in the article. The dark pink bone in Picture B is the mandible also discussed in the article. Pictures B and C have abbreviations pointing out the different bones of the skull.
Figure 1. The skull of a specimen of Euryodus sp. Picture A is a picture of Euryodus sp.’s skull, viewed from the bottom. Picture B is a rendering of Euryodus sp.’s skull in the same profile. This picture has different colors representing the different parts of the specimen. Picture C is a rendering of Euryodus sp.’s skull from the back of the skull angled from the bottom to the top. The colors in the pictures B and C represent different parts of the skull. The colors in C represent the same parts as they do in Picture B. There are abbreviations in pictures B and C that represent the different anatomical parts of Euryodus sp. The abbreviation ‘m’ stands for the maxilla which is the upper jaw and while it is not abbreviated in this photo, the darker pink section is the part of the jaw that was discussed in the article. Scale bar= 1 cm.

Results: The result of this study shows that there is an especially close relationship between one of the recently discovered specimens and the holotype of Euryodus dalyae. The majority of differences between the skeletons are probably due to damage to the specimen over millions of years in the rock record, and not due to biological differences; however, there were some differences between the specimens on the internal portion of the skeleton These two specimens are also very similar to other species of extinct amphibians. The two specimen that were identified as Euryodus dalyae are now described as Euryodus sp. because of this study. Euryodus dalyae and Euryodus sp. look almost the same on the outside, but they are different internally. One such internal difference is the presence or absence of a presphenoid, which is the front part of a bone that is found at the base of the skull of the specimen. The researchers are unsure if these differences are due to ontogeny, the growth of the specimens, or if this is a signal that the two specimens represent different species. This difference is one reason that the researchers encourage more exploration of recumbirostrans, which are the amphibian group that include the family that Euryodus is part of. There was also the presence of an offset partial tooth row in the new specimens. This feature has been seen in a group called the captorhinids, which are lizard-like reptiles. This helps us better identify the broader groups that Euryodus is related to, because the offset teeth are only in certain species. This means that scientists can more confidently say that these groups belong in the same group. However, the offset teeth weren’t identical across the specimens studied here, so further tests need to be done.

Why is this study important? This is important because it provides a new understanding of the Euryodus clade. It can also be used to help determine if microsaurs are really a sister clade (meaning, the most closely related clade) to captorhinids, lizard-like reptiles that ranged from small to large and lived during the Permian, as they have been hypothesized to be before. This study also provides a better understanding of the anatomy of gymnarthrids and other microsaurs. Understanding the anatomy of gymnarthrids and other microsaurs is useful since future researchers can use that data to put other specimen into the group, if they fit that description.

The big picture: If we know the evolutionary relationships between the specimens in this study, then we could start to ask other questions about the group. We could investigate how the group changed across different extinction events or we could better understand the anatomy of these amphibians and see how this anatomy developed in amphibians of today.  

Citation: Gee, B. M., Bevitt, J. J., & Reisz, R. R. (2020). Computed tomographic analysis of the cranium of the early permian recumbirostran ‘microsaur’ Euryodus Dalyae reveals new details of the braincase and mandible. Papers in Palaeontology, 7(2), 721–749.