Paleobiological analysis of the first record of redfieldiiform fish found in Korea from the Late Triassic

The first record of redfieldiiform fish (Actinopterygii) from the Upper Triassic of Korea: Implications for paleobiology and paleobiogeography of Redfieldiiformes

By: Su-Hwan Kim, Yuong-Nam Lee, Jin-Young Park, Sungjin Lee, Hang-Jae Lee

Summarized by: Jonathan Weimar

Jonathan Weimar is a geology major at the University of South Florida. Currently he is a senior and is very interested in space and natural hazards. After he obtains his degree, he plans to research the possible careers that coexist with his interests. Aside from geology, he loves making music and has a dream of becoming a professional music artist. 

What data were used? A new well-preserved fossil of redfieldiiform , a type of ray-finned fish, has been discovered from the Triassic Amisan Formation in South Korea. The fossil slightly differs from the regular morphology of redfieldiiform taxa and therefore, represent a new taxon called Hiascoactinus boryeongensis. 

Methods: The Amisan Formation reaches depths of up to 1000m thick and is broken up into three different sections: the lower member, the middle member, and the upper member. By looking at the floral assemblage of the Amisan Formation, scientists were able to date the depositional age of these fossils to be of the Late Triassic (about 237 million years ago). 

Results: The redfieldiiform fish belongs to the larger group called the ray-finned fishes, which make up the majority of fish in today’s oceans. While there have been many discoveries of the redfieldiiform fish in various continents such as North America and Australia, this is the first valid record of the ray-finned fish in Asia. Even though there have been previous records of the redfieldiiform fish in China, Siberia, and Russia, they have been inaccurate, and therefore the specimen in this article found in Korea is notably the first valid record of redfieldiiform fish in Asia. The redfieldiiform fish has many distinguishable characteristics that include: anal and dorsal fins with membranes between the rays,positioning of the anal and dorsal fins, a single-plated ray, and a spindle shaped body covered with scales. The official name given to the discovered fossil is Hiascoactinus boryeongensis. The genus name“Hiascoactinus” is Greek and Latin- based and refers to the unique dorsal and anal fins, while the species name “boryeongensis” refers to the city of Korea, Boryeong. The fossil has a length of 138mm and a width of 38mm. Almost all of the fossil is intact, except some parts of the caudal fin, furthest from the head, as well as parts of the skull and stomach region. Morphologically, there are differences between the new taxon Hiascoactinus boryeongensis and the redfieldiiform fish that have been scientifically researched. For example, there is a difference that focuses on the dorsal and anal fins of the fish. These fins are what help the fish directionally and are very important. A lot of ray-finned fish erect their fins to quickly get away from predators and go after prey as it helps with turning maneuvers. The dorsal and anal fins of the Hiascoactinus boryeongensis, however, are not fully connected between rays, unlike other closely related fish. This would have made it harder for them to complete turning maneuvers. Because of this, it is suggested that the species was slow swimming predators and went after prey that was inactive.

This figure shows us the specimen of the Hiascoactinus boryeongensis and a recreation of the fossil providing more detail of the structures. Parts of the caudal fin furthest from the head, parts of the skull, and parts of the abdomen are missing. That is an artistic representation of what the specimen could of looked like.

Why is this study important? This study is important for many reasons. Firstly, this fossil is well-preserved, which means that it has the greatest potential of revealing information about its physiology, morphology, and taxonomy. It allows for the study of the redfieldiiform group and provides information about how this species may have lived million years ago (e.g., the structures of the fins could indicate its swimming capabilities). Lastly, it shows that global sampling of fossils can reveal new evolutionary adaptations and biogeographic patterns of different species.   

The big picture: This study provides insight on the redfieldiiform fish and shows us how we can use morphological differences to define a new species. This article also shows us the importance of reevaluation of scientific evidence. The previous records of the ray-finned fish found in Russia and China were inaccurate and provided inaccurate biogeographic information on the redfieldiiform fish record. It was with this study and the well-preserved fossil founded in Korea that shows us the first true record of one of these fish in Asia.  

Citation: Kim, S., Park, J., Lee, S., & Lee, H. (2019). The first record of redfieldiiform fish (Actinopterygii) from the Upper Triassic of Korea: Implications for paleobiology and paleobiogeography of Redfieldiiformes. In 1011400475 778507242 Y. Lee (Ed.), Gondwana Research (Vol. 80, pp. 275-284). Amsterdam, Netherlands: Elsevier. doi:https://www.sciencedirect.com/science/article/pii/S1342937X19303211

Spinosaurus Teeth Open A New Window into the Lifestyle of This Unique Creature

Taphonomic evidence supports an aquatic lifestyle for Spinosaurus

By: Thomas Beevora, Aaron Quigleya, Roy E. Smith, Robert S.H. Smyth, Nizar Ibrahim, Samir Zouhric, and David M. Martill

Summarized by Jerold Ramos  

Jerold Ramos is a senior at The University of South Florida studying geology. Once he graduates, he hopes to develop experience working in a museum environment to one day become a museum educator. Captivated by the beauty and mystery of dinosaurs from a young age, he hopes that as a museum educator he can share the excitement and wonder that Earth’s history has to offer with people from around the world. In his free time, he enjoys hosting game nights with his friends and creating poorly photoshopped projects.

What data were used? Two collections of fossilized teeth found in separate riverbed deposits within South Eastern Morocco were used for this study. In total, 1,245 teeth were collected and sorted into appropriate groups based on their taxonomic order or genus.

Methods: Fossils were collected at two different sites in Morocco. Site One excavated fossils from an exposed bed, while the fossils from Site Two were bought from a mining group that had discovered them previously. Beevora and their team chose to focus on teeth, as they could assign these teeth to a taxonomic order (e.g., Carnivora [dogs and cats], Primates [including chimps and humans], and Saurischia [theropod and sauropod dinosaurs]) or even more specifically to a family or genus level. In this case, Beevora and their team were able to assign many of the teeth to the genus Spinosaurus.

Figure 1. Left: Pie chart displaying the distribution of fossils within Sites One and Two. Charts A and C represent all fossils at Sites One and Two respectively, while charts B and D represent the collection of fossilized teeth. The images to the right represent teeth from Site Two belonging to Spinosaurus (Scale bar- 10mm).

Results: After analyzing the fossils collected from both sites, this study found that the amount of Spinosaurus teeth at each site was abnormally high when compared to the teeth of other creatures found in the area. At Site One, 921 fossils were uncovered and of these 921, a total of 317 of these were teeth. From these teeth, about 47.9% (152) of these teeth were Spinosaurus teeth. The only creature to have a similar count in teeth was Onchopristis, an ancient sawfish from the Cretaceous Period, with 50.2% (159) of the teeth belonging to this fish. At Site Two, 1261 fossils were purchased from a miner and of these 1261 fossils, a total of 928 of these fossils were teeth.  At this location, a greater assemblage of Spinosaurus teeth were identified. Here Spinosaurus teeth made up about 43.9% (407) of the teeth found, making it the most abundant species represented at this site. Once again, the only other creature to have a similar representation at the site is Onchopristis, with 40.4% (375) of its teeth making up the collection found at Site Two. The rich supply of Spinosaurus teeth found at both sites suggest a more aquatic lifestyle for Spinosaurus. From the data collected in both sites, these sites likely represented aquatic environments due to the high presence of teeth from Onchopristis, an entirely aquatic animal, making up about half of the teeth found at each site. A creature that does not live an aquatic lifestyle, or spend a significant time in the water, would not leave as many remains in the environment. As an example, Site One discovered a single tooth from Carcharodontosaurus, another large therapod dinosaur that is thought to be strictly land-dwelling. This single tooth is more in line with what would be expected from a creature with a terrestrial lifestyle as it would only approach the water to drink or feed on a creature nearby. If Spinosaurus was terrestrial like Carcharodontosaurus, then it would not have such a prominent representation at these sites. Rather than wading by the water’s edge like a heron or flamingo, Spinosaurus may have spent much of its time in the water actively swimming to catch prey. This collection of teeth in aquatic deposits and Spinosaurus’ established morphology, including reduced hind legs, elongated skull, and paddle-like tail structure, further support the hypothesis that Spinosaurus lived an aquatic lifestyle.

Why is this study important? The findings from this study change what we know about both Spinosaurus and how we define dinosaurs today. Like other non-avian (i.e., non-bird) dinosaurs, Spinosaurus was often pictured to be a terrestrial creature, only visiting aquatic areas when it needed water. However, thanks to recent discoveries in the last five years, we now know that it likely lived a more aquatic lifestyle. This lifestyle is something that is not seen with any other known non-avian dinosaur so far. Dinosaurs are often defined as exclusively terrestrial creatures, a definition that no longer applies to the Spinosaurus. With the recent discoveries involving Spinosaurus, it may be worth reevaluating the lifestyles of other members of the family Spinosauridae, as it is possible that other Spinosauridae adopted an aquatic lifestyle long before Spinosaurus.   

The big picture: Spinosaurus has been an enigmatic fossil ever since it was discovered in 1915. After its remains were destroyed during World War II, the image and lifestyle of Spinosaurus remained a mystery to paleontologists for several years. Now that more of its fossils are being unearthed, paleontologists can reconstruct this unique creature and illustrate the environment it inhabited. From these recent discoveries, we now know that Spinosaurus lived a life unlike any other dinosaur recorded in the fossil record. As there are numerous dinosaurs missing from the fossil record, whether it be through failed preservation or destruction by plate tectonics, it is possible that there are others that share this aquatic lifestyle.

Citation: Beevor, T., Quigley, A., Smith, R. E., Smyth, R. S. H., Ibrahim, N., Zouhri, S., & Martill, D. M. (2021). Taphonomic evidence supports an aquatic lifestyle for Spinosaurus. Cretaceous Research, 117. https://doi-org.ezproxy.lib.usf.edu/10.1016/j.cretres.2020.104627  

Imaging Technology and its Effect on Interpersonal Relationships in the Paleontology Lab

Trust in Technicians in Paleontology Laboratories. A look into the growing use of computed tomography (CT) imaging and its legitimacy among professional researchers in the lab.

by Caitlin Donahue Wylie

Summarized by Cresencia del Pino 

Cresencia del Pino is an undergraduate geology student at the University of South Florida. After receiving her degree, she intends to join the professional workforce and attain her Professional Geologist title. When she is not studying geology, she enjoys mountain biking, camping and hiking with her pup, Zion. 

What data was used? The author used data from semi-structured qualitative interviews (a set list of questions, but researchers can deviate from them) conducted by researchers, lab technicians, and others in several universities across the United States, Germany, and The United Kingdom from 2009 to 2013. 

Methods: The author created a semi-structured interview to understand professional opinions on CT imaging, fossil preparators, and their role in maintaining a social hierarchy within a scientific research community. 

Results: This study gathered qualitative data on how the emergence of digital imaging techniques has affected the social structures within the lab. The author states a resounding skepticism towards the use of CT scans and images as a proxy for physical fossil specimens. Researchers rely on the trust forged between fossil preparators [people who clean and prepare fossil specimens by chipping away at surrounding rock], over the imaging captured by CT technology. They [professionals in the field] claim that CT imaging is not detailed enough, and subject to too much human error when calibrating the bounds that are used to capture fossil within rock. Therefore, CT imaging should be used as a tool to support fossil discovery along-side true hand samples in a “mixed-method” approach. However, the author notes that this skepticism may stem from innate bias to hold the social structure of the lab constant, where researchers are explicitly or implicitly ranked above lab technicians. 

Synchrotron [a type of digital imaging like CT, where X-rays are used to measure density] image of a burrow that contains two fossils. This image introduces an advantage of digital imaging, where scientists can see inside a rock. This is a faster method than traditional fossil preparation which also preserves the trace fossil of the burrow, as well as the skeletons inside. Source: Fernandez et al. (2013).
Why is this study important? This study elucidates, through interviews, the motives of research professionals being skeptical of digital imaging technology. Although critiques of the technique are valid, it omits otherwise greater advantages, such as being able to see fossil in rock, without the need for skilled, time-consuming preparation. These advantages are overlooked, because the growing acceptance of CT imaging would mean more specialized technicians would be required to combine and create images, leading to a decline in skilled fossil preparators, ultimately upsetting the social structure of the lab. From the interviews, the author notes that there is also an included scapegoat when using digital imaging, that allows disagreements between colleagues to “blame the technology”, instead of the interpretation of their cohort, which ultimately can affect trust between members of the lab. 

The big picture: Technology is advancing at a rapid pace in today’s modern scientific society. In a world where pandemics are a reality, and the need for social distancing and remote learning is a necessity, the demand for digital formats has increased exponentially. Digitized fossil scans can ultimately increase the accessibility of fossils, therefore allowing specimens to be studied remotely from researchers who may not have the privilege, or ability, to travel. There may no longer be room for the stigmatization of digital fossils against traditional hand samples. While technology is still advancing, there needs to be an acceptance for change within the community, and flexibility when it comes to the shifting positions and ranks within the lab. 

Citation: Wylie, Caitlin Donahue. “Trust in technicians in paleontology laboratories.” Science, Technology, & Human Values 43.2 (2018): 324-348.

Glacial mappings of Dronning Maud Land, Antarctica using WorldView satellites

The glacial geomorphology of western Dronning Maud Land, Antarctic

J. C. H. Newall, T. Dymova, E. Serra, R. Blomdin, O. Fredin, N. F. Glasser, Y. Suganuma, J. M. Harbor, and A. P. Stroeven

Summarized by Mia Borja

What data were used? Remote mapping was used to capture the features of Antarctician glaciers via World View-2 and 3 satellite data (satellites that capture specific spatial resolutions to create surficial mappings). These mappings were accompanied with fieldwork to give an accurate depiction of the glaciers in Dronning Maud Land, Antarctica.

Methods: After gathering the data from the WorldView satellites, the glacial landforms were identified and digitized using the ESRI ArcGIS© software. Following this, two field work sessions were carried out in accessible parts of the Heimefrontfjella, Ahlmannryggen and Borgmassivet ranges. In these sessions, the previous mappings were checked for accuracy and more details, such as specific locations, and landforms, were recorded. The last step in creating a clear presentation of the area map was to transcribe the sensor bands from the WorldView. The sensor bands are data from WorldView that correspond to certain wavelengths and resolutions. These wavelengths and resolutions provide information on surface textures, materials, and sediments. 

This figure shows the mapping of a glacier in Grunehogna. It shows how detailed and high definition the Worldview mapping techniques on glaciers are. (a) shows the far-out view of where (c) and (d) are on the one glacier. (b) points out the specific features of (a). (c) and (d) identifies the texture of parts of the glacier, including patterned ground and debris.

Results: With the images collected, ten different landforms were able to be clearly identified. These ten landforms are: windscoops, crevasses, longitudinal surface structures, blue ice areas, boulders, striations, cirques (semi-circular depressions), supraglacial debris, sediment cover and patterned ground. The identification of these landforms helps glaciologists discover the effects and patterns of climate change. For example, windscoops, are concave hollows in the ice and are used to provide information on wind and slope directions. Another landform that is important to study and is now able to be analyzed is crevasses. Crevasses are cracks in the ice surface that are dangerous to step on when field teams are out on the ice. With the WorldView mappings, these locations of these crevasses are identified, which provides more safety for the team.

Why is this study important? This article shows how important updates in technology can bring in the ability to identify the physical features of Antarctic glaciers. With WorldView satellites, clearer pictures of the glaciers can be taken. This leads to more accurate data for glaciologists to determine glacial shape and features present.

The big picture: One of the greatest effects of climate change occurring in modern time is the melting of the world’s glaciers. It is important to keep mapping the glaciers and ice sheets to assess their gradual changes due to climate change. With these technologically advanced systems, glaciologists are able to analyze the ice sheets and glaciers with greater detail than ever before. 

Citation: J. C. H. Newall, T. Dymova, E. Serra, R. Blomdin, O. Fredin, N. F. Glasser, Y. Suganuma, J. M. Harbor & A. P. Stroeven (2020) “The glacial geomorphology of western Dronning Maud Land, Antarctica”, Journal of Maps, 16:2, 468-478, doi: 10.1080/17445647.2020.1761464

Discovery of new Cretaceous Beetles could uncover new paleoecological interactions in Cretaceous forests

Coleoptera in amber from Cretaceous resiniferous forests

By: David Peris

Summarized by: Austin Spencer

Bio:  Austin Spencer is a geology major at the University of South Florida and is currently a senior. Once he earns his degree, he plans to work for the Florida Department of Environmental Protection with the Florida Geological Survey and eventually would like to work at a community college teaching an introductory geology class to help teach a new generation of potential geologists. When he is not studying geology, he enjoys reading, hiking, and cycling in his free time.

What data were used? Beetle fossils discovered in Cretaceous-age amber from around the world. The age and location of these Cretaceous amber deposits are shown in Figure 1 on the stratigraphic chart of the Cretaceous. It is important to point out that no new materials from Myanmar were collected for this study. Paleontological associations have come together against buying and collecting fossils from Myanmar due to the human rights violations that are occurring in the country. You can read more here: Statement from the Society of Vertebrate Paleontology

Figure 1: Stratigraphic Chart of the Cretaceous period and the ages and locations of Cretaceous amber deposits containing beetle fossils.

Methods: This study used a digital microscope to create up close images of fossil beetles in amber, as well as information from other scientific papers to create a taxonomic list of new beetle species found in various deposits of Cretaceous amber up to 2019. The taxonomic list can be found in the papers Appendix A.

Results: Coleoptera is an order that contains all species of beetles. This study highlights newly discovered species of coleoptera that are preserved in amber, which is fossilized tree sap, from the Cretaceous Period (~129-66 Ma). This study has revealed that there have been 364 new species discovered from Cretaceous-age amber. When an insect is preserved in amber, it is often preserved in great detail. This allows researchers to study the beetles as they were millions of years ago. This has led to ecological discoveries found from these new fossils. Some of the fossils discovered have shown a feeding structure called a spore brush, which is used to eat spores from fungi. These spore brushes have been observed in some modern mycophagous beetles, which are fungal feeding beetles. This discovery shows that fungal feeding beetles have been around since the Cretaceous. Another discovery from the study of Cretaceous fossil beetles is their role as pollinators. Today, bees and butterflies are known as the main pollinators; however, before bees and butterflies evolved to be pollinators, beetles were important insect pollinators. Researchers have found in the fossil record from these Cretaceous beetles that there are patterns of adaptations shown from the Early Cretaceous to modern pollinating beetles. Ancient beetles have also been thought as one of the causes of large-scale resin production from trees that go on the form the Cretaceous amber deposits, however, this has never been proven. The study uses an example from a beetle known as an ambrosia beetle, from Miocene Epoch (~23-5 Ma). These beetles are known to bore into wood and deposit ambrosia fungus into the wood, which they use as a food source. These beetles are known to be abundant in Miocene-age amber, which leads researchers to believe that beetles could be the cause of damage to resin-producing trees in other time periods as well. 

Figure 2: A collection of beetles in Cretaceous-age amber. A represents an adult male of Cretaretes minimus . B represents an adult Lymexyildae specimen and C represents an adult Elateroidea specimen.

Why is the study important? Coleoptera includes more than 400,000 species of beetles, which makes up about 25% of all living organisms. Beetles are important organisms for many different ecological interactions around the world. Beetles are pollinators, decomposers, and primary consumers. Since beetles are such an important part of ecosystems it is important that we understand the evolution of these organisms throughout history and how they interacted with past ecosystems to get a better understanding of modern beetles and their importance.

The big picture: This study highlights the abundance of beetles found recently in Cretaceous amber. With the discovery of these new species more research can be done to better understand how these organisms interacted with Cretaceous ecosystems as well as the evolution of beetles to modern day, though it is important to ensure ethical collection of amber fossils. This study will hopefully lead to new discoveries of Coleoptera and their supposed involvement in resin production in Cretaceous forests as well. 

Citation: Peris, D., Coleoptera in amber from Cretaceous resiniferous forests, Cretaceous Research Vol. 113 (2020), https://doi.org/10.1016/j.cretres.2020.104484 

How Long was Venus Potentially Habitable and What Caused it to Become the Volcanic and Acidic Planet it is Today?

Venusian Habitable Climate Scenarios: Modeling Venus Through Time and Applications to Slowly Rotating Venus‐Like Exoplanets

by: M.J. Way, Anthony D. Del Genio 

Summarized by: Lisette Melendez

What data were used? Nowadays, Venus is known for its extreme climate. It’s the hottest planet in our Solar System (with a surface temperature of about 840°F!), and the only planet that spins in the opposite direction. In fact, Venus spins so fast that its acidic clouds can travel completely around the planet in 5 days. Despite its extremities, Venus is also known as Earth’s sister planet. Both planets formed very close to one another and their shape and mass are very similar. So how did their surfaces become so distinct from one another? There are many hypotheses posed as to what early Venus looked like, ranging from a stable world with surface liquid water, to a volcanic world with a magma ocean and a carbon dioxide atmosphere. In order to better understand the early history of Venus, scientists used the data that we have about early Earth and simulations generated by various satellites orbiting Venus.

Methods: By modeling early Venus to closely match the conditions of early Earth using NASA’s ROCKE-3D (a tool you can try out yourself!) general circulation models, the scientists were able to examine how changes in factors like surface water and rotation rate affected Venus’s climate.

Results: The team discovered that Venus’s climate may have been stable and temperate with liquid water at its surface for most of the planet’s history, as shown in Figure 2. So, what caused the huge change? The authors argue that it was caused by the synchronized eruption of massive volcanoes, leading to the large igneous provinces (LIPs, or large collection of volcanic rocks) seen on Venus today. These LIPs could have triggered a runaway greenhouse effect on Venus, a situation where a planet absorbs more energy from the sun than it can radiate back into space. This leads to an inability to cool down and to the evaporation of surface water on the planet. On Earth, some LIPs are known to coincide with mass extinctions, so these events are already known to create colossal changes on the surface of a planet.

Figure 1: An image of the harsh surface of Venus, the most volcanic planet in our Solar System. Credit: NASA JPL.

Why is this study important? This study is important because it gives us insight as to whether early Venus ever had life-friendly environments: did the planet ever experience the same evolutionary processes that Earth did? It also helps us understand exoplanets, which are planets outside of our Solar System, which are tens of thousands of years away by rocket travel. Some of these rocky exoplanets orbit very close to their host stars, much like Venus orbits close to the Sun. So, perhaps these exoplanets host surface liquid water as well!

Figure 2: A graphical representation of the possible climate history of Venus. For most of its history, it is proposed that Venus had a temperate climate with surface water.

The big picture: After analyzing the various models of Venusian history, scientists found that Venus was potentially habitable, like Earth is, for most of its lifetime, which is remarkably different from the acidic, scorching atmosphere we observe today. Large, simultaneous volcanic eruptions may have made it impossible for Venus to cool down, and the resultant dry and hot atmosphere could have led Venus to its current conditions. Even so, more observations from Venus’s surface are needed to fully understand its history and transformation.

Citation: Way, M. J. & Genio, A. D. D. Venusian Habitable Climate Scenarios: Modeling Venus Through Time and Applications to Slowly Rotating Venus-Like Exoplanets. Journal of Geophysical Research: Planets 125, e2019JE006276 (2020).

 

Ordovician paleontology in Australia and its global significance

Ordovician strata in the Cliefden Caves area, New South Wales: a case study in the preservation of a globally significant paleontological site

By I. G. Percival, B. D. Webby, and H. D. T. Burkitt

Summarized by Joseph Stump. Joseph Stump is an undergraduate geology major at the University of South Florida. After graduating high school in Sebring, Florida in 2004, Joseph was unsure about which career he wanted to pursue, making college difficult without an end goal to strive towards. In 2006 he enlisted in the United States Army as an airborne Satellite Communications Operator and Maintainer. Staff Sergeant Stump received an honorable discharge from the Army in 2016 and has been using the Post 9/11 GI Bill to earn his degree since then. Thus far, he has completed an Associates in Arts in Engineering from Hillsborough Community College and is currently in his final year of obtaining his B.S. in Geology, with a minor in Geographical Information System Technology. Joseph is set to graduate in Summer 2020. Upon graduation, he would like to pursue a career studying/monitoring/managing Florida’s water resources and coastal habitats.

Methods: The article utilized data gathered from at least 60 published scientific papers and nearly 300 species of fossils (including calcisponge stromatoporoids, sponges, corals, trilobites, nautiloids, conodonts, brachiopods, radiolarians, and cyanobacteria (‘algae’)) within the Cliefden Caves area of New South Wales, Australia, with several of these being endemic (localized) to this area, to support its significance for preservation of global significance. The main threat to this area, and the need for the preservation, is the proposed construction of a dam, which would result in the flooding and destruction of valuable scientific lands and the fossils within it. 

Results: The fossils contained within the rocks of this area include the world’s oldest known brachiopod shell beds. Brachiopod shells are excellent zone fossils, meaning they can help reconstruct the environment by the shape of their shells. Brachiopods are generally zoned by sediment grain size relationships of their shell shapes; meaning, certain species of brachiopods seem to correlate with different sizes of grains (i.e., different environments). Also present are the earliest indisputable rugose corals found anywhere on Earth, an extinct type of coral. If the proposed dam construction is approved in this area, one of the most diverse deep-water sponge faunas ever recorded is in jeopardy of being destroyed and lost from the fossil record forever. The authors of this article all agree that, despite the significant research already done on the area by scientists, there is more to be discovered in the area that holds truths to the history of life on Earth.

A Belubula shell bed from Cliefden Caves; this specific type only occurs in this locality, so far as scientists know. These brachiopods are preserved mostly articulated (both shells together) and in situ (in place where they originally lived on the sediment). Scale bar is a Australian 50 cent coin (32mm diameter)

Why is this study important? This area is important to study due to its ability to better understand the Earth’s geologic and paleontological history. During the Ordovician, the oldest complete vertebrate fossils can be found, and this is where plant life began to migrate onto land, with animals soon to follow. It is also important to understand the climate of Earth during this time frame, as it exploded with diversity (i.e., the Ordovician Radiation), but it ended with what some consider the second largest extinction in Earth’s biological record. Some argue that this extinction was not ecologically major; however, the best way to understand these events and uncover the facts is to study the geologic and paleontological evidence left behind (where available). The issue with studying the geology/paleontology of the Ordovician is the lack of availability of fossil evidence relative to other periods. The end of the Ordovician is marked by glaciation. When a glaciation occurs, oceanic water regresses (moves away from land) and when the glaciers melt, the ocean transgresses (moves towards land). The problem is that these dynamic ocean conditions causes major erosion of any sediments/fossils deposited and often deletes them from the geologic record as an unconformity (“missing time” in a sample of sediments). The flooding that will result from constructing a dam in the region will have the same history erasing effects on the paleo environment as the ancient sea-level changes.

The Big Picture: Human population growth requires a higher demand on water and electricity; however, the current plans of placing a dam in the Cliefden Caves area of New South Wales will have significant negative impacts on the availability of current geologic and paleontological important rocks. A universal fact of life is that if history is not learned from, it is doomed to be repeated. Current global conditions are trending towards a climate that is uninhabitable by the human species. The significance of understanding these events is that measures could possibly be put into effect to mitigate or prevent global cataclysm of anthropogenic causation. Although geological and paleontological research does not often go synonymous with saving lives, the discoveries from their research can potentially impact the longevity of our species and others’.

Citation: Percival, I.G., Webby, B.D., and Burkitt, H. D. T. “Ordovician strata in the Cliefden Caves area, New South Wales: a case study in the preservation of a globally significant paleontological site.” Australian Journal of Earth Sciences, 2019. https://doi.org/10.1080/08120099.2019.1574271

 

Will NASA’s Dragonfly Mission Encounter Dust Devils on Titan?

Dust Devils on Titan

Brian Jackson, Ralph D. Lorenz, Jason W. Barnes, and Michelle Szurgot

Summarized by Lisette Melendez

What data were used? In 2019, NASA announced a brand-new mission: Dragonfly. The objective? To visit Titan, the largest moon of Saturn and the only place in our universe (besides Earth) where distinct evidence of surface liquid has been discovered. Titan’s environment is very similar to that of very early Earth, with a nitrogen-rich atmosphere and volcanic activity. By studying Titan’s chemistry, scientists can discover more about the origin of life itself. It’s a very exciting mission, but it’s important for scientists to prepare for all the different obstacles the rotorcraft will encounter on Titan’s surface, including hazardous weather phenomena like dust devils.

An illustration of NASA’s Dragonfly rotorcraft-lander approaching the dunes on Saturn’s exotic moon: Titan. Credits: NASA/JHU-APL

We’ve learned more about weather patterns on Titan through NASA’s Cassini spacecraft, which orbited Saturn from 2004 to 2017. This study focuses on how dust storms are identified on other celestial bodies and what implications they hold for the Dragonfly mission. Cassini identified three regional dust storms within the equator near the “Shangri-La” dune fields that were chosen as Dragonfly’s landing spot. The study of these dust storms in Titan’s unique environment (with clouds and rain of methane!) can help us learn more about how they operate and life dust in the first place. This study also draws from observations by the Huygens probe for information on Titan’s temperatures and atmosphere.

Methods: In order to determine the weather conditions necessary for a dust storm on Titan, scientists need data on various atmospheric circumstances, such as temperature, elevation, and pressure. By analyzing the images and observations collected by Cassini and Huygens and combining these findings with data collected by observing dust devils here on Earth, scientists were able to model the surface conditions that were suitable for dust devil formation as well as the size of these storms. The study focused on dust devils on the equator because that’s where we have the most data available about Titan’s weather conditions.

An illustration of the Cassini-Huygens space-research mission, which was a collaboration between NASA, the European Space Agency (ESA), and the Italian Space Agency (ISA) to study Saturn and its many moons. Credit: NASA/JPL

Results: Many of the atmosphere conditions identified on Titan are favorable for the formation of dust devils. On Earth, dust devils are generally hindered by the presence of liquid because the increased particle cohesion (i.e., how sticky the particles are to one another) prevents wind from being able to lift the dust particles. Observations show that the equator of Titan is very arid and dry, with methane downpours only occurring in areas once every 10 Earth years. By looking at surface humidity levels measured by Huygens, it shows that the surface is too dry for even cloud formation. The abundance of dunes and dust storms provides further evidence that Titan has the ideal environment for dust devils.

An image of a dust devil in Kansas. Credit: The Thunderbolts Project

However, there are some surface conditions on Titan that may reduce the occurrence of dust devils, including the possibility of insufficient wind speeds. Additional work is required to model typical speeds on Titan’s surface.

Why is this study important? This study is important because it helps predict the occurrence of dust devils on Titan when Dragonfly is scheduled to arrive in 2034. This study outlines what remains unknown about the formation of dust devils and how Dragonfly presents the opportunity to study wind-related phenomena in a novel environment.

The big picture: After analyzing the environment on the surface of Titan based on the data currently available, it is concluded that the dust devils will most likely not pose a threat to the Dragonfly rovercraft (since they are too slow in the given conditions). Nevertheless, the mission can provide crucial insight to the creation of dust devils and how frequently they occur on other celestial bodies. Dragonfly provides us the opportunity to learn so much more about extraterrestrial worlds, and we’re all very excited for its departure!

Citation: Jackson, B., Lorenz, R. D., Barnes, J.W., & Szurgot, M. (2020). Dust devils on Titan. Journal of Geophysical Research: Planets, 125, e2019JE006238. https://doi.org/10.1029/2019JE006238

Climate Change and Encephalitis

The potential impact of climate change on the transmission risk of tick-borne encephalitis in Hungary

Kyeongah Nah, Ákos Bede-Fazekas, Attila János Trájer, and Jianhong Wu

Summarized by Kailey McCain

What data were used? The data collected for this study includes the monthly average temperature values in Hungary from the years 1961-1990. Specifically, for the past climate data,researchers used the CarpatClim-Hu database. For future climate predictions, the researchers used two distinct climate models: ALADIN-Climate 4.5 and RegCM 3.1. Additionally, previously established models for Tick-borne Encephalitis virus (i.e., a human viral infectious disease) transmission was used. Models help us hypothesize how different scenarios will look, by allowing us to input a lot of different types of data to understand large future patterns, like the one in this article! 

Methodology: By using the previous climate data for the years 1961-1990, the researchers established a predictive warming model for the years 2021-2050 and 2071-2100 in Hungary. This data was then compared to the tick-borne encephalitis virus (TBEV) transmission model to establish correlations between the data sets. This model broke down the transmission into various factors: reproduction numbers, duration of infestation, and density. The dynamics of transmission can be visualized in figure 1.

Figure 1: This figure shows an extensive diagram of how an infected tick spreads the disease to humans, livestock, and other animals. The inner circle represents the stages from larva, to nymph, to mature tick; then it branches to external transmission.

Results: The predictive climate model showed a steady increase in temperature for the age ranges 2021-2050 and 2071-2100, and the TBEV model resulted in an increase in tick population and transmission. These increases can be positively correlated (linked) to warming climate because previous data shows that a higher temperature speeds up the rate of sexual maturity in ticks; meaning, this allows the tick to reproduce at an increased rate. Moreover, research has shown that a warming climate leads to the elongation of tick questing season; which increases the chance for transmission. When a tick is questing (shown in figure 2), it is strategically placed on vegetation in order to grab a hold of by passers. 

Figure 2: This image represents a questing tick sitting on the edge of a lead with their legs spread out, and ready for attachment.

Why is this study important? This study is important because it shows the dynamic effects climate change has on global health. It also conveys an important message that the prevention of climate change is not only a biological and geological problem, but a public health problem, too. This means that solutions for reducing the impacts of climate change have to be creative and have to be from a lot of different types of researchers! 

The big picture: This study helps us understand the ways in which infectious diseases, (e.g., Tick-Borne Encephalitis Virus) are affected by climate change. As well as giving a glimpse into the future of what disease transmission will look like if prevention protocols are not put in place.

Citation: Kyeongah Nah, Ákos Bede-Fazekas, Attila János Trájer, & Jianhong Wu. (2020). The potential impact of climate change on the transmission risk of tick-borne encephalitis in Hungary. BMC Infectious Diseases, 20(1), 1–10. https://doi.org/10.1186/s12879-019-4734-4

The projected timing of abrupt ecological disruption from climate change

The projected timing of abrupt ecological disruption from climate change

Christopher H. Trisos, Cory Merow & Alex L. Pigot

Summarized by Shaina Sadai

What data were used? The data used is a combination of climate model output and ecological data for 30,652 marine and terrestrial species. For each species they determine the climate conditions and spatial extents that a species is known to have existed in throughout history. The climate model output that was used were temperature and precipitation data from 22 different models and 3 emissions scenarios (RCP2.6, 4.5, 8.5).

Methods: The authors created species assemblages contained in 100km^2 grid cells. Using these they generated ‘horizon profiles’ which give the percentage species within each assemblage that would experience climate conditions exceeding those of their historic limits at a given time. They cross referenced when each species would be living for more than 5 years straight in an area where the temperature exceeded the maximum temperature they have been known to exist at through their history in order to quantify when a species crossed their ecological limit. By repeating this method across the planet they were able to construct horizon profiles at many locations, including sensitive ecosystems such as the Amazon Basin and Gobi Desert.

Results: One of the most striking results is how abrupt impacts to biodiversity could be. The profiles show that an average of over 70% of species in a given assemblage were exposed to conditions exceeding their limits within a single decade, regardless of climate model of emissions scenario. This was in part due to the species within a region evolving for similar temperature ranges. The abruptness of when ecological limits were breached was even higher for marine ecosystems than terrestrial ones. Tropical species are particularly vulnerable to having a higher percentage of species exposed to dangerous temperatures by the end of the century because they already exist in places where they are close to their temperature limits. Polar species were also highly vulnerable due to the rapid rate of changes occurring in these regions.

Under higher emissions scenarios (RCP8.5) temperature thresholds are exceeded sooner with some occurring even before 2030. The most vulnerable regions were the Amazon, Indian subcontinent, and Indo-Pacific regions where by 2100 over 90% of species in any assemblage were exposed to temperatures over their limits. In contrast the low emissions scenario (RCP2.6) delays the point at which vulnerable species are at risk by 60 years. If warming by the end of the century is kept below 2C only 2% of species assemblages will be exposed to abrupt exposure events.

Why is this study important? This study was able to use a combination of data on species’ ecological limits and climate model data to give a robust picture of when and where species assemblages may cross safe limits. It shows the potential for abrupt loss, particularly of biodiverse ecosystems, and can help inform policy efforts and future research needed to assess risk.  If emissions are decreased and the rate of temperature increase is slower it gives species more time to adapt.

The big picture: We must prepare for significant impacts to ecosystems and biodiversity under a changing climate, and take steps to prevent serious ecological harm. Yet again we see that early mitigation is crucial to mitigate harm.

Citation:
Trisos, C.H., Merow, C. & Pigot, A.L. The projected timing of abrupt ecological disruption from climate change. Nature 580, 496–501 (2020). https://doi.org/10.1038/s41586-020-2189-9