Undergraduate Student

New Dataset of Global Evaporative Water Loss

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Evaporative water loss of 1.42 million global lakes

Gang Zhao, Yao Li, Liming Zhou and Huilin Gao

Summarized by Michael Hallinan 

What data was used?  A series of geospatial data containing information on global lakes that are over 0.1 square kilometers (approximately 328 square feet) was sourced from HydroLAKES, a database centered around mapping the global freshwater. The data included a total of 1,427,688 water bodies, of which 6715 are reservoirs. In addition to this, three sets of meteorological data from TerraClimate, ERA5, and GLDAS were used to cancel bias as each dataset was developed independently through different institutes with a wide range of input sources. Lastly, a series of lake ice coverage and lake evaporation data were obtained from the Natural Snow and Ice Data Center and previous studies, respectively. 

Methods: Using the geospatial data on lakes, a series of calculations was performed to estimate potential water loss due to evaporation of lakes and reservoirs. This was performed through calculating the change in heat stored by the body of water using the density, specific heat of water, water depth, and change in water temperature. Then an estimation of lake evaporation rate was performed using vapor pressure, net radiation, change in heat, surface area, as well as wind and other environmental data. In addition to this, further data processing occurred to account for ice coverage as well as to remove biases in satellite-sourced data caused by cloud coverage.  

Results: This study created a dataset of evaporative water loss from 1958 to 2018 containing estimates of monthly evaporative loss of over 1.42 million lakes world wide. The most notable observations of this dataset are that the long-term average global lake evaporation has increased by 3.12 cubic kilometers per year in volume (roughly 0.75 cubic miles) while the average currently is 1500±150 cubic kilometers (roughly 932 cubic miles). This trend is likely a result of three main factors: Around 58% of this increase is a consequence of increased evaporation rate, 23% is caused by decreasing lake ice coverage, and 19% stems from an increase in lake surface area. In addition to this, these three factors have an identifiable pattern in their global distribution. High-latitude and high-altitude regions such as Tibetan Plateau and northern Eurasia show amplified effects of climate change on ice duration and as a result evaporation, likely having accelerated evaporation in the future.

Global map showing a ratio of lake evaporation versus total evapotranspiration (all land evaporation plus plant transpiration, with values ranging from 0% to >30%. Most of the global land surface falls into the 3% to 6% range. Much of Canada as well as some of the western regions of the United States fall into the 6% to 10% range, with some regions of Canada being in the 10% to 18% or even 18% to 30% range. The northern region of South America is predominantly between 0 and 1% while the southern hemisphere is mainly between 3% and 6% with some regions near the upper Andes Mountains having a ratio of 18 to 30%. Africa is a mix with much of the continent varying between 0 to 1% and 3 to 6% with some of the southern and north-eastern regions having ratios between 6 to 10% and even >30% near Egypt. This is globally the area with the highest ratio. Eurasia is mainly between the 0 to 1% and 1 to 3% categories with the exception of Iraq and Iran with that region having 6 to10% up to 18 to 30% ratios appear. InFinland, Europe also begins to see this same ratio increase to 6 to 10% and 10 to 18%. Lastly, Oceania is a mix of 1 to 3% and 0 to 1% with the 0 to 1% occurring on the eastern side of Australia and the majority of the island nations.
Global map showing percentage ratio of lake evaporation versus total evapotranspiration (all land evaporation plus plant transpiration).

Why is this study important? This dataset is essential to understanding global evaporative loss and the response of bodies of water to global warming. This dataset is the first of its kind to provide long-term monthly evaporation data on a global scale. This information can be used in the context of water availability estimations as well as in climate models. Although previous studies about water evaporation have been performed, many of them focused on only a few environmental parameters such as lake surface temperature, lake and river ice, or other attributes. This knowledge will be imperative in improving our overall understanding of the effects of lake evaporation

The big picture: A dataset of evaporation data comprising 1.42 million lakes from 1958 to 2018 was formed through a mixture of geospatial, meteorological, and lake ice coverage data. This dataset is the first of its kind and can be used to better understand water availability as well as water bodies’ reaction to climate change. Lastly, through this dataset it was discovered that there is an increase in water evaporation of about 3.12 cubic kilometers per year in volume (roughly 0.75 cubic miles).

Citation: Zhao, G., Li, Y., Zhou, L. et al. Evaporative water loss of 1.42 million global lakes. Nat Commun 13, 3686 (2022). https://doi.org/10.1038/s41467-022-31125-6

Climate Change Threatens Salmon Habitats within the US

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Climate Change Shrinks and Fragments Salmon Habitats in a Snow-Dependent Region

Daniele Tonina, James A. McKean, Daniel Isaak, Rohan M. Benjankar, Chunling Tang, Qiuwen Chen

Summarized by Michael Hallinan

What data was used? The EAARL (Experimental Advanced Airborne Research Lidar) was used to collect the majority of the data. This machine rapidly outputs green lasers through air as well as water, which collects location and elevation when the reflection of each laser pulse is detected. This machine was used to survey Bear Valley Creek, an essential Chinook salmon (Oncorhynchus tshawytscha) spawn point located in Idaho, U.S.A. In addition to this, a series of habitat suitability curves (data expressing the ability of a species to live on observed environmental conditions) from the Washington Department of Fish and Wildlife was also used.

Methods: The location and elevation data allowed the local topography to be mapped. A series of hydrologic models and climate models were applied to the region with this topographical data, allowing the researchers to calculate surface area, volume, and mean depth of nearby bodies of water which are essential for early salmon development. In addition to this, hydraulic data such as velocity of water, depth, and shear stress (stress from water moving downstream) was predicted using these models for the entire year. All the modeled hydrologic, topographic, and geologic data were compared to the habitat suitability curves allowing to predict the quality of potential habitats in regards to salmon sustainability and upbringing as well as the distribution and connectivity of these habitats for salmon. 

Results: Between 1957-2016 it was found that average water flow has declined by 19%, or about 3% per decade. High water flow is essential for salmon to migrate in and out of streams. In addition, the velocity of the water also showed a decrease of 17% with the largest drops occurring in areas where salmon spawning is most frequent. As a result of these changes in water movement throughout these streams, there also was a clear negative impact on habitat conditions. It was found that the suitable spawning area for the salmon has significantly decreased. It’s expected that future summer water flow will be 72% lower than previously which will result in an approximate 38% decrease in spawning habitat size. Overall, climate change has shown to generate more negative conditions for salmon spawning as well as future negative impacts on habitat distribution. This can potentially threaten the long-term health of Chinook Salmon within this region, especially as they are already challenged by overfishing, these conditions could permanently damage the population’s health.

A colored figure displaying spawning habitat quality distribution for chinook salmon when water flow is at 1 cubic meter per second. Values go from 0 to 1 with 1 being the highest quality and 0 being the lowest. The river meanders in a snake-like shape going from the north-eastern part of the map to the south-eastern part of the map. Much of the water near the banks of the river features a spawning quality of 0, detailed in red. However, the more central parts of the river bed tend to fall within the 0.5 to 0.6 range with irregularly distributed sections within the 0.9 - 1 range throughout the river. This means that spawning habitat quality is generally very low near the edge of the river and mediocre through much of the river with higher quality occurring only in the center.
Figure displays an approximately 0.5km long segment of the Bear Valley Creek. distribution of Chinook salmon spawning habitat quality when water flow is at 1 cubic meter per second. The higher the quality value the more favorable to spawning, the lower the value the less favorable for spawning.

Why is this study important? Climate change has been shown to pervasively affect life on earth for example by changes in temperatures. Although within recent decades more progress has been made on our understanding of the topic, much of the current research still focuses on stream water temperature while other hydrological conditions that may significantly impact species health remain understudied. This study looks at these deeper hydrological conditions within the northwestern U.S, specifically in the Bear Creek region of Idaho, which is essential for the larger salmon population across the country and the fishing industry that depends on them. By increasing our understanding of these conditions and the impact of climate change, we can react better and begin to remediate these changes to support salmon populations as well as the local and global economies that depend on them. 

The big picture: Climate change has negatively affected salmon health and populations within the Bear Creek region of Idaho, U.S.A. This has been identified previously, but is usually only looked at within the context of temperature changes. This study further explores hydrological data and how it affects salmon reproduction, such as flow, velocity, and water depth. A 10% decrease in suitable spawning spaces was identified when comparing the likelihood of use as well as a 17% drop in flow velocity which negatively influences migration among stream for salmon. All of these factors threaten salmon populations, however being able to identify these may allow us to better understand salmon health as well as how to react in terms of conservation.

Citation: Tonina, D., McKean, J. A., Isaak, D., Benjankar, R. M., Tang, C., & Chen, Q. (2022). Climate change shrinks and fragments salmon habitats in a snow‐dependent region. Geophysical Research Letters, 49(12). https://doi.org/10.1029/2022gl098552 

Early Risers – A Study of Early Tetrapod Locomotion

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Locomotory Behaviour of Early Tetrapods from Blue Beach, Nova Scotia, revealed by microanatomical analysis

Kendra I. Lennie, Sarah L. Manske, Chris F. Mansky and Jason S. Anderson

Summarized by Makayla Palm

What data were used?  Previous research has analyzed possible moving mechanics for the first tetrapods that lived on land (i.e., a four-limbed vertebrate), but most of the conclusions were made in inference, like by analyzing footprints. The researchers of this study aimed to find more direct evidence of how these early reptiles like Tiktaalik or Ichyostega moved in order to determine what lifestyles new fossils from Blue Beach, Nova Scotia had (aquatic/land). In order to test their hypothesis, they studied the limb bones of the new fossils and living creatures like cats and platypi in order to observe how these limb bones adapted to the stresses of gravity and hitting solid ground. The scientists used 3D scans of bones from both the modern and the fossil tetrapods; the living ones had a range of lifestyles from aquatic to terrestrial, for better comparison to the fossils.

Methods: The researchers took 3D scans and measured the volume of limb bones from eight extant (or living species) and five extinct species (the fossils from Blue Beach, Nova Scotia). This information would give them the ability to tell how, or if, these creatures walked. The extant species were studied in order to observe how and where muscles were stressed during walking (and what clues that left behind in bone) in living creatures to find what patterns to look for in the fossil specimens; this created what is called a compactness profile. The compactness profile summarizes how the different tissues in the bones react to stress over time by observing the amount of trabecular tissue in a certain part of the limb bone. Trabecular bone is a kind of bone tissue that is made of tiny plates meshed together. The trabecular tissue arranges itself where the bone experiences the most stress; this is the pattern being observed in the compactness profile. The bones from each specimen were digitally sliced in a cross-section to observe the internally visible trabecular bone. The researchers observed the trabecular bone in extant species first because their moving mechanics are known. Once they established the pattern of where the trabecular bone was in extant species, they applied it to the extinct species to determine their moving mechanics.  

Results: The trabecular bone’s location shows where the most stress is being absorbed in the bones (think of swimming and the different muscle groups used in contrast to walking- a long walk and a long swim will leave one sore in different ways.) The study shows different stress in the trabecular bone across taxa, depending on if the creature was aquatic or land-living. They concluded that the aquatic species had trabecular bone in the midshaft, or middle of the bone because they would pump their legs while swimming. Terrestrial, or land-based tetrapods, had trabecular bone around the two ends of their femurs, indicating they walked. Some of the fossil tetrapods had less dense trabecular bone than some of the extant species, but it was at the ends of the limb bone; researchers concluded these fossils would have lived a semi-aquatic life (a modern alligator is semi-aquatic, for example). Based on the results of this study, it is likely that the Blue Beach tetrapods represented a range of different lifestyles, from fully aquatic, and semi-aquatic, to fully terrestrial, as all of the patterns of trabecular bone described above were found in the different taxa. 

Twelve cross-section samples of limb bones from different species and different lifestyles are shown with the trabecular bone visible. The figure shows the semi-aquatic genera first, the Blue Beach fossils second, and the terrestrial genera last. The cross sections of terrestrial creatures have a black ring with a white center, such as Felix, Uromastyx, and Eublepharis. Semiaquatic creatures have a thinner black ring with 50% white center and 50% gray center indicating some trabecular bone presence. These creatures are the Amblyrhynchus and Ornithorhynchus genera. Aquatic creatures have an almost completely full center, indicating a significant amount of trabecular bone. The aquatic control sample was from an Ornithorhynchus. The figure also has a graph showing the levels of compactness throughout the sample. Samples with more trabecular bone have a more consistent compactness level, whereas less trabecular bone has a steeper graph. The steeper graph is reflective of the absence of trabecular tissue.
All cross sections of the femurs from this study are shown here, along with a graph showing compactness profiles, which is similar to density. Since the specimens come from different environments and lifestyles, there is an expected difference in the cross-section density. These cross-sections come from the midshaft of the limb bones, so creatures with semi-aquatic or fully aquatic lifestyles should have trabecular bone in their cross sections. Those with terrestrial lifestyles should not. For example, the feline (Felix) cross section in the bottom right corner has an open circle in the center of its cross-section, indicating no trabecular bone, which is consistent with its terrestrial lifestyle. In contrast, the Ornithorhynchus (the modern-day platypus) cross section has a lighter amount of trabecular bone, which is consistent with its semi-aquatic lifestyle.

Why is this study important? The study of tetrapod locomotion, or movement mechanics, reveals how the earliest known walking creatures lived and moved. Previous research used proposed ideas on locomotion by inferring muscle and ligament placement on the limb bones of the tetrapods. This study uses direct evidence by looking at how the limb bones react to stress to determine how these creatures moved in various environments. 

The big picture  Researchers are using tissue evidence in order to better understand how the earliest walking tetrapods walked. The tissue, or trabecular bone, helps researchers see direct evidence of walking, rather than relying on inferred information about soft tissues. The analysis of trabecular bone is direct evidence for locomotion because it is re-arranged by stresses from gravity. The ability to observe these changes in soft tissue depending on lifestyle is a definitive classification of lifestyle for these early risers. Rather than saying “these creatures had the ability to walk”, the researchers are saying, “these creatures did walk.”

Article Citation: Lennie, K. I., Manske, S. L., Mansky, C. F., & Anderson, J. S. (2021). Locomotory behaviour of early tetrapods from Blue Beach, Nova Scotia, revealed by novel microanatomical analysis. Royal Society open science, 8(5), 210281.

How Mushrooms Could Help Clean Up Pollution

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Mycoremediation of heavy metals: processes, mechanism and affecting factors

Vinay Kumar and Shiv Kumar Dwivedi

Summarized by Anna Geldert

What data were used? In this review, researchers assessed data from over 300 previous studies on mycoremediation, a process which uses fungi to remove pollutants such as heavy metals from the environment. These studies included findings on the mycoremediation potential of 62 living species of fungi, and 21 dead species. In total, the review considered 11 types of heavy metal pollutants (mercury, cadmium, lead, chromium, copper, arsenic, manganese, nickel, cobalt, zinc and iron) as well as data on drinking water standards, and health impacts of each heavy metal from the World Health Organization (WHO).

Methods: The goal of this review was to synthesize data from existing research, and to identify which factors most affect fungi mycoremediation potential. The authors looked for trends and patterns from previous studies, and summarized findings related to the health impacts of heavy metal exposure to fungal species, as well as the biological, chemical, and physical processes that are used for the absorption of pollutants. They also identified the most important factors affecting the rate of absorption for both living fungi and dead fungal biomass. 

Results: In general, results demonstrate that both heavy metal tolerance and absorption potential differs greatly among species of fungi. Species belonging to the class ascomycete were found to tolerate higher concentrations of heavy metal pollutants, though the explanation for this is still unclear. Both living and dead fungal biomasses were able to absorb heavy metals through a variety of biological processes in the cell wall, and this absorption may be increased further through physical and chemical treatments. In regard to factors that impact absorption rate, the review found that lower pH levels, high agitation (water disturbance) rates, and low flow rates all consistently increased the absorption rate of tested fungi. Factors such as temperature, time, and heavy metal concentration varied based on the species of fungi. Lastly, this study concludes that dead fungal biomass will most likely work better than living fungi for mycoremediation, since varying pH levels, temperatures, and heavy metal concentrations are not limiting factors as dead fungal masses do not need to be kept alive.

A flow chart which starts at a light pink box titled Mycoremediation of heavy metals, which has two main paths, represented by thin black arrows. From this point of origin on the left is a gray box titled By Growing Fungi. This continues to a pink box on the left titled Genetically modified and across from it on the right is a gray box titled Non-Modified. Non-modified continues the chart on its downward path to two more boxes. The left hand box is light pink labeled Indirect Application which below it in parenthese states “By production of siderophores and secondary metabolites”. Across from the light pink box is a gray one with the label Direct Application. Both Direct and Indirect Application continue the chart downward to two light blue boxes with the titles Specific Action of a single fungus and Synergistic Action of more than one fungi, on the left and right respectively. The chart continues from these two, and again are two boxes both in an orange color. They are titled Immobilized form and Free form. Finally this side of the chart ends with two purple boxes labeled Continuous mode and Batch mode. Returning to the beginning of the chart but on the right side, is a blueish gray box titled By Fungal Biomass. This branches into a light blue box on the left titled Activation and across from it, in the same previous blueish gray color is a box labeled Direct Application. From Activation on the left the chart splits into 3 boxes. On the left is a light pink box titled Physical Activation with parentheses stating “heat, magnetic modified, etc”. In the center is a pink box titled Chemical Activation with parentheses stating “acetone, NaOH, ether, etc”. On the right is a light blue box titled Physico-chemical Activation. All 3 boxes continue the chart to a blue box titled Characterization and Application. This light blue box continues to a final box within the chart, and from the left-hand side the chart converges onto this box. This large gray box titled Factors involve in HMS Remediation process. Below it is a list that states Time, pH of the soln, Temperature, Adsorbent conc, Adsorbent dose, Aggitation rate, Medium composition, and Adsorbent type in descending order.
Fig. 1 Flowchart of mycoremediation in wastewater heavy metal treatment methods, comparing the growth of fungi and fungal biomass.

Why is this study important? This study is useful because it draws conclusions from a large body of existing work on mycoremediation, and recognizes important trends in related findings. This allows for comparisons on the mycoremediation potential of various fungal species, treatment methods, and  treatment conditions, which would be much more difficult without a cohesive summary paper such as this one. This study will enable future researchers, and engineers to create novel and efficient methods for treatment of heavy metal wastewater with fungus. 

The big picture: Pollution is one of several environmental challenges facing our planet today, with heavy metal pollutants being one of the most hazardous, due to its negative impacts on human health. Current methods for treating heavy metal contaminants in wastewater are often not economically or environmentally sustainable. Mycoremediation may provide a sustainable solution to this problem, due to fungi’s inherent ability to absorb environmental pollutants, such as heavy metals. This review provides guidance on what fungal species, treatment methods, and treatment conditions would make this remediation process most effective and efficient. 

Citation: Kumar, V., & Dwivedi, S. K. (2021). Mycoremediation of heavy metals: processes, mechanisms, and affecting factors. Environmental Science and Pollution Research, 28(9), 10375–10412. https://doi.org/10.1007/s11356-020-11491-8

I Like Big Plants and I Cannot Lie – Fruit Size Increases in Absence of MegaHerbivores

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The megaherbivore gap after the non-avian dinosaur extinctions modified trait evolution and diversification of tropical palms

Renske E. Onstein, W. Daniel Kissling, and H. Peter Linder

Summarized by Makayla Palm

What data were used? Qualitative data from modern palm tree fruit, phylogenetic data, and palm tree fossils are used in order to observe changes over time in the taxon Arecaceae, or the palm tree, from the Paleogene Period. After the end-Cretaceous extinction that wiped out the non-avian dinosaurs, mega-herbivores, or any herbivore larger than 1,000 kg ( ~2200 lbs), were nowhere to be found. For the most part, small mammals were left foraging for food, and angiosperms (flower-bearing plants) were able to catch a break. The combination of mammalian seed-spreaders and lack of large herbivores preying on angiosperms (palms in this case) meant that the plants were able to increase in numbers without worrying about defenses. These furry seed-spreaders (small animals that pooped out their seeds) were still spreading, allowing plants to grow and didn’t evolve many defense mechanisms like rough leaves or spines. The researchers hypothesized that they would observe three things about palm diversity in the fossil material from this time: the origin of plant armature (or defense structures like spikes) in the Cretaceous Period because of many large herbivores, the decrease in armature during the Post-Cretaceous Paleogene Megaherbivore Gap (PMHG), and the change in fruit size over time as the plants were able to diversify. 

Methods: Measurements of the palm tree fruit fossil material were taken in order to compare how fruit size changed over time within the megaherbivore gap and observations were made on when these changes in size happened, which supplemented the phylogenetic analysis. Living palms were observed in modern habitats, as were  their interactions with larger herbivores of modern times to better understand how the fossil palms may have interacted with herbivores from the Paleogene.

Results: The hypothesis that the first armature appeared in the Cretaceous was confirmed by fossil material, which indicates an increase in defense likely due to megaherbivores. The armature of plants with larger fruit decreased over time, which also supports the hypothesis of losing these defense structures over time with less predation. Despite the disappearance of megaherbivores in the end-Cretaceous, fruit size stayed relatively large (above 4cm). Plants with larger fruit diversified on a constant scale over time, whereas plants with smaller fruit decreased in diversity, counter to the second hypothesis. Overall, some hypotheses were supported, and some were not. 

The six graphs each have three columns representing before, during and after the Paleocene MegaHerbivore Gap. Graph (a) represents a consistent speciation rate among large fruit (defined to be >4cm in length). Graph (b) represents a speciation of armature in leaves and stems, showing a negative dip during the PMHG with an increase before and after. Graph (c ) represents speciation of stem armature, with a similar pattern to Graph (b), showing a dip during the PMHG. Graph (d) represents the rate of fruit size evolution (from small to large) increasing during the PMHG, and a constant state before and after the gap. Graph (e) represents a transition of evolving armature in leaf and stem, decreasing during the gap and increasing again afterward. Graph (F) represents the evolution of just stem armature, which stays constant before and after the PMHG, but dips significantly during the event itself.
This box and whisker plot tracks the changes of palm trees from before, during, and after the Paleocene MegaHerbivore Gap (PMHG) following the Cretaceous extinction. The median value (middle value of data)is represented by the bar across the yellow box. The graphs show that armature decreases immediately following the extinction ~66mya and the speciation of fruit staying constant. These also show the increased fruit size during the PMGH.

 Why is this study important? A lot of end-Cretaceous Period studies focus on the end of the dinosaurs, what caused the mass extinction, and how the age of mammals began. This study shows a different perspective on a well-studied time period by using a combination of paleobotany and vertebrate paleontology, and observing how the absence of large herbivores affected how ancient palm trees changed ecologically. This documented diversity opened new doors for angiosperm evolution and led to an increase in forests, setting the stage for the next era of geologic time in North America, the Cenozoic. 

The big picture: The Paleogene megaherbivore gap is a time in geologic history where the absence of large herbivores after the non-avian dinosaur extinction greatly affected ecosystems and the change in the landscape to more dense forests. The lack of large herbivores to eat plants allowed plants to evolve fewer defensive structures and larger fruit, which allowed them to spread farther distances and in greater numbers, because of the increase in seeds. 

Article Citation: Onstein, R. E., Kissling, W. D., & Linder, H. P. (2022). The megaherbivore gap after the non-avian dinosaur extinctions modified trait evolution and diversification of tropical palms. Proceedings of the Royal Society B, 289(1972), 20212633.

Surprise Spinosaurid in Southern England…the Biggest in All of Europe??

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A European Giant: a large spinosaurid (Dinosauria, Theropoda) from the Vectis Formation, (Wealden Group, Early Cretaceous) UK. 

Chris T. Barker​,  Jeremy A.F. Lockwood, Darren Naish, Sophie Brown, Amy Hart, Ethan Tulloch, and Neil J. Gostling

Summarized by Makayla Palm

What data were used? Fossil remains of a new theropod dinosaur from Southern England were discovered and excavated over several months’ time. These bones consisted of post-cranial fragments, or the parts of the skeleton below the skull. Most of the vertebrae, parts of the pelvis, and some ribs were identified from this specimen, also known as the White Rock spinosaurid. Measurements were taken of the fragments, and an evolutionary (phylogenetic) analysis was inferred to see where this theropod may fit on an evolutionary tree. 

Methods: Scientists measured these new bone fragments, and over 1,000 characteristics of the fragments were cataloged in a computer and compared to other theropods in a character database. This database categorizes dinosaurs by the features found within their bones, and accounts for the smallest of variations to be as specific as possible. These features also help place the theropod on a family tree by using computer programs that arrange all of the characters to identify which dinosaurs are closely related to one another.  

Results: This theropod’s size and other morphological features indicate that it is likely closely related to Spinosaurus, but may or may not be in the genus Spinosaurus. There is a lot of weathering of the fossil remains, which makes more specific categorization not possible at this time. The presence of canals within the bones suggests that post-death, something began to eat away at the theropod’s bones. Scientists have seen very similar features before in other Cretaceous theropods, and the canals are likely due to beetle pupae that dug their way through these bones after the dinosaur had died. The phylogenetic tree did not provide enough resolution to confirm a more specific group that this specimen belongs to, but the likelihood that it represents a new type of spinosaurid is high. This specimen is not only the first of its kind found in this geological location, but its size rivals all of the known specimens in Europe. 

A black and gray map indicates the size of the Island of Wight, where the spinosaurid in this paper was found and excavated. The Island is just south of England, and is ~50 km in length. The Spinosaurid was found on the northeastern side of the Island near Compton Bay. The closeness of the spinosaurid to the bay could indicate it was a coastal predator.
A geographical map of the Island Of Wight, just off the coast of Southern England. The spinosaurid indicated on the map is where the fossils were found. They are not far from Compton Bay,where the fossil was excavated.

Why is this study important? This study provides insight into the geologic history of Southern England with the presence of the first known large theropod. First, the Lower Cretaceous geological formations of western Europe have been defined as the origin of the spinosaurids. Secondly, the White Rock spinosaurid appears in the fossil record later than any known spinosaurid on the Island, indicating the presence of spinosaurids to last longer than before. The size of this spinosaurid may have warded off other predators, which might explain why fossils of other theropods have been found this late in other known Spinosaurus– bearing locations. This specimen is classified as a spinosaurid and not a Spinosaurus, because its bones were not preserved well enough to confirm a new taxon of Spinosaurus. More phylogenetic analysis, and the discovery of new material, will provide future insight into its taxonomic placement. 

The big picture: A new theropod has been discovered in Southern England, and its large size and location implies it is not only a new spinosaurid, but also one of the largest theropod dinosaurs in Europe to date. Its presence improves the known range of spinosaurids and may provide new insight into taxonomic variation within the spinosaurids. 

Citation: Barker, Chris T.,  Lockwood, Jeremy A.F., Naish, Darren, Brown, Sophie, Hart, Amy, Tulloch, Ethan, Gostling, Neil J.   “A European Giant: A Large Spinosaurid (Dinosauria: Theropoda) from the Vectis Formation (Wealden Group, Early Cretaceous), UK.” PeerJ, vol. 10, 2022, https://doi.org/10.7717/peerj.13543.

The Eastern Kunlun Tectonic Event and How It Intruded in the First Place

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Silurian-Devonian Granites and Associated Intermediate-Mafic Rocks along the Eastern Kunlun Orogen, Western China: Evidence for a Prolonged Post-Collisional Lithospheric Extension

Jinyang Zhang Huanling Lei Changqian Ma Jianwei Li Yuanming Pan 

Summarized by Makayla Palm 

What data were used? The goal of this study was to gain insight into how the Kunlun mountain formation and surrounding area were initially formed. The Kunlun Mountain range primarily has an intermediate and mafic composition, with felsic granite intrusions, or dikes. Dikes are intrusions of magma that cut across previously formed layers and are an indicator of a secondary formation process. Depending on the mineral composition, or silica content, of these dikes (or intrusions) they will be either felsic, intermediate, or mafic, with felsic rocks containing the most silica. There are several kinds of secondary igneous rock formations found in the Kunlun called dikes. If the composition of the dike is different from the surrounding rock, this will provide insight into how the dikes formed in the Kunlun and how it can be explained using plate tectonic theory. 

Granite is a commonly found felsic rock in the Kunlun and is formed intrusively (or underground). The mineral contents of the granite can tell the researchers how fast or slow the magma cooled, which will ultimately help answer the question of how the dikes formed. Within the granite, there were zircon crystals present with radioactive uranium decaying into lead. These ratios were recorded in order to estimate ages within the mountain range to determine when the different magma-cooling events took place. To summarize, this paper uses physical samples of the igneous rocks in the area to study mineral composition and isotope data from these rocks, too. 

Methods: The samples that were collected from different rock types in this area were studied under a microscope in order to observe the composition and individual mineral grains. In plate tectonics, there are two kinds of plates: continental plates and oceanic plates. Granite (felsic) comprises less dense continental plates, while basalt (mafic) comprises a denser oceanic plate. In the Kunlun, the researchers observed several granite inclusions surrounded by mafic rock. The isotope ratios of uranium to lead were recorded and radiometrically dated. These data determine if the different intrusions formed at the same time, or if they formed during several events. This would help support or reject the hypothesis they posed that when the continental and oceanic plates collided, creating the Kunlun Mountains, the edge of the oceanic plate broke while bending under the continental plate (the oceanic plate always goes underneath a continental plate, due to higher density).

Results: The radiometric dating of the granite inside the intrusions (the magma formations added after the formation of the surrounding rock) indicated four different formation events, with the earliest taking place 427-414 million years ago (mya) and the latest from 373-357mya. (For more about how radiometric dating works visit Geologic Time.) The variation in the composition of the rocks (felsic, mafic, etc) indicates a complicated tectonic history; along with the multiple events of granitic intrusions, scientists also found ophiolites (oceanic crust that was pushed onto land during an oceanic- continental plate collision), which indicates that a piece of the oceanic plate was pushed up and broken off during the collision. 

A volcano sits on top of igneous rock layers. The volcano is not erupting, but has a magma plume underneath it. There are also intrusive igneous rock formations in the figure. There is a pluton (depending on its size, it is either a stock or batholith) and there are dikes cutting through the rock layers. The rock layers are labeled on the left side, in order of fastest cooling, smaller crystals on the top, to slower cooling, larger crystal sizes on the bottom. The pluton lies at the very bottom of this image with yellow magma.
This figure demonstrates the relationship of cooling rates to crystal sizes. Since the granite of the Kunlun has large crystals, it would be represented by a dike that was set deeper into the rock layers because of longer cooling periods. The lower horizontal layers represent the mafic layers of the Kunlun, which also had large crystals. Figure Citation: Beckett, Megan. Flickr, Siyavula Education , 23 Apr. 2014, https://www.flickr.com/photos/121935927@N06/13598553484/. Accessed 30 June 2022.

Why is this study important? This study looked to test the hypothesis of a broken oceanic plate’s impact on the formation of the Kunlun mountain range and gain more specific knowledge of its origin. By taking inventory of its intrusive rock formations, getting radiometric dating for these intrusions, and noting the differences in mineral compositions, they were able to confirm their hypothesized four magma events. These events represent different periods of magma formation, which confirms the researcher’s hypothesis about oceanic plate breakage during a collision. 

The big picture: Clues from igneous geology, such as large crystal size, rock type, and mineral composition can give researchers details on how large formation events took place. Isotopes within radiometric dating were used to separate events from one another and place them in chronological order. This particular study answered questions about the origin of the Kunlun Orogen, or mountainous landscapes.

Citation: Zhang, Jinyang, Huanling Lei, Changqian Ma,  Jianwei Li,  Yuanming Pan. “Silurian-Devonian Granites and Associated Intermediate-Mafic Rocks along the Eastern Kunlun Orogen, Western China: Evidence for a Prolonged Post-Collisional Lithospheric Extension.” Gondwana Research, vol. 89, Oct. 2021, pp. 131–146., https://doi.org/10.1016/j.gr.2020.08.019.

The Scars of a Mastodon’s Tusk and the Story it Reveals About the Mastodon’s Bachelor Experience

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Male Mastodon Landscape Use Changed with Maturation (late Pleistocene, North America)

Joshua H. Miller, Daniel C. Fisher, Brooke E. Crowley, Ross Secord, and Bledar A. Konomi

Summarized by Makayla Palm 

What data were used? The tusks from a single male mastodon specimen (the “Buesching” mastodon, housed in the Indiana State Museum) that died in its early thirties were analyzed in two stages of its life (teenage and adult) in order to understand how, as a bachelor, it moved away from its herd and interacted with other adult mastodons in what was likely a breeding ground. The skull and tusks of this particular specimen have scratches, dents and markings likely caused from fighting with other males over potential female mates. These marks inspired researchers to focus on mating behavior; they hypothesized that the place where the mastodon fossils were found was the same location as its summer breeding ground. Scientists also examined modern-day relatives like elephants, which added insight into the following data: isotope changes in both oxygen and strontium and the growth “rings” of the tusks during teenage and adult years, which shed light on how the mastodon might have moved seasonally. 

Methods: In order to test the hypothesis of the mastodon’s seasonal moving in his later years, scientists examined and compared changes in tusk growth throughout its life. The exterior damage on the tusks was observed and recorded to factor into results. The mastodon tusks grew each year by depositing a ring of dentin, which is dense tissue that is bony, similar to what makes up teeth. By looking at the differences in the rings, scientists can determine changes in lifestyle. In particular, to learn about where the mastodon traveled, two different isotopes were measured: one to determine seasonal temperature changes (an oxygen isotope) and the other for change in environment and age (a strontium isotope).

Results: The visible damage observed on the mastodon’s skull is consistent with a hypothesis scientists proposed of males fighting for territory and mates. This happened in seasonal periods of musth, an annual event where male mastodons experienced extra fighting based on increased aggression while on the search for a mate, leading to increased clashing tusks in the height of mating season. The dentin growth deposits show evidence of low nutrition value in the same growth years the male would be expected to separate from the herd. There was also a noticed abundance of nutrients a couple of years later, inferring it had become successful on its own as an adult. Oxygen and strontium isotopic changes in the tusk show that the mastodon traveled to a warmer location around the same time each year; the two isotope ratios indicate a pattern of more frequent visits to its summer ‘bachelor pad’ (or breeding ground) and as the mastodon got older, it was able to travel further from its typical location. 

Two graphs represent the frequency in which the mastodon visited his breeding grounds. The first graph (on the left) represents his teenage years, and the second graph (on the right) represents his adult years. The adolescent years show no interaction at the fossil location site (where the mastodon bred and was later excavated), but consistent travel far away from the breeding ground. The adult graph shows consistent interaction at the breeding site, indicated with a red horizontal bar above the “near fossil location” label. The adult graph indicates the same consistent travel away from the breeding grounds as the adolescent graph, implying the addition of the breeding ground travel was an addition he found as he sexually matured.
The figure represents the changes in the oxygen isotope that indicate warmer temperatures. The warmer temperatures are inferred to be the mating grounds for this particular mastodon. This figure shows no interaction at this site in its adolescent years, but consistent interaction there as an adult. There is a consistent pattern where it left the breeding grounds in both teenage and adult years. The fossil location is where the mastodon was excavated.

Why is this study important? A male mastodon perished after fighting to the death for a mate. Its tusks were analyzed for growth patterns and changes in trace isotopes to better understand where the mastodon went, its pattern of seasonal travel, and its behavior throughout its lifetime.

The big picture: This story sheds light on the behavior of mastodons as they matured over time, as well as male behavior displayed during mating season. The quality of the preserved tusks allowed researchers to learn about this mastodon’s teenage and adult life and compare the differences over time. 

Citation: Miller, Joshua H.,  Fisher, Daniel C., Crowley, Brooke E., Secord, Ross and Konomi, Bledar A.  “Male Mastodon Landscape Use Changed with Maturation (Late Pleistocene, North America).” Proceedings of the National Academy of Sciences, vol. 119, no. 25, 2022, https://doi.org/10.1073/pnas.2118329119.

Learning About the Leopards in the Cederburg Mountains

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Population size, density, and ranging behaviour in a key leopard population in the Western Cape, South Africa

Lana Müller, Willem Daniel Briers-Louw, Barbara Catharine Seele, Christiaan Stefanus Lochner, Rajan Amin

Summarized by Habiba Rabiu, a student of environmental geosciences at Fort Hays State University. Habiba is interested in all aspects of environmental science and conservation & sustainability. She would like to work in educating others about those topics. In her free time, she likes to read, write, and bake.

What data were used? The researchers chose an area in the Cederburg Mountains in Western Cape, South Africa, about 200 km north of Cape Town. In the Western Cape Province, there is about 50,000 km² of potential leopard habitat, but only 30% of it is in conservation areas or mountain catchment zones. The density of the leopard population in the province is among the lowest in the country with only 0.25–2.3 individuals per 100 km2, however their home ranges are relatively large (35–910 km²). The aim was to determine the number of individual leopards in the region and the amount of land they occupy.

Methods: The area of study chosen was 2,823 km² in size and 73 camera traps were set up with a mean distance of 2.78 km between each trap. The cameras were placed along any trails or natural features that the leopards were likely to come across or had shown evidence of having already been there. The cameras operated 24 hours a day and took three images each time they were motion-triggered. From the pictures taken, the leopards were manually identified and digitally differentiated using a software that could distinguish each leopard’s unique spotted pattern. 

In addition to the pictures, the researchers also used various software and databases to track the population size and density, site use, and ranging habits of the leopard population, as well as any livestock depredation (or attacks) that occurred. This information contributed to creating a more complete picture of the leopards in the area and their movements. One topic that required special attention was the difference between the leopard movements in winter versus the summer, as the changing seasons had a significant effect on how far the leopards had to move for food and other resources.

Results: From the photographs taken, 63 adult leopards were identified (31 females, 26 males, and 6 of unknown sex.) In the summer, the leopard density was estimated to be 1.62 leopards per 100 km² and more concentrated towards the center of the study area, while in the winter the leopards were more spread out, causing the density to decrease to 1.53 leopards per 100 km². In both seasons, leopard density was higher in females with a female to male ratio of 2.42:1 in the summer and 2.45:1 in the winter.

The leopards were found to be present in nearly the entire area studied, with a total of 2,638 pictures being taken of them at 95% of the camera traps. The habitat type and altitude of the different parts of the study area did not seem to make a difference in the leopards’ movement. As could be inferred from the density measurements, the female leopards tended to keep their activity within a smaller radius around the center of the study area, occupying an average space of 117 km² in the summer and 182 km² in the winter, while the male leopards had an average range of 456 km² in the summer and 856 km² in the winter. The average number of instances of livestock attacks did not appear to differ in number from previous research. The mean number of livestock killed was 7.7 during the summer and 14.9 during the winter.

Images are the same size and shape depicting an oval-shaped region. In the left image, the black dots, yellow circles, and red crosses are all situated towards the center of the oval, with little to no activity shown in the outermost ⅓ part all around. Both the black dots and yellow circles appear mostly in clusters, with a few outliers. In the right image, the black dots are shown mostly on the periphery of the oval, with a few clusters in the center. The yellow dots are slightly more spread out but are all situated towards the center of the oval, as are the red crosses.
The image on the left depicts movement of the adult female leopards in the winter, and the image on the right shows movement of adult male leopards. Activity centers are shown as black dots, capture locations as yellow circles, and trap locations as red crosses.

Why is this study important? This research is a thorough study of the leopard population in the Cederburg Mountain region that employed several methodologies and programs. It supports previous research regarding the average low density (less than 2 leopards per 100 km2) of the leopard population in the Eastern and Western Cape Provinces of South Africa. 

The big picture: Since 2016, leopards have been listed as Vulnerable on the International Union for Conservation of Nature’s Red List. This status is due to a variety of factors, many of which are anthropogenic, or human caused, including habitat loss, loss of food sources, poaching for sale or body parts, and killing by farmers attempting to protect their livestock. Tackling issues of conserving threatened animals requires precise data about the animals’ population and activity.

Citation: Müller L, Briers-Louw WD, Seele BC, Stefanus Lochner C, Amin R (2022) Population size, density, and ranging behaviour in a key leopard population in the Western Cape, South Africa. PLOS ONE 17(5): e0254507. https://doi.org/10.1371/journal.pone.0254507

New Species of Sea Anemone Found with Symbiotic Relationship to a Hermit Crab

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Carcinoecium-Forming Sea Anemone Stylobates calcifer sp. nov. (Cnidaria, Actiniaria, Actiniidae) from the Japanese Deep-Sea Floor: A Taxonomical Description with Its Ecological Observations

Akihiro Yoshikawa, Takato Izumi, Taekya Moritaki, Taeko Kimura, Kensuke Yanagi 

Summarized by Michael Hallinan 

What data were used? 16 specimens of a new species of sea anemone (Stylobatus calcifer) were collected by beam trawl from Japan’s Sea of Kumano. All specimens were collected at a depth of 100 to 400m, with 6 of them being treated with ethanol immediately for DNA extraction. Most of the others were anesthetized and treated with a variety of chemicals for structural analysis, only one was further studied through behavioral observation prior to being treated with ethanol. In addition to the sea anemones, the shells used by the sea anemones and the symbiotic host hermit crabs were identified. 

Methods: S. calcifer is a symbiotic species, it lives on the mollusc shells used by hermit crabs of the species Pagurodofleinia doederleini. The collected specimens were removed from the shells they were sitting on and dissected allowing for further analysis using different mixes of chemicals to help preserve and support the dissected parts during this series of observations. Following the visual observation, DNA was extracted from four of the specimens and compared to other species, with further comparisons to the most closely related species to analyze if the specimens found can be attributed to a new species. In addition to this qualitative data, a series of observations between one of the specimens and hermit crab were made in a seawater aquarium. These observations focused on recording the anemone’s interactions with the hermit crab, centered around the hermit crab’s shell, as well as what happened when a new shell was introduced. These observations were recorded and provided as supplementary material.

Results: S. calcifer was identified to be unique in its DNA, the shape of one of the muscles that manages openings in the anemone, direction of its mouth system, as well as the size distribution of its prey-capturing parts. However what sets it apart from previously known species even more is its symbiotic relationship and interactions with the hermit crab P. doederlein. Once the hermit crab discovered and moved into a new shell, it began to detach the sea anemone and encourage the sea anemone to transfer to the new shell through a series of pinches. There was no initial reaction from the sea anemone, but after about 43 hours from the hermit crab getting its new shell, the sea anemone has completed the transfer with it, mounting and covering the new shell. This allows the anemone to move across the seafloor by their hermit crab and collect food, while avoiding injury by being mounted on top of the shell. While symbiotic relationships between hermit crabs and sea anemones are known for over 30 other species, a hermit crab induced transfer to a new mollusc shell has never been observed until now.

A series of graphics labeled A through F that depict the various stages of the transition for the old hermit crab shell to the new hermit crab shell. (A) The hermit crab which has left its old shell and already moved into the new one begins to tap the central body of the sea anemone. (B) It uses its front claws to pinch the top of the anemone and remove the sea anemone from the old shell. (C) There is a lack of shell-mounting action from the anemone after removal. (D) The sea anemone is then flipped upside down by the crab and its center is aligned with the shell. (E) Finally it settles in on the host hermit crab’s new shell.
Behavioral sequence of the hermit crab transferring the sea anemone from the original shell to the new one. (A) The hermit crab which has left its old shell and already moved into the new one begins to tap the sea anemone. (B) It uses its front claws to pinch and remove the sea anemone from the old shell. (C) There is a lack of shell-mounting action from the anemone after removal. (D) The sea anemone is then flipped upside down by the crab and aligned with the shell . (E) Finally it settles in on the host hermit crab’s new shell.

Why is this study important? This study has expanded our understanding of taxonomy regarding sea anemones, but also provided a great observation of symbiosis between the hermit crab and anemone which not only allows us to better understand how both function but also opens the door for future research about the association between the two. All of this knowledge can better improve our ability to conserve as well as better understand relative biodiversity.

The big picture: A new species of sea anemone was discovered to have unique structural properties regarding its mouth and prey-capturing parts as well as a very unique symbiotic relationship with a hermit crab. The anemone is encouraged to transfer from shell to shell by the hermit crab. It mounts the shell inhabited by the crab as a means of transportation so it can acquire food easier. This new discovery allows us to better understand both respective organisms and their patterns but also conservation regarding both.

Citation: Yanagi, Kensuke (2022/04/01). Carcinoecium-Forming Sea Anemone Stylobates calcifer sp. nov. (Cnidaria, Actiniaria, Actiniidae) from the Japanese Deep-Sea Floor: A Taxonomical Description with Its Ecological Observations. The Biological Bulletin, 242, 127-152. doi: 10.1086/719160