Climate & Paleo News

Here we will dissect recent publications in the fields of climate and evolution. Our goal is to provide a logical narrative while also picking out the data and importance of each study.

The discovery of a new macro-spined spider-like arachnid species reveals more on the late Carboniferous Period

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A remarkable spiny arachnid from the Pennsylvanian Mazon Creek Lagerstätte, Illinois

By: Paul A. Selden and Jason A. Dunlop

Summarized by Alivia Tom. Alivia is an undergraduate student at Binghamton University who is working towards a Bachelor’s of Science in the Biology Department. She loves to go on hikes and explore nature in her free time.

What was the hypothesis being tested? In this paper, paleontologists Paul A. Selden and Jason A. Dunlop report the results of studying a newly described that was originally discovered in the 1980s. Researchers examined a spider-like fossil from the late Carboniferous Period (~323–298 mya) to determine whether this specimen represent its own new species based on its identifiable characteristics, or if it belongs to an already existing species.

What data were used? Researchers examine a single specimen from the Pit 15 Northern Mine spoil heap located in the Pennsylvanian Mazon Creek in Illinois, USA. This area is classified as a Lagerstätte, which is a geologic unit that has the ability to preserve fossils extremely well. Many other well-preserved fossils have been discovered from this area, including other arachnids and mites. This specimen was compared to many other identified fossil organisms, mainly other arachnids. The data for the other species was sourced from data sets in research papers created by many other scientists. Some of the body parts that were compared included its abdomen and legs, as well as the shape of its body. 

Methodology: The person who had found the fossil in the 1980s, Bob Masek, decided to leave the fossil in water during the winter. This allowed the water to run through the existing cracks of the material surrounding the fossil, and then expand through freezing. A hammer was then used on the surrounding material to reveal the fossil. After the discovery and reveal of this fossil, it was passed to the Douglass family Prehistoric Life Museum in Illinois, USA,  and then donated to The Field Museum of Natural History for further research. A Canon EOS 5DSR digital camera alongside a Leica MZ16 microscope and low-angled light were used to take pictures of this fossil. When these two instruments were used together, the intricate forms and structures of the fossil were revealed. Pictures of different angles of the fossil were taken to capture details that other angles could not see, and these pictures were layered on top of each other. Through the combination of multiple photographs and further detailing using a microscope, drawings of the fossil were created using Affinity Designer 2 (Fig 1.). Researchers contrasted the differences from the body layout of the new specimen to other studied species, such as how each body part was attached to each other, how they fused to each other, and how the lengths of each body part compared.

Results: This fossil was classified as an arachnid, because of its four pairs of legs, two body parts, fused head and chest, and segmented rear end. However, it was not placed into any existing species due to its distinct large spines on its legs, a very fused head and chest, and very large and equivalent legs. Scientists classified this specimen as a new genus and species, after comparing many of its characteristics to other existing or extinct species that appeared to be similar. This conclusion was reached after determining that the characteristics of the fossil did not match any known arachnid species. Some of its differences include its large spiky spines. They named the new genus and species Douglassarachne acanthopoda. Its differences also do not allow it to be placed into any existing order. An example of a difference that it had was that all its legs appeared to have the same frame and length, setting it apart from harvestmen. Harvestmen are an order of arachnids that have an oval shaped body and thin legs that are of varying lengths.

There is a figure with an oval-like body and four pairs of two limbs attached to the body. The first pair of limbs is shorter than the rest of the limbs, and large spines are attached to each limb. This figure is encrusted in a rock surface. The figure on the right is a drawn image of the photograph on the left. Specimen is about 20 mm wide by about 35–40 mm in length, including legs.
Figure 1. An image of the new spiny arachnid, taken with a Canon EOS 5DSR digital camera (left) and a line drawing of the specimen (right). The material surrounding the arachnid was emphasized using different angles of low light. The spines are emphasized in this picture, which may hint towards defense mechanisms of the late Carboniferous. Scale= 5 mm.

Why is this study important? This study could make scientists consider a wider range of possible body plans that may have existed in the late Carboniferous, as this arachnid’s body plans did not match any that were previously discovered. Scientists also created hypotheses of what the purpose of these spiny spikes were used for. They hypothesized that they could have been used for defense, creating a longer handling time for predators, increasing their ability to escape and survive.

Broader implications beyond this study: Further studies on this area could also reveal more about the fossil record of the Carboniferous period, as Mazon Creek is known to be able to preserve soft tissue. Even fossils with hard tissues are difficult to preserve, and fossils with soft tissue are even more difficult to preserve as their bodies typically decay quickly after death.. 

Citation: Selden, P. A., & Dunlop, J. A. (2024). A remarkable spiny arachnid from the Pennsylvanian Mazon Creek Lagerstätte, Illinois. Journal of Paleontology, 1–7. doi:10.1017/jpa.2024.13

Studying the teeth of past and present lemmings to reclassify their ancestors in Western & Central Europe

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Re-investigation of fossil Lemmini specimens from the early and Middle Pleistocene of Western and Central Europe: Evolutionary and paleoenvironmental implications

By Louis, A., Tereza, H., Aurélien, R., Sophie, M., Oldřich, F., & Ivan, H. 

Summarized by Luka Del Canto. Luka is a senior at Binghamton University studying biological sciences. He plans to finish his bachelor’s degree and pursue a master’s in genetics, with the ultimate goal of becoming a genetic counselor. Luka is also an avid sports fan who spends most of his Sundays watching football with his friends. Additionally, he loves to go on hikes when the weather is nicer and has a passion for cooking as well.

What was the hypothesis being tested? Researchers from this study hypothesized that a genus of the lemming species known as Myopus was wrongly disregarded during the European Pleistocene fossil record (2.6 Ma-11.7Ka), and that it actually coexisted with other lemming genera like Lemmus during this period. These small arctic rodents have very similar dental morphologies, which is what made them so hard to distinguish from one another, and the reason they were previously regarded as just Lemmus. This study will also test the validity of the earliest species of the Lemmini tribe, L. kowalskii, and whether or not it can be considered the ancestral form of the Lemmus genera.

What data were used? The study included lemming specimens from fossil and living species, including well-preserved skulls, mandibles, and isolated teeth obtained from museums and fossil siles. A total of 65 M1 and 41 M3 fossil teeth were gathered from eight locations in the Czech Republic, France, and Germany, representing early to middle Pleistocene populations. Another 295 third upper molars (M3) and 324 first lower molars (M1) were collected from museums as living species referential data. To analyze taxonomic differences between the genera Lemmus and Myopus, detailed measurements of dental features were taken with focus on tooth size and shape. Then, these measurements were used to perform statistical analyses to identify morphological variations and potential evolutionary relationships.

Methodology: Researchers outlined specific points on the teeth called landmarks and mapped them out digitally. Since the teeth of fossil and living specimens differed in size and orientation, those differences needed to be removed to prepare them for further analysis. A Generalized Procrustes Analysis (GPA) aligned the teeth landmarks, and principal component analysis (PCA) was then used to analyze all the dental features by summarizing the data into a few principal components. Researchers then identified variations and similarities between these features in fossil and living specimens. Finally, linear discriminant analysis (LDA) was used to take the variations and separate them into different genera like Lemmus or Myopus by finding the features that best distinguished each group. Modern teeth were used as a model to train the LDA into identifying major differences in the genera. Once the model was trained and validated, it was applied to fossil specimens and predicted whether each fossil belonged to Lemmus or Myopus based on its distinguishing features.

Results: Initial results were promising, as many Myopus and Lemmus fossils were both identified at multiple sites, providing proof that they lived in the same time period as they were in the same rock layer. Analysis showed significant shape variation in both M1 and M3 molars, with the first three principal components accounting for nearly 50% of total shape variation (Fig.1). More compact teeth and a less pronounced rear portion of the molar were among the morphological changes observed on the PC graphs. In terms of overall tooth size, fossil populations had teeth similar to Myopus, slightly larger but much smaller than Lemmus, which had the largest teeth for both M1 and M3. Lemmus also had a larger convex hull volume than Myopus, meaning a greater variety in shape and size. However, fossil populations had variation scores comparable to or exceeding those of modern genera, even with fewer specimens, suggesting that the fossils may include multiple genera. The LDAs also showed clear differences between Lemmus and Myopus and were able to assign different fossils to each genus, showing that these genera indeed coexisted during the European Pleistocene fossil record. PCA analysis showed that fossil teeth assigned to L. Kowalskii clustered with modern Lemmus teeth, ultimately validating its taxonomic status as a species within the Lemmus genus. 

Why is this study important? Misassignment of different genera can lead to a misunderstanding of the evolutionary interactions between them. Due to their similar morphologies, Lemmus and Myopus were misclassified as the same genus. Our knowledge of the taxonomic relationships between Myopus and Lemmus in the Pleistocene fossil record were redefined, representing a reliable method for future fossil identification studies. Through the methods used, the study enabled researchers to quantify shape variations that may be missed by more conventional classification approaches that were used in the past like visual inspection and simpler measurements. Modern techniques like GPA, PCA and LDA are particularly useful for differentiating between species that have similar morphologies.

This figure contains seven panels (A–H) analyzing tooth morphology data from various populations of lemmings and fossil samples using Principal Component Analysis and size comparisons. The figure also includes a color-coded legend indicating different groups: Lemmus (modern lemmings)–blue, Myopus–yellow, Koněprusy C718–green, Sackdilling Cave–purple, Schernfeld–pink, L. kowalskii–red star. Each panel focuses on different aspects of morphological variation across these populations. The scatterplots show that Myopus mostly clusters away from the other groups, meaning its tooth shape is noticeably different. Modern Lemmus tends to cluster tightly, with a bit more variation in panels A and E, suggesting their teeth are more uniform in shape. The lollipop graphs in panels D and H show that Lemmus generally has larger teeth for both M1 and M3 compared to Myopus and fossil samples.
Figure 1: PC projections of every axis that explain more than 10% of the shape variation for each molar, with a lollipop graph showing the changes in morphology along the axis’ positive side. PC1 shows differences in mean size and shape, while PC2 explains variation in size of the triangular-shaped side structures on the teeth, and how far back on the teeth they’re positioned. PC3 focuses on front and back curved areas of the tooth, how prominent the side structures are and how distinct the back edge of the tooth is. In A–C each PC is plotted against another to show differences in the lower first molar (M1) between groups of lemmings, and D shows the average M1 tooth (centroid) size between groups with Lemmus having the largest on average. E–H shows the same things but for the third upper molars (M3). For M1, groups seem to differ along the PC2 axis, with Lemmus being the only group on the negative side while Myopus and most fossil populations being on the positive, meaning Lemmus had prominent side structures, while other groups showed smaller side structures that were positioned more towards the back of the tooth. For the third upper molar, the first PC shows a clear distinction in groups as Lemmus and Schernfeld are on the negative side of the axis, while Myopus is on the positive side with Sackdilling Cave, pertaining with more compact teeth (Schernfeld and Sackdilling are individual specimens not yet assigned to a species). Lemmus kowalskii’s position is indicated by the red star, and shows the greatest variation from other groups in graphs F and G.

Broader implications beyond this study: The results of this study have wider ramifications for our comprehension of species classification and divergence in the fossil record. The history of the Lemmini tribe has changed as we now know that Myopus and Lemmus coexisted. The capacity to distinguish between closely related species by dental morphology aids in the reconstruction of an evolutionary history with greater accuracy, not only for lemmings but possibly for other mammals as well. It also calls into question the validity of earlier taxonomic hypotheses and the necessity of reexamining other ancient groups that have morphological similarities, like voles and muskrats.

Citation: Louis, A., Tereza, H., Aurélien, R., Sophie, M., Oldřich, F., & Ivan, H. (2024). Re-investigation of fossil Lemmini specimens from the early and Middle Pleistocene of Western and Central Europe: Evolutionary and paleoenvironmental implications. Palaeogeography, Palaeoclimatology, Palaeoecology, 641, 112128. https://doi.org/10.1016/j.palaeo.2024.112128

Unique colonies found in fossilized Cambrian green algae

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Colonial green algae in the Cambrian plankton by: Thomas H.P. Harvey

Summarized by Jacob Hood is a senior at Binghamton University studying biology. He plans on attending graduate school for ecology and joining the field of environmental conservation. In his free time Jacob enjoys hiking and spending time with his adorable cat.

What data were used? The data used in this paper are microfossils of green algae fossilized in colonies from millions of years ago. These fossils were found in the Fortean Formation of Newfoundland and Labrador, Canada, dating from the Cambrian, around 506–514 million years ago. Scientists created thin sections (slides for a microscope); from the collected data, 59 colonies were identified and analyzed using transmitted light micrographs–think of a standard microscope with a lens on top and light shining up through a slide. Then images were then created using two wavelengths of light together to create a clear visual contrast to human eyes, known as differential interference.

What was the hypothesis being tested?  This paper is a report on findings of microfossils from the early Cambrian. These well-preserved phytoplankton give us insight into a pivotal moment in planktonic (organisms that float in the water column) development, when colonies began to take on new structures to deal with new predation and ecological changes. This allows us to see when and how ecosystems were drastically changing during the transition between the Proterozoic roughly 2.5 billion years to 541 million years old and Paleozoic from 541–252 million years ago.

Methodology: Targeted sampling locations included fine-grained, unaltered mudstones from the Middle Shale Member of the Fortean Formation, which were observed at three different sites: Mount St. Margaret Quarry, the ‘Ten Mile Lake Quarry’ located in western Newfoundland, and the L’Anse-Au-Loup Quarry in southern Labrador. Samples were collected based on knowledge of ancient geographic zones. Collections were taken at what were once moderate ocean water depths on an exposed shelf area beneath the storm wave impact zone. Occasionally, there were thin layers of organic matter made of many fragments of solidified algal organisms deposited during storms, and the samples were layered near the interpreted peak flooding surface, where the water level was interpreted to have reached its maximum depth in a particular area during this time in the early Cambrian, exactly where these algae would have lived or been dropped during their lives. Many other fossils found in the area are typical of the Cambrian, such as early arthropods (the group that contains lobsters) like trilobites, small cone-shelled creatures called hyolithids, early echinoderms (the group that includes sea stars), and sponges,. Up to 50 g samples were analyzed using conventional microfossil methods consisting of placing microbe fossils in a water solution and placing them on a slide and waiting until they’ve been dried enough for a clear image.This is known as a strew slide. Other samples were prepared through a modified hydrofluoric acid extraction method specifically designed for small carbonaceous fossils (SCFs). Out of the 59 colonies that were found, 46 were located on palynological strew slides, surrounded by thousands of unidentified specimens. 13 specimens were then carefully selected from leftover materials containing SCFs, such as bits of sponge skeleton, sections of early worm bodies, and armor-like plates called sclerites from a slug resembling creature known as Wiwaxia. These 13 specimens were placed one by one on glass slides with a pipette then left to dry and looked at under a microscope These samples were then digitized using images from light microscopes created with differential interference contrast, a type of microscopy where electrons are sent to meet at specific planes of the slide and are merged to create a clear and strong signal to be measured electronically for observation. Images were then illustrated, and traits were measured and categorized based on morphological characteristics such as size, shape, and number of cells per colony.

Results: Throughout the samples, cell size, colonial structures, cell attachment, and number of cells per colony varies significantly when measured. There is no straightforward connection found between the size of a colony, the number of cells, and the size of each individual cell. Generally, colonies with a greater size tend to have larger cells, and algae with struts, which connect cells to each other in a colony, are only present in bigger specimens. On the other hand, ring-shaped colonies that consist of a circular colony of algae were found with cells that are smaller in size. However, similar cell configurations may be seen at various sizes: for example, 12-cell colonies arranged in a hexagonal pattern can exhibit either spacious struts creating a small space between cells or denser cell arrangements with closely packed cells, while star-shaped plates composed of seven or eight cells varied in size from 40 to 95 µm in diameter. Overall, there was a wide range of sizes and considerable diversity in these ancient microbe fossils, which continued to increase during the Cambrian (Figure 1).

This image depicts different colonial shapes; ring-forming colonies that take on a empty circular shape, strut-forming colonies which use thin bridge-like structures to connect, and plate-forming colonies which make flat clumps and usually connect directly between cells. The scale bar is 20 microns and most of the subparts are about 40–120 microns wide.
This figure depicts colonial microfossils found. The different colony forming structures can be seen, such as ring-forming (g,l,p,q,r), strut-forming (a,f), and plate-forming (b-e, h-k, m-o, s-u).

It is challenging to differentiate distinct subgroups of these algae due to the similarities in the shape and placement of hairs and spines which poke out from cell walls and give cells texture, the range of cell and colony sizes, and the overlapping colony patterns and cell connections present. The collection instead appears to indicate an individual species that exhibits a high degree of variability, or a small group of interconnected species sharing a similar basic biology. It is believed these algae grew as entire colonies from the moment they split form the mother colony, a strategy not common before or after the Cambrian. This is a stark difference from the single celled growing algae seen before this period, which likely evolved to deal with an increased number of large predators in the environment by growing in larger cells sizes and larger cell clumps.

Why is this study important? This study provides an insightful look into the appearance and relationships between algae in one of the most profoundly changing environments in the history of life. The Cambrian Period is time of rapid evolutionary change in organisms, and the green algae lineage has existed long before and long after the Cambrian. This time period offers a glimpse into the major changes that took place during this time, giving us a look into the very base of the food chain during a time that was incredibly formative for life as we know it. This organism shows potential response to predators by evolving larger and more complex forms. 

Broader implications beyond this study:  The specimens found in this study imply unique physical characteristics and colonial structure in green algae during the Cambrian Period. With these organisms serving as the base of many early food webs, understanding their evolution and the pressures they were under to form these shapes, as well as the relationships they formed with other early organisms, provides a crucial line of questions as to how life first evolved into complex forms.

Citation: Harvey, T. H. (2023). Colonial green algae in the Cambrian Plankton. Proceedings of the Royal Society B: Biological Sciences, 290. https://doi.org/10.1098/rspb.2023.1882 

Exploring the hydrodynamic secrets of frond-like fossil Fractofusus misrai: its survivability in different positions and the impacts of water currents

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Hydrodynamic Insights into the Paleobiology of the Ediacaran Rangeomorph Fractofusus misrai

By: Daniel Pérez-Pinedo, Robert Nicholls, Jenna M. Neville, Duncan McIlroy

Summarized by: Hilla Delouya is currently a senior at Binghamton University, majoring in biology with a minor in evolution. Hilla is fascinated by the mysteries of ancient life and how these early organisms interacted with their environment. When not buried in textbooks, Hilla loves exploring nature through hikes and drinking lots of coffee. 

What data were used? This study dives into the ancient world using computer simulations based on detailed 3D models of Fractofusus misrai, an organism that called the deep sea its home over 560 million years ago, also known as the Ediacaran Period. By simulating how water flowed around this leaf-like rangeomorph (i.e. a branching-style fossil from the Ediacaran) organism, researchers could peek into how Fractofusus misrai might have interacted with its environment to thrive.

What was the hypothesis being tested? The core question of this research was to figure out how the orientation of Fractofusus misrai, relative to the ocean currents, could have influenced its ability to get nutrients and breathe. Essentially, the team wanted to know if there was a strategic way that Fractofusus misrai positioned itself to make the most out of its surroundings.

Methodology: The method of choice was computational fluid dynamics (CFD), a fancy term for using computers to analyze and visualize the dynamics of fluid flows. This technique was integral for simulating the interactions between water currents and the complex three-dimensional geometry of Fractofusus misrai. By creating detailed 3D models based on the latest paleobiological data, researchers were able to simulate various water flow scenarios around this ancient organism. The simulations adjusted for variables such as flow velocity and direction. This allowed the team to predict optimal positions for the ways Fractofusus misrai adapted for nutrient uptake and respiratory efficiency within the changing currents of its environment.

This figure depicts a detailed 3-D computer-generated visualization of Fractofusus misrai, portrayed as a leaf-like structure, as it interacts with surrounding ocean currents. The simulation displays the organism in three distinct orientations: vertically, horizontally, and tilted at a slightly acute angle on the theoretical ocean floor. Each orientation is exposed to three different speeds of water currents. The speeds are depicted using varying color gradients and arrows. The colors shift from blue to red to indicate the transition from slower to faster water speeds, depicting the amount of drag the organism experiences in the position along with the current speed, which represents the flow of water as it moves around and interacts with the organism's unique structure is influenced by its position relative to the current.
This figure illustrates the interaction between Fractofusus misrai and the ocean water currents of its predicted environment through the use of a computational fluid dynamics (CFD) simulation. The simulation shows the flow of water around its structure in three different positions with three different water current speeds. The three positions consist of vertical, horizontal, and a slightly acute angle. The color gradients and arrow indicate the speed and direction of the water flow that goes through the leaf-like organism. These patterns depict how the organism’s shape influences water movement, aiding in nutrient absorption and respiratory efficiency, which is crucial for the organism’s unique morphology and how it survives in its deep-sea environment.

Results: What researchers found was quite remarkable. By positioning Fractofusus misrai at a slight angle, compared to directly vertical or horizontal to the ocean current, not only minimized drag on the body, but also maximized its ability to collect food and breathe. This strategic positioning likely played a key role in the organism’s survival and efficiency in its deep-sea environment. Thus this slightly angled position allows Fractofusus misrai to better interact with the water around it, reduce drag and not only survive but thrive in its environment.

Why is this study important? Understanding Fractofusus misrai isn’t just about looking back into Earth’s past. Rather, it’s about seeing the bigger picture of life’s early playbook. This study sheds light on the sophisticated ways that Fractofusus misrai and similar organisms might have adapted to their environments, highlighting the complexity and adaptability of early life.

Broader Implications beyond this study: These insights are like opening a time capsule on ecological dynamics of the Ediacaran seas, shedding light on evolutionary innovations during a period when life on Earth was just starting to get complex. It’s a look back at how the foundations of marine ecosystems were laid, offering a lens into how adaptation and survival started, and is still relevant today.

Citation: Pérez-Pinedo, D., Nicholls, R., Neville, J. M., & McIlroy, D. (2024). Hydrodynamic insights into the paleobiology of the Ediacaran rangeomorph Fractofusus misrai . Science, 27(6), 110107. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11214322    

Newly discovered fossil frogs shed light on the Amazonian environment 10 million years ago

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Fossil Frogs from The Upper Miocene of Southwestern Brazilian Amazonia (Solimões Formation, Acre Basin)

Fellipe P. Muniz, Marcos César Bissaro-Júnior, Edson Guilherme, Jonas P. De Souza-Filho, Francisco R. Negri, and Annie S. Hsiou

Summarized by Ryan Taylor. Ryan lives in Clearwater, Florida, and is a student at the University of South Florida (USF) who is currently seeking a B.Sc. in geology. He also works as an assistant engineer for a civil engineering company in Tampa, Florida. One of Ryan’s favorite activities is going garage sale hunting every Saturday morning.

What was the goal of the paper? This study used newly discovered frog fossils, from the genus Pipa and Rhinella, from the southern Amazon to gain a greater understanding of what the biodiversity and the environment of the southern Amazon was like in the Late Miocene (6 to 11 million years ago). Scientists accomplished this by comparing the differences in the structure of the newly discovered Pipa and Rhinella to modern-day frogs of the same genus (a taxonomic rank above species).

What data were used?  Scientists used the bones of the frogs that were found at the Talismã site in the southern Amazonas of Brazil. These bones included the frogs’ ilium and ischium (hip bones), humeri (front legs), and other parts of the frogs’ skeletal structure. This fossil data was compared with data collected from previous studies for small, fossilized animals found in the same region. The researchers also collected samples of the bones of frogs that live in that area today to compare the differences in the structure against the fossil frogs that were found.

Methods:  The researchers recovered multiple samples of frog bones that were in the southern Amazonas region of Brazil by examining an exposed section of sediment layers (Fig. 1). Next, they identified differences in the bone structures of the fossil frogs as compared with the same species of living frogs that are found in the same area today. Using this data of the differences in bone structures, researchers performed an evolutionary tree analysis of the frogs they found to how they were related to other frogs alive today. This tree allows the researchers to see how the frog diversity changed over time to what we have today. They compared the bone structures of the newly found fossils to frogs known to be living there in the late Miocene supporting that the new frog fossils used to live there at that time too.

This figure shows a map of Brazil and focuses on a part of Brazil in the southwestern Amazon with the location of the fossil excavation and some of the rivers that are in the area. There is also a representation of a 5.3-meter-tall cross-section that was in the ground. This cross-section showed the clay/mud layers and the different types of fossils found in them. Reptiles were found between 1.12 and 0.68 meters deep. Fish, anurans (frogs), mammals, reptiles, and crustaceans (crabs) were found between 2.15 and 2.34 meters deep. More crustaceans were found between 2.34 and 4.89 meters deep.
Figure 1 shows the area where the samples of the new frog species were found. The layer in which the bones were found is helpful in finding the approximate age of the frog bones because each layer down from the top represents an older time in geologic history. The anurans (frogs) were found between 2.15 and 2.34 meters deep. Other animals that were found include: crustaceans, fish, mammals, and reptiles which all lived in the same time period the frogs lived.

Results: The researchers found two frog taxa here belonging to the genera Pipa and Rhinella. The results of this study showed that a diversity of frogs in genus Pipa lived in the southern Amazonas region. The Pipa fossils that were found are some of the oldest for the genus which supports a previous study that was done in Venezuela, showing Pipa also lived there in the late Miocene. The discovery of Pipa in the southern Amazonas gives an idea as to what type of environment this region had. Pipa is only known to live in aquatic environments near stagnate waters like lakes and swamps, showing that this is likely the type of environment that existed here in the late Miocene. Frogs in the genus Rhinella are not very dependent on aquatic environments and can live in a broader variety of habitats, but their tadpoles are dependent on a nearby water body. This study also found a possible new species of frog belonging to the genus Rhinella that also lived in the area. There are differences in the pelvis of the fossil Rhinella compared to today’s frogs, indicating that they are different species.

Why is this study important? This study is important because it showed what type of environment the southern Amazonas had in the late Miocene. They were able to see that the Amazonia used to have more lakes and was possibly less tropical, as compared to its modern-day rainforest environment. This study also added clarity to the evolutionary history of when these types of frogs may have evolved.

Broader Implications beyond this study: Any land species, like frogs, are not commonly preserved in the fossil record.  When these rarer fossils are found, they offer massive contributions to the scientific community.  

Citation: Muniz, F. P., Bissaro-Júnior, M. C., Guilherme, E., Souza-Filho, J. P., Negri, F. R., & Hsiou, A. S. (2022). Fossil Frogs from the Upper Miocene of southwestern Brazilian Amazonia (Solimões Formation, acre basin). Journal of Vertebrate Paleontology, 41(6). https://doi.org/10.1080/02724634.2021.2089853

Finding traces of food and guts in 588 million years old Ediacaran-type critters

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Guts, gut contents, and feeding strategies of Ediacaran animals.

Summarized by Nilmani Perera, a graduate student in the PhD program at the Geological Sciences program at the University of South Florida. She’s studying evolutionary patterns of Paleozoic (542–251 million years ago) echinoderms with Dr. Sarah Sheffield. She’s also interested in looking into their paleoecology and how it could have played a role in their diversification during this time. 

What was the hypothesis being tested (if no hypothesis, what was the question or point of the paper)?  This study focuses on understanding how Ediacaran animals fed, using three 558-million-year-old fossils from the White Sea area in Russia.

What data were used? Three different fossilized animals were used in this study; Kimberella, Calyptrina and Dickinsonia; Figure1). Rocks containing fossils and surrounding sediment from White Sea area in Russia were analyzed for the presence of fat molecules (lipid biomarkers) that came from their diet.

Methods: Fossils  and sediment collected in the field were prepared and then analyzed using Gas chromatography–mass spectrometry (GC-MS). This is a method used to separate components in a mixture at very fine level, basically at the molecular level. Fat particles in the samples were separated based on their differences in chemistry. Researchers looked for the presence of specific combination of lipid molecules in these samples, which can indicate the origin of the molecules. Comparing the ratios of the different types of molecules allowed them to figure out whether the signal came from the actual organisms or from the surrounding rock. This also allowed researchers to determine if the organism had a digestive tract (also referred to as gut) inside its body

Results: There were several significant findings that came out of this study. First, researchers discovered that the lipid breakdown process in Kimberella and Calyptrina is the same as in modern invertebrates, such as mollusks (like clams) and worms. Secondly, they were able to point out that Kimberella grazed on microbial mats and Calyptrina fed on particles in the sea water or in the marine sediment, like modern day tube worms would do. Thirdly, it was shown that both these organisms had a gut in which their food was digested. Interestingly, none of the specimens of Dickinsonia studied indicated that they possessed a gut, so they either took in food particles by osmosis (where particles move across a membrane) or could have possessed an external digestive system in which they secreted enzymes into the environment to breakdown food and then absorb it through their body. 

The figure contains three Ediacaran animals preserved in rock as fossilized impressions. A. The first figure is of Kimberella, preserved in a light gray color rock and is roughly half an inch long. It is pear-shaped, flat and has a couple of layers to it. B. The second figure is of Dickinsonia, preserved in a light brown color rock. It is leaf-like with ridges radiating from a central axis and about 3.5 inches along its length. C. The third figure is of Calyptrina, preserved on the surface of a beige color rock. It is flat, long, and worm-like with some dark color patches along its length.
Figure 1; Ediacaran fossils used in this study. A. Kimberella, B. Dickinsonia, C, Calyptrina (Scale bar used in Figures A, 5mm; B, 10mm and C, 5mm)

Why is this study important? The findings of this study are important because there’s a lot of research going on to understand how earliest animals evolved and how similar they were to animals we see today. Ediacaran- age animals represent an important turning point in the study of how animal bodies came about and how similar they are to major animal groups we see today. In this study, the lipid molecules preserved with the fossils  allowed researchers to compare them to modern animals with similar life modes. 

Broader Implications beyond this study: This method of biomarker identification can be applied to learn more about the trophic structure in ecosystems that are hundreds of millions of years old. The beauty of it is that this method can be used even when the gut is not preserved, because the method is only using the lipid molecules derived from the diet. 

Citation: Bobrovskiy, I., Nagovitsyn, A., Hope, J.M., Luzhnaya, E., & Brocks,J.J.,  (2022). Guts, gut contents, and feeding strategies of Ediacaran animals. Current Biology, 32, 5382–5389. https://doi.org/10.1016/j.cub.2022.10.051

Using Shark Teeth to Compare Past and Present Shark Populations Along the Southern Coast of Brazil

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Quaternary fossil shark (Neoselachii: Galeomorphii and Squalomorphii) diversity from southern Brazil

Sheron Medeiros, Maria Cristina Oddone, Heitor Francischini, Débora Diniz, Paula Dentzien-Dias

Summarized by Max Raynor, a 4th year undergraduate student pursuing a bachelor’s degree in geology from the University of South Florida. Max currently works for a surveying company in Tampa, where he focuses on making digital maps of the Earth’s surface and ocean floor.  When he isn’t studying geology or working, he enjoys fishing, collecting and curating vintage clothing, and playing tennis.

What was the hypothesis being tested? Scientists used fossil shark teeth to quantify differences between shark populations throughout the Quaternary Period (the past 2.58 million years of Earth’s history). The shark teeth used for this study were collected along the beaches of the Rio Grande do Sul Coastal Plain (RSCP), which extends along Brazil’s southernmost shorelines. Scientists compared and contrasted structural differences between shark teeth to test hypotheses on changing climate conditions throughout the Quaternary and how changes over time affected shark populations along the Rio Grande do Sul. 

What data were used? The data collected in this study included 3,611 shark teeth that had been found on the beaches of the RSCP since 1996. Using the simple technique of manually collecting shark teeth from the beach, researchers were able to find a variety of species to use for this study.

Methods: Participating in a well-documented data collection process known as “beachcombing”, researchers scanned the exposed beach area and picked out shark teeth by hand. The gravelly nature of beach grains, as well as the less-than-perfect condition of many of the teeth found, made it increasingly difficult to find desirable samples over time. The collected teeth were subsequently sent to a laboratory where they were sorted and classified by species. A classified tooth would be analyzed from two different views: where a tooth was adjacent to the tongue (lingual), and where a tooth was adjacent to the inside of the mouth (labial). The characteristics of a tooth from these angles provide the information necessary to correctly identify the corresponding shark species.

Results: By observing the characteristics of the teeth sampled, scientists identified 3,611 teeth belonging to13 different species of shark in the dataset (Fig. 1). While about ¾ of the data were able to be identified to the species, some were only able to be identified to the genus, and some teeth were rendered unidentifiable due to physical alterations and erosion over time. The order Lamniformes represented just 3 of the 13 taxa identified, but was responsible for 2,390 teeth sampled, or 66.18% of the dataset. Carcharius taurus, commonly known as the sand tiger shark and belonging to Lamniformes, was the most abundant species overall with 2,027 identified teeth. With respect to species diversity, the majority of the diversity belonged to the shark order Carcharhiniformes, which represented 8 of the 13 species identified. Carcharhinus leucas, also known as the bull shark, was the most abundant species of the Carcharhiniformes with 191 teeth sampled. 11of the 13 species identified are still found in the region, indicating that the shark community and climate conditions of the RSCP throughout the Quaternary have been fairly similar over the past 2.58 million years.

Figure A: Pie chart of shark orders sampled, from highest to lowest percentage of teeth found per order: Lamniformes (2,390 teeth), Carcharhiniformes (821 teeth), Hexanchiformes (10 teeth), Squatiniformes (2 teeth), and 388 teeth that were unable to be identified to the species.Figure B: Pie chart of the number of teeth sampled from each species, from most teeth found per species to least: Carcharius taurus (2,027 teeth), Carcharadon carcharias (283 teeth), Carcharhinus leucas (193 teeth), Carcharhinus brachyurus (90 teeth), Isurus oxyrinchus (80 teeth), Sphyma (51 teeth), Carcharhinus longimanus (21 teeth), Galeocerdo cuvier (18 teeth), Notorynchus cepedianus (10 teeth), Galeorhinus galeus (3 teeth), Squatina (2 teeth), and Rhizoprionodon (1 tooth). There were 444 Carcharhinus teeth that could not be identified to a species, as well as 388 unidentified teeth.
Pie charts depicting (A) The orders of shark represented by teeth collected in this study and the number of samples belonging to each (B) The species of shark represented by the amount of teeth identified per species in this study.

Why is this study important: The diversity of shark species along the RSCP is important to note because it supports hypotheses posed in other studies that climate conditions have changed little throughout the Quaternary in this region. The two species found in the study that are not current residents of the RSCP, Carcharodon carcharias (Great White Shark) and Carcharhinus longimanus (Oceanic Whitetip Shark) are noteworthy, because they live in open oceanic environments today and are rarely found in the coastal RSCP, The presence of oceanic sharks such as these indicate higher sea levels along the RSCP at times throughout the Quaternary Period compared to present day. Periods of cooler and warmer weather were drivers of changes in sea level and climate changes throughout the Quaternary, resulting in periodic occurrences of shark species that migrated from both warmer and colder waters.

Broader Implications Findings from this study will allow paleontologists and biologists alike to assess how coastal and oceanic shark populations respond to a changing climate and marine ecosystem. Further research on this using different methods than beachcombing could potentially identify different results, as beachcombing can sometimes favor the collection of larger teeth, as it ismore obvious it is to the eye of the collector. Bulk collecting, collecting sediment and sorting it in the lab, may capture different results, but this will require future research. 

Citation: Medeiros, S., Oddone, M. C., Francischini, H., Diniz, D., & Dentzien-Dias, P. (2023). Quaternary fossil shark (Neoselachii: Galeomorphii and Squalomorphii) diversity from Southern Brazil. Journal of South American Earth Sciences, 122, 104176. https://doi.org/10.1016/j.jsames.2022.104176 

Cambrian and Ordovician Trilobite Injuries

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New records of injured Cambrian and Ordovician trilobites

Summarized by Matthew Gaborik, an undergraduate student studying geology at the University of South Florida. He will be graduating with the class of 2023. After his undergraduate program, he plans to gain some experience and return to school for a Master’s program. When he’s not studying geology, he likes to play mechanic, kayak, and hike.

What was the point of the paper? The point of the paper was to present new findings on select abnormal (injured or malformed) trilobite fossils in order to expand the record of abnormal trilobite fossils and obtain a clearer understanding of trilobite predation.

Data used: Seven abnormal trilobite fossils, originally housed in the Australian Museum, the Utah Field House of Natural History State Park Museum (U.S.), and the Museums of Western Colorado (U.S.), were gathered for this study because they portray damage to the exoskeleton. These abnormal trilobite fossils were: Lyriaspis sigillum, from the Beetle Creek Formation in Australia, Zacanthoides, from the Half Moon Mine, which is part of the Chisholm Formation in Nevada (U.S.), Asaphiscus wheeleri (two specimens) and Elrathia kingii (two specimens), both of which are from the Wheeler Formation in Utah (U.S.), and Ogyogiocarella debuchii from a quarry in Wales. All formations from which these fossils were sourced are aged to around the middle Cambrian (~510 million years ago), except for O. debuchii, which is from the Middle Ordovician (~450 million years ago). 

Method: Fossils were treated with magnesium oxide (which highlights details on the specimen for photography), photographed, and examined for abnormalities. Additionally, a computer program, ImageJ, was used to measure the dimensions of the specimens and their abnormalities.

Results: L. sigillum specimen was found to have a U-shaped ident on the upper left side of the body. The Zacanthoides specimen was found to have a U-shaped indent on the lower left side of the body. The first A. wheeleri specimen was found to have an L-shaped indent on the lower left side of the body, and a U-shaped indent on the upper left side of the body. The second A. wheeleri specimen was found to have a small injury in the middle of the right-side of the body. The first E. kingii specimen was found to have a W-shaped indent along most of the left-side of the body. The second E. kingii specimen was found to have a V-shaped indent in the middle of the right-side of the body. The O. debuchii specimen was found to have a W-shaped indent towards the very bottom of the body. None of the specimens possess abnormalities that indicate damage due to genetic malformations or sickness. Therefore, it is likely that the abnormalities on these fossils are from injuries. Previous studies have shown that these types of indentations are usually a result of failed predation. Therefore, these abnormalities in the specimens described above (i.e., the indentations; Fig. 1) are concluded to be evidence of failed predation.

Figure one shows photographs of two E. kingii fossils. The fossils are oval shaped with rounded heads and bottoms with defined ridges (spines) across the thorax. The fossils are about 30mm in width. One of the fossils has a W-shaped indent along most of the left-side of its body. The other fossil has a V-shaped indent in the middle of the right-side of its body.
Figure 1: Pictures 1 & 2 show an E. kingii fossil with a W-shaped indent on spines one through seven on the left-side of the thorax (middle section). Pictures 3 & 3 show an E. kingii fossil with a V-shaped indent on spines seven and eight on the right-side of the thorax.

Why is this study important? This study is important because it provides insight into the environment from which these trilobites come from and how the predators in this environment would have operated. For example, this specimen of L. sigillum is the first known case of an injured trilobite from the Beetle Creek Formation, and only the second case of predation from the Beetle Creek Formation (middle Cambrian). Additionally, the abnormalities (injuries) on the L. sigillum indicate that durophages, which are predatory animals that consume organisms with harder exteriors, like trilobite exoskeletons, were likely present in the environment. Furthermore, the A. wheeleri described in this study is the first documented injury on this genus and species of trilobite, which indicates that A. wheeleri may have experienced higher rates of predation than previously believed.

Broader implications beyond this paper: This study is a prime example of how past environments can become clearer with closer examination of fossils. Fossils are one of our best available methods of piecing together the puzzles of the past. As stated before, the injuries on the L. sigillum indicate that durophages might have been present in the environment, which tells us more about how trilobites functioned as prey in the middle Cambrian. Predation rates in the middle Cambrian are not currently well understood, so this evidence adds more information to what is currently known. 

Citation: Bicknell, R., Smith, P., Howells, T., & Foster, J. (2022). New records of injured Cambrian and Ordovician trilobites. Journal of Paleontology, 96(4), 921–929. doi:10.1017/jpa.2022.14

A Study on the Effect of Barnacle Attachment to Loggerhead Turtle Fossils

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Bone Modification Features Resulting from Barnacles Attachment on the Bones of Loggerhead Sea Turtles (Caratta caretta), Cumberland Island, Georgia, USA: Implications for the Paleoecological, and Taphonomic Analyses of Fossil Sea Turtles

J-P Zonneveld, Z.E.E. Zonneveld, W.S. Bartels, M.K. Gingras, and J.J. Head 

Summarized by Jackson Asbrand, a current undergraduate at the University of South Florida’s School of Geosciences.

Data being used: Recent Loggerhead sea turtle skeletal material washed up off the Atlantic coast from Virginia to Florida, USA were the subjects of this study, along with any barnacles that were attached to the turtle skeletons.

The point of this paper: The purpose of the paper is to investigate the relationship between bone modification on sea turtles, such as pits (circular holes) and divots, and barnacles that attached to the bones before the turtle died (Figure 1).

Methods: Scientists gathered the skeletal material at various beaches along the east coast.  The skeletons were measured, described, and photographed, with osteological (bone) elements such as depressions or pits being noted. Some of the barnacle pits were recreated in clay to better study the specific shape of the trace left behind. Finally, all of the osteological features were plotted on a digital master sketch of the entire turtle skeleton in order to compare common types of pits on different bones and across skeletons. Each barnacle was identified on the master sketch using a gray circle. The circle would become darker depending on how many barnacles were found in that specific spot.  

Results: The barnacles leave pits on turtles by using either mechanical abrasion (physically wearing the shell down) or excreting a substance that allowed the animal to permanently attach itself to an object. After attaching to the shell, the barnacle causes bioclaustration, or a biological reaction by the host organism in response to an injury or infection by a parasitic organism (in this case, the barnacle). This leads to the bone holes and pits being created, contributed both by the secretion and the bioclaustration. However, this secretion must be renewed to continue being attached to the turtle, so most of the barnacles fall off after death, leaving only the bone pits remaining. There were six types of bone pits that scientists identified. Type 1 is a shallow, but smooth hole. Type 2 is deeper than type 1 and have a smooth, but still angled bottom, Type 3 is similar to 2, but with a flat bottom. Type 4 is a deep pit with many smaller pits on the bottom. Type 5 is a tube-shaped hole that runs even deeper into the bone. The last type, 6, is a ring-shaped indent on the surface of the bone. Broad bone pits were common on most of the skeletons, some digging deeper into the bone than others; in head bones, these pits were generally shallower. There is also a large range of how many barnacles were actually on the head, ranging from zero to even 70 individual bone pits on one unfortunate turtle. The results are similar for the top part of the turtles’ shells, which had a variety in both the depth and the number of bone pits, although they were slightly more common on the front half of the shell than the back half. On the bottom part of the shell, there is little to no relationship between the modification of the skeletons and the barnacles, as they leave no evidence of it occurring. Type 1 pits were seen on the head bones and both sides of the shell. Type 3, 4, and 5 were only seen on the shell. Type 6 was far less common than the rest of the types and were also only seen on the shell. Types 1-4 were all preserved between the barnacle and the bone, meaning that the barnacles did not use physical force to cause the bone pits, but rather dissolve them using secretions Type 5s used both physical and chemical force, as they penetrated through the skin straight to the bone. Type 6 rings were also caused solely by chemical reactions.

Six pictures of turtles are shown in the figure. One returning to the ocean from the beach, one in the ocean with dozens of barnacles on the back of its shell, a third with smaller barnacles on the side of the shell, a fourth with fewer ones atop the edge of its shell, and a fifth and sixth image are zoomed in to highlight the third and fourth turtles’ barnacles’ locations.
Several loggerhead turtles with barnacles in various spots on their shells, in which some will remain on the bone after the turtle dies. A particularly dense cluster of barnacles can be seen in image C, which all are permanently attached via secretion. The types of pits, like those identified in this study, aren’t specified here, since the pits are classified after the death of the organisms.

Why is this study important?: We can use this data to identify patterns in how barnacles not only attach to Loggerhead turtles and dig deeper into how their relationship works, but also other species of turtles, or even other marine animals with which barnacles could also share a similar parasitic relationship. 

Broader Implications beyond this study: This study creates a template to look further at bone modification on sea turtles other than loggerheads from the Cenozoic and Mesozoic Eras, or in other words, up to 252 million years ago. This study also provides insight into how a symbiotic relationship between two species could be permanently preserved in the fossil record, as interactions such as these are not as often preserved.  

Citation: Zonneveld, J.-P., Zonneveld, Z. E. E., Bartels, W. S., Gingras, M. K., and Head, J. J. (2022). Bone modification features resulting from barnacle attachment on the bones of loggerhead sea turtles (caretta caretta), Cumberland Island, Georgia, USA: Implications for the paleoecological, and taphonomic analyses of Fossil Sea Turtles. PALAIOS, 37(11), 650–670. https://doi.org/10.2110/palo.2022.021 

The Early Evolution of Penguin Body Size and Flipper Anatomy: Insights from the Discovery of the Largest-known Fossil Penguin

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Largest-known fossil penguin provides insight into the early evolution of sphenisciform body size and flipper anatomy

Daniel T. Ksepka, Daniel J. Field, Tracy A. Heath, Walker Pett, Daniel B. Thomas, Simone Giovanardi, and Alan J.D. Tennyson

Summarized by Faris Al-Shamsi, a geology student at the University of South Florida, currently in his senior year of undergraduate studies. His passion for geology fuels his commitment to sharing scientific knowledge with others. Faris is currently working on a project to simplify a challenging scientific article for general audiences, reflecting his dedication to communicating complex ideas to diverse readerships. After graduation, he plans to pursue a career in geology and continue to promote scientific literacy among the public.

Hypothesis: The study investigates new fossils, including the recently discovered largest-ever penguin, named Kumimanu fordycei, found in New Zealand. Scientists used these fossils to clarify the evolutionary relationships between this new species and other know penguin species in the evolutionary history record in order to gain a better understanding of their evolutionary development. 

Data used: Researchers discovered penguin fossils in rocks from the late Paleocene Epoch (55.5-59.5 million years ago). They found various bones, including the humerus (upper arm bone) and wing bones. Researchers also used data sets of previously described fossil penguin species, created by scientists Bertelli and Giannini, which included 279 morphological characteristics to compare different species of penguins.

Methods: First, they created 3D digital replicas of the recently discovered bones using a handheld laser scanner and processing software, then finalized the 3D replicas using a software called Blender. Second, they conducted phylogenetic analyses by analyzing morphological characters between different samples of penguin bone to understand different species of penguins’ relationships and evolution over time. Two types of analysis were used: parsimony analysis, which seeks to find the simplest explanation of an evolutionary tree with the fewest evolutionary changes, and Bayesian analysis, which uses statistical methods to estimate an evolutionary tree. They used a large set of data created by scientists called Bertelli and Giannini with 279 characteristics to compare different types of penguins, and the scientists added data from the new fossils they discovered. The scientists modified existing characteristics which means they compared the physical traits of the new species with old species to determine how similar or different they are. Researchers used the length and proximal width (closest to the shoulder) of the humerus to estimate body mass of different penguin species using mathematical equations. 

Results: The study looked at the wing bones of ancient penguins and compared them to those of modern underwater diving birds like diving petrels and alcids (like puffins) through evolutionary tree analyses. Using the mathematical equations for determining size, researchers determined the new penguin fossils likely belonged to a giant, extinct penguin. The researchers estimated the body mass of the new species, Kumimanu fordycei, to be 148.0 kg (326 lbs) based on the length of its humerus, which measured 236 mm. Researchers found that some features of the wing bones in the ancient penguins are similar to those in fossil flying birds, which suggests that these early giant penguins may have kept some features that were once necessary for flying but would have been less efficient for swimming. Because modern day penguins are far smaller than these fossils, it indicates that smaller body sizes were likely selected for along the evolutionary pathway of these birds. 

Chart with the geologic timeline at the bottom ranging from Cretaceous (73 million years ago) to Pleistocene Epoch (nearly recent) and two penguin family trees on the left side: one on the top constructed using parsimonious comparison of physical traits representing the penguin Kumimanu fordycei as closely related to many other species, while the tree on the bottom constructed using complex statistical analysis and it represents the penguin Kumimanu fordycei sharing the same node (branch) with Kumimanu biceae species. The chart represents a drawing of three penguins on the right, starting from the left, penguin 3, which represent penguin Kumimanu fordycei is the largest one, second we have Petradyptes stonehousei, which is the second largest, and last the extant penguin Aptenodytes forsteri which is the smallest. They have the actual bones inside them that were found in fossils colored in white, while non-preserved bones are colored in gray. Crownward (advanced and closer to the tips of the evolutionary tree) penguins exist more than other species with a lifetime ranging from Paleocene Epoch (65 million years ago) to recent while other species lifetime range from Paleocene Epoch to Eocene Epoch (65 million years ago – 50 million years ago)
Figure 1 This figure shows the family tree of penguins with x-axis representing time in million years and the epochs. Family trees started from the Paleocene Epoch, which was about 60 million years ago. The figure is made up of two different kinds of trees. The first one is based on parsimony analysis which is the simplest explanation of a tree taking the fewest changes of the evolutionary changes, and the second one is based on Bayesian analysis which uses statistical methods. The figure also includes pictures of three different penguin species: 3. The largest known penguin Kumimanu fordycei 4. The second new species and genus Petradyptes stonehousei 5.the living penguin Aptenodytes forsteri. The white bones shown on the pictures of the ancient penguins are the actual bones that were preserved, while the gray bones used to complete the skeleton of the penguin even though they are not preserved just in order to show the difference in size between penguins 3,4, and 5 in physical traits.

Why is this study important? The discovery of the largest penguin humerus ever found, and the estimation of body mass based on this bone provides valuable insights into the evolution and growth patterns of penguins. Additionally, the study provides evidence that penguins reached their upper limit of body size early in their evolutionary history and experienced a decrease in size over time, which can provide insights into the impact of environmental factors such as climate change and competition for food resources on the evolution of organisms.

Broader Implications beyond this study: Body size in the fossil record can open a number of questions about how an animal lived. Researchers think penguins lost their flying capabilities before these larger penguins described here  evolved. This might provide a potential reason for the increase on body size: without the ability to fly, penguins faced fewer selection pressures to keep a smaller body size. Researchers also think penguins evolved in Zealandia, where the fossils from this study were located. The large body size of these particular penguins may have given them better control over their body temperatures (called thermoregulation) and allowed for them to disperse to other areas of the world by being able to swim greater distances. This gives researchers new hypotheses to test about how penguins reached and established populations in other continents. 

Citation: Ksepka, D., Field, D., Heath, T., Pett, W., Thomas, D., Giovanardi, S., & Tennyson,(2023). Largest-known fossil penguin provides insight into the early evolution of sphenisciform body size and flipper anatomy. Journal of Paleontology, 1–20. doi:10.1017/jpa.2022.88