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

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

How ocean acidification and ocean warming modify the physiology of coral reef fishes and the migrating temperate fishes

Future shock: Ocean acidification and seasonal water temperatures alter the physiology of competing temperate and coral reef fishes

Angus Mitchell, Chloe Hayes, David J. Booth, Ivan Nagelkerken

Summarized by Shruti Verma, an incoming undergrad student, interested in environmental science, biochemistry and computer programming. She wishes to become a researcher. 

Hypothesis: The purpose of this paper was to assess the relationship between changing marine environment and the physiology of coral reef fish and competing temperate fish, which are migrating into coral reef fish habitats.

What data were used? 60 coral reef fishes (A. vaigiensis)  and 180 temperate fishes (A. strigatus) were collected from a coast in Australia

Scientists measured:

  • Fish’s energy (total lipid content)
  • Fish’s feeding (stomach fullness)
  • Fish’s ability to deal with stress (Malondialdehyde concentration (MDA) and total antioxidant capacity(TAC))
  • Overall health (Fulton’s condition index)

Temperature and pH levels were monitored regularly inside tanks where fish were kept.


  1. Setting up the tanks: Scientists used transparent water tanks with small holes and bubbled pure carbon dioxide (CO2) to increase acidity. Water temperature was altered to mimic future summer and winter conditions. The temperature of  23°C, and pH 8.1 were selected as control conditions to reflect the current winter temperatures in the natural breeding range of coral reef fish populations.
  2. Initializing shoaling: Two groups were created – coral reef fish mixed (N= 60) with temperate fish (N= 60) of varying body sizes (mimicking actual reef conditions), temperate-only mixed with temperate fishes of similar body sizes (to decrease competitive advantage) (N= 120) After 40 days of treatment, fishes were euthanized, after being fed completely, to analyze stomach fullness. 
  3. Assessing water chemistry: Water’s total alkalinity was measured using Gran titration on the 24-25th day of the experiment.
  4. Measuring protein content, MDA and TAC: The TAC kits measured the total concentration of antioxidant macromolecules, antioxidant molecules, and enzymes in the fish’s white muscle tissue. TAC and MDA were then calculated using specific formulas.
  5. Fulton’s condition index: Individual fish were weighed and measured for length before and after the experiment, and their body condition was assessed using Fulton’s condition index, which was calculated from weight and length. Treatment effects on body condition were determined by subtracting the final Fulton’s condition index from the initial index.


Two horizontal panels. The top is 'Coral Reef Fish' and the bottom is 'Competing Temperate Fish'. There are three circles, the middle (yellow) is the current summer temperatures. To the right, there is a red circle indicating future summer conditions with a box to the lower left with the predicted shifting conditions. To the left, there is a blue circle indicating future winter conditions with a box in the lower right with the predicted shifting conditions.
This diagram shows how future water temperatures and ocean acidification could affect coral reef and temperate fish physiology. Arrows indicate significant changes in measured functions, with comparisons made between future winter/summer and current summer conditions. ‘*’ indicates higher response in mixed-species paired temperate fish, while ‘#’ denotes a significant increase in a given function under projected future conditions.

Key takeaways:

  • Lipid content in coral reef fish increased in colder winters (below 20°C) and exhibited decreased physiological performance, suggesting that they struggled to survive in future winter conditions.
  • In hotter summers (above 26°C), temperate fish experience more oxidative damage.

Coral reef fishes will benefit from ocean warming as their habitat range will increase, but they may struggle to survive during future winters. Simultaneously, competing temperate fishes will benefit from the presence of smaller coral reef fishes as temperate fishes will have a competitive advantage due to their greater body size. But this might not be the case when coral reef fish size increases in future summer. In future summer, temperate fishes will experience higher cell damage, and coral reef fishes will have the competitive advantage. Therefore the combined effect of decreased winter and increased summer temperatures on the competition between temperate and coral reef fish is not entirely clear yet. 

Why is this study important? Understanding the future consequences of migration altered physiology and altered shoaling interaction are crucial to determining the likelihood of survival of a fish species in the face of global warming.

Broader Implications beyond this study: It has been well documented that ocean acidification and ocean warming result in migration of fishes between different zones. However, more research needs to be conducted on the effects this behavior has on the shoaling interactions and the physiology of the migrating fish species. Even the smallest changes in environmental conditions can have great physiological impacts on certain fish species as outlined in this study.   

Citation: A. Mitchell, C. Hayes, D.J. Booth, et al., 2023. Future shock: Ocean acidification and seasonal water temperatures alter the physiology of competing temperate and coral reef fishes, Science of the Total Environment.

New Species of Chalk Forming Organisms and Further Accumulations Found within the Faafu Atoll, Maldives

New Species of Chalk Forming Organisms and Further Accumulations Found within the Faafu Atoll, Maldives 

Summarized by Nathan Baker, who is a senior and future geologist at the University of South Florida. His interest in the geosciences lie within geophysics and tectonics. He hopes to attend graduate school in structure and plate tectonic studies. Outside the classroom, Nathan enjoys going to the gym, hanging out with friends, and being active outdoors. 

Hypothesis: This research aims to pinpoint the distribution of coccolithophores, a type of algae and microorganism too small to be seen by the naked human eye (and the organism that chalk is composed of), in the Faafu Atoll of the Indian Ocean’s Maldives while introducing a new species, Alisphaera bidentata. The study delves into the variety of coccolithophore species in the ocean, examining the correlation between the number of species and water temperature through measuring a number of different variables, explained below. Moreover, this paper provides insight into the ecological and environmental impacts that these microorganisms have on the climate.

Data Used: The study analyzes the area surrounding the island using various data points, such as location, depth, time, weather, temperature, conductivity, pH, O2 levels, O2 saturation percentage, and the amount of chlorophyll in the water. Scientists also collected and identified samples of coccolithophores to determine species diversity. 

Methods: As part of this study, three water samples were collected from Faafu between November 2nd and November 6th, 2018. The samples were taken from both deep reefs (between 45 m and 3050 m deep) and flat reefs (which separate lagoons and the deep ocean). Each sample was recorded with a GPS device. Water temperature and oxygen concentrations were measured at each location. Surface samples of water containing coccolithophores were collected from a boat using a bucket off the coast of the islands. Along with this, vertical water samples at 0 m, 10 m, 25 m, and 40 m deep were collected using devices that can withstand high-pressure environments in the deeper ocean. Once the samples were collected, water analysis began. The first step in analyzing the samples was filtration. Samples containing two liters of water were sent through filters that separated the organisms from the saltwater. These organisms were then dried and viewed under a microscope to record the number, concentration, and types of coccolithophores.

Results: Scientists found that the density of coccoliths in surface waters was lower than that in waters with depths of 1-2 m, and the density continued to increase towards the bottom depths in both the lagoon and deep ocean environments. When investigating the vertical samples, scientists noted that there was a 1℃ decrease in temperature, observed from the surface to depths of 40m, along with a decrease in oxygen concentration within the lagoon environment. Within the open ocean environment, there was a 0.5℃ decrease in temperature, along with a decrease in oxygen concentration. Chlorophyll readings demonstrated overall low concentrations at all stations but showed a slight increase at larger depths.

Out of the multiple coccoliths species identified (16), only two were abundantly common within both open water and lagoon areas. The most abundant species were Gephyrocapsa oceanica and Oolithotus antillarum (as shown in figure 1). The concentrations of G. oceanica and O. antillarum increased with depths in both the lagoon and deeper ocean. Within these increasing depths, minor species also became more prevalent. An interesting find was that all 16 species of coccoliths existed in all of the sampled environments. Researchers also discovered a new species of coccolith (Alisphaera bidentata), which among the lesser commonly occurring species in these samples; further testing will be needed to understand the organism’s lifestyle.

Left: circular coccolithophore comprised of thin ridged plates with a bridge in the middle of each plate. The plates are layered on each other in a stacked orientation building on top of each other.Right: circular coccolithophore comprised of thin smooth plates with a small pit in the center of each plate. These plates are layered on each other with each plate’s connection oriented in the southern direction. Each organism is approximately 5–10 micrometers in diameter.
Figure 1: Gephyrocapsa oceanica (left) and Oolithotus. Antillarum (right); modified from

Study Importance: This study mapped the overall abundance of coccolithophores of the island of Faafu Atoll in the Maldives. The data showed that, of the 16 species found, the most abundant were Gephyrocapsa oceanica and Oolithotus antillarum. Along with these major species, numerous minor species were also detected within the waters around Faafu. Scientists, through this study, were better able to quantify how coccolith diversity is related to water conditions. 

Broader Implications. This study is important due to the effects coccoliths can have on the environment. Coccolithophores can affect the environment through the use of photosynthesis. By removing CO2 within the oceans and atmosphere, coccolithophores play a role in stabilizing ocean acidity and atmospheric conditions, and broadly  play a role in stabilizing climate and ocean health. Additionally, the pH in the ocean can be influenced by the amount of CO2 removed from the water, which, in turn, can prevent marine disasters such as coral bleaching and red tides. Furthermore, comparing the data of these coccoliths to other regions of the world can help identify the rate of CO2 absorption and possibly identify reasons why certain regions are affected by global warming more than others.

Full citation: Malinverno, E., Leoni, B., & Galli, P. (2022). Coccolithophore assemblages and a new species of Alisphaera from the Faafu Atoll, Maldives, Indian Ocean. Marine Micropaleontology, 172, 102110.

Discovery of new fossil net-wing insect species in the Democratic People’s Republic of Korea

A new fossil lacewing (Ithonidae) from the Lower Cretaceous (Barremian-Aptian) Sinuiju Formation, Democratic People’s Republic of Korea

By: Kwang Sik So and Chol Guk Won 

Summarized by Karla Rodriguez, a senior geology undergraduate major at the University of South Florida. She has always had an interest in hydrology and geophysics. She is currently a water quality scientific technician at the Southwest Florida Water Management District. Once she graduates, she is planning to continue work in the private sector of hydrogeology. Outside of work, she loves playing competitive video games, hoping to join tournaments in the future.

Hypothesis: The purpose of this research was to describe the first fossils of a net-wing insect, belonging to the lacewings group, found in the Democratic People’s Republic of Korea (DPRK) and establish these finds as an entirely new genus and species. This paper describes the morphology of Sinuijuala paekthoensis gen. et sp. nov. (gen. et. sp. nov. means new genus and species), and compares it to known, related lacewings.

Data used: Recovered Sinuijuala paekthoensis specimens were encapsulated in a portion of shale (fine-grained sedimentary rock deposited in aquatic environments) within the Lower Cretaceous Sinuiju Formation, located in Sinuiju City, North P’yŏngan province of DPRK.  The lacewings were continuously buried by sediment, flattening the organisms. However, the burial allowed for unique preservation of wing features, head, and thorax (the middle part of the body). Wing venation provides one-of-a-kind patterns that can distinguish net-winged individuals, like lacewings, from other types of winged insects.

Methods: All recovered specimens were kept in the Paleontology laboratory at Kim II Sung University, which is in Pyongyang, DPRK. Microscope photographs of recovered Sinuijuala paekthoensis were taken with a Zeiss Discovery V20 microscope. Drawings of the images were created using Adobe Photoshop software. The number and positions of veins in the wing of the samples were measured using a microscope.

Results: This study provides the first documentation of lacewing fossils in DPRK. Researchers determined that Sinuijuala paekthoensis shares similarities with Ithonidae, a taxonomic family grouping of lacewings. Features like the lack of regular wing veining in part of the wing, and the branching of cross veins further in the middle anterior of the wing, as seen in Figure 1, are shared with the insect family, Ithonidae. Other fossils that have been found in the Sinuiju Formation are fossils of woody plants, indicating Sinuijuala was likely a woodland insect, similar to modern lacewings. 

The top two photographs are both sides of a recovered Sinuijuala paekthoensis gen. et sp. nov. sample, shown side by side. Black and white wing venation drawings are underneath their respective reference photographs. Vein abbreviations which specify parts of the wing are next to the drawings: R, radius; Rs, radial sector; MA, media anterior; MP, media posterior; CuA, cubitus anterior; R1, first branch of R; C, costa; Sc, subcostal. The photographs and drawings are shown with 2.0 mm scale bars. A US nickel is around 2.0 mm thick. The specimens are cemented in yellowish shale; wing, the thorax, and the head is clearly seen on the surface. The wings have Sc veins that start closest to the body, and branch out into Rs, MA, MP, and CuA veins away from the body.
Figure 1. Two photographs of a specimen of Sinuijuala paekthoensis gen. et sp. nov. (A, B) and corresponding line drawings (C, D) which illustrate observed wing venation in the sample image. Vein abbreviations are used to distinguish parts of the wing: R, radius; Rs, radial sector; MA, media anterior; MP, media posterior; CuA, cubitus anterior; R1, first branch of R; C, costa; Sc, subcostal. The wings have subcostal veins that start closest to the body as singular veins, and branch out into multiple veins veins away from the body. There were many subcostal veins observed, but fewer costal cross veins were present, which the authors noted as important in describing this particular fossil.

Why is this study important? The recovered specimens introduce a new genus and species of lacewings. This study was the first to find lacewings in DPRK, expanding the geographic range of these insects and increasing the total biodiversity of lacewings in the Early Cretaceous. The discovery of the net-winged insects here suggests the Sinuiju Formation may represent similar environments to other geological formations of the same age, such as the Yixian Formation in the People’s Republic of China, the Crato Formation in Northeast Brazil, and many others. 

Broader Implications beyond this study: Finding new species of lacewings in DPRK shows that new discoveries can expand the biodiversity and biogeographic range of fossil insects, which are not commonly preserved in the fossil record. The compaction of the shale allowed for rare preservation of their delicate wings and unique features. Knowing more about how they were preserved, too, may help us identify other places where delicate organisms may have been encapsulated in sediment and fossilized. There are many more insect species waiting to be discovered, including but not limited to, lacewings!

Citation: So, & Won, C. G. (2022). A new fossil lacewing (Ithonidae) from the Lower Cretaceous (Barremian-Aptian) Sinuiju Formation, Democratic People’s Republic of Korea. Cretaceous Research, 138, 105288.

Newly discovered fossil evidence of a close relative to all animals (Animalia)

First putative occurrence in the fossil record of choanoflagellates, the sister group of Metazoa

Carolina Fonseca, João Graciano Mendonça Filho, Matías Reolid, Luís V. Duarte, António Donizeti de Oliveira, Jaqueline Torres Souza & Carine Lézin 

Summarized by Jacob Fogg, who  is a student at the University of South Florida studying geology. All his life he has been interested in the natural world and how it works. He came into USF as an undeclared major and after taking an intro environmental science course, he was hooked. Jacob hopes to work in some capacity as a geologist when he graduates from USF in 2023. 

Purpose of Study: Choanoflagellates are single celled organisms that have been found to be the closest living relative to animals that we know of. We know this because sponges, which are a part of the animal kingdom, contain cells called choanocytes that behave in the same manner as choanoflagellates. Despite knowing a great deal about these organisms and their relationship with animals, scientists have never found evidence of them in the fossil record until now. With new fossil evidence of choanoflagellates, scientists can now study the structure and function of these organisms, in relation to how they work in animals, and the environment in which they lived many years ago.

Data Used: 22 rock samples were collected from the Betic Mountain System in southern Spain. These rocks are from the Cretaceous Period, approximately 100 million years ago, when this area was a shallow sea. The samples contained a material called kerogen, which is a form of organic matter that has undergone heat and pressure. If kerogen is continuously exposed to more heat and pressure, then it will eventually become the natural gas that we use in our everyday lives. It was in the kerogen that scientists were able to find the preserved choanoflagellate fossils.

Methods: Researchers crushed up the collected samples and treated it with an acid bath to remove the rock material. Then, they concentrated the kerogen using a heavy liquid and centrifuged the kerogen (meaning, the scientists placed the samples in a machine that spun the kerogen, causing it to separate from any excess water). The kerogen was then placed on slides and examined under a microscope and exposed to white and blue florescent lights to pick out organic particles. It was here where scientists were able to find choanoflagellate fossils. The fossils were then analyzed through the process of confocal laser scanning microscopy (CLSM). This process takes microscopic photos of the samples using high resolution imaging, which can be used to create a 3D model of what you are imaging. CLSM is a very sophisticated imaging process.

Results:  Using the 3D model from CLSM (Fig. 1), scientists were able to directly observe the structure of the choanoflagellates. In the model they created, scientists could see how the choanoflagellates form colonies. The choanoflagellates do this by constructing intercellular bridges and using their filopodia (similar to antennas) to connect their cell bodies together and create a large colony. Scientists were also able to make out the cell bodies of individual choanoflagellates and their flagella (similar to tails). When analyzing the organic material of the rocks, scientists were able to find other microorganisms, such as freshwater microplankton. This suggests that the choanoflagellates in the samples collected were in freshwater environment. Now, in the future, if we find choanoflagellate fossils somewhere in the world, we can infer what type of environment was likely present when the choanoflagellates were living.

Photos A-F look like a hairy ball. The ball is composed of the individual cell bodies of the choanoflagellates which looks like smaller round structures. The hair coming from the large ball is the flagellate of the individual cells. The hairy ball is approximately 60 micrometers in diameter. That’s 0.06 millimeters!
Figure shows the 3D model of choanoflagellates constructed from CLSM. Photo A shows a choanoflagellate colony. They bind together and use their tails (flagella (flagellum singular), the wavy lines that come off of the round structure) to grab food and bring it into the colony. Photos D and F show the cell body of an individual member of the colony.

Why is this study important?  This study is important because choanoflagellates are the link between bacterial organisms and sponges, which are likely among the earliest evolved animals. This means that choanoflagellates are one of the most closely related living things to animals, despite not being animals themselves. . Understanding how these organisms form colonies and sustain themselves can give us insight into how the compare to similar cells that are contained in animal bodies. We can then get a better understanding of how animal cells work.

Broader Implications beyond this study: Now that we have fossilized evidence of choanoflagellates, we have a link between animals and eukaryotic cells. With further research, we may be able to find transitional fossils that show how choanoflagellates became incorporated into animal cells, like in sponges. 

Citation: Fonseca, C., Mendonça Filho, J. G., Reolid, M., Duarte, L. V., de Oliveira, A. D., Souza, J. T., & Lézin, C. (2023). First putative occurrence in the fossil record of choanoflagellates, the sister group of Metazoa. Scientific Reports13, 1242.

Geology from the air

By Stephen Hill and Amanda Fischer. Stephen wrote the text and Amanda provided the images.

The geology you can see from an airplane is truly spectacular- the sights of the world below have enchanted most everyone who has taken an airplane. In this post, we walk you through the geology behind some of the sights you might see from the skies going across the western United States. Next time you take a flight, look out the window and learn more about the geology all around us! 

Most people are aware that there are volcanoes in the western United States (U.S.) thanks to the frequent headlines of some of the large strato-volcanoes (e.g., more cone-shaped volcanoes, like Mt. Saint Helens) in the Cascades of Washington and of course the “doomsday” headline-maker, the Yellowstone caldera or “super-volcano.” What many folks are not aware of are the many smaller volcanic fields that dot the South-Western U.S. including Arizona and New Mexico, even though they are often responsible for some of the iconic mesas and plateaus associated with those states. The 8,000 square mile (about the area of Vermont) Raton-Clayton Volcanic Field of New Mexico is one such example. 

The first occurrence of volcanism at the Raton-Clayton Volcanic Field in New Mexico is thought to have occurred around 50 million years ago and has had sporadic eruption events to as recent as 30,000 years ago. Image 1 was taken while flying over this volcanic field. Visible in the center of the frame is a textbook example of what geoscientists call a cinder cone (or scoria cone) volcano: this one in particular is called Capulin Volcano. Cinder cones are the most common type of intraplate volcano (i.e., a volcano not located on the boundary of a tectonic plate) and are formed when fountains of lava erupt from a volcanic vent. As the lava is ejected into the air, it cools into rock and ash and begins to collect around the vent. Over a period of constant or spaced-out eruptions, this accumulation will form the cone shape you see. Capulin represents some of the younger activity in the field, estimated to be 30,000 years old which is why it retains its textbook shape–– it hasn’t yet been weathered away, like some of the older features of the field.

View from airplane of topography and some meandering rivers of light-colored rocks. In center is a cone shaped volcano.
Image 1. Raton-Clayton Volcanic Field (New Mexico, USA). In the center is the cinder cone volcano, Capulin Volcano

The older a feature is, the more time it has spent exposed to the weathering processes of Earth’s surface; this can drastically alter the way some volcanic features look. If we look at Image 2, we can see an expanded view of Image 1. Now, a second cinder cone is visible at the bottom of the frame. In between the two cinder cones, we can see two features that look like squiggly outlines with flat tops. These are called mesas now, and they’ve been worn down over many, many years of weathering and erosion, primarily from wind and rain. 

View from airplane of topography and some meandering rivers of light-colored rocks. In lower left corner is a cone shaped volcano. A lot of the topography has been worn down from erosion, so features are flatter than they were when they would have formed
Image 2. Another view of Capulin Volcano (lower left) in the Raton-Clayton Volcanic Field, with mesas throughout, formed from weathering and erosion

Weathering and erosion are also responsible for some of the most spectacular aerial scenery you will see over the Western US (e.g., the Grand Canyon). Visible in Image 3 is Glen Canyon, which, just like the Grand Canyon, has been cut by the mighty waters of the Colorado River. The geology of this area is primarily dominated by sandstone (i.e., Navajo & Wingate sandstones) which have been eroded by the flow of the river over the course of millions of years. The meanders of the river are cut into the sandstones and leave traces of the river’s path from years gone by: this produces many spectacular views. Viewing erosive patterns from a bird’s eye view can also help inquisitive minds better understand runoff and the creation of rivers/watersheds, as seen in Image 4.

Canyon- features formed from a river- evidence of the river is currently still there, winding around and evidence of where the river was years ago is, too, as evidenced by the rock patterns where water cut into them
Image 3. Glen Canyon, formed by water of the Colorado River
patterns of water run off cut into rocks from a bird’s eye view: water ran down the tops of higher topographic features and cut into them, leaving behind patterns of how the water moved down it.
Image 4. Patterns of erosion from wind and water movement leave behind these gorgeous views that we can appreciate from above

Using Modern Rainforests to Study Fern-Insect Interactions in the Fossil Record

Fern-Arthropod Interactions from The Modern Upland Southeast Atlantic Rainforest Reveals Arthropod Damage Insights to Fossil Plant-Insect Interactions

Summarized by: Haley Vantoorenburg is a geology major at the University of South Florida. Haley currently researches encrusting organisms on Paleozoic brachiopods and plans to work closely with fossil preparation and preservation studies in the future.

What was the hypothesis being tested (if no hypothesis, what was the question or point of the paper)? Ferns were some of the first plants to have evolved broad leaves (fronds) in the fossil record (the earliest known records are about 360 million years old). These broad leaves allow large areas of insect damage from insects present while the plant was alive to be preserved. Modern and fossil ferns can be compared against one another to understand what insect interactions were present throughout geologic time, and the ways these interactions have either changed or remained constant. 

What data were used?: This study examined 17 types of damage (grouped into categories by the method used to cause the damage or by the area of the leaf affected; see Methods below) caused by insects, using both fossil ferns from multiple collection sites and modern ferns from a rainforest in southern Brazil. Ferns were chosen because, as opposed to other plant types, their broad leaves increase access for insect predation and modern broad-leafed ferns are very similar to some of their fossil relatives. Ferns became abundant in the Carboniferous (359.2–299 Mya). In the Carboniferous, records of arthropod (spider and insect) damage to plants also became more frequent. While insects are often not preserved with the fossil ferns, the types of damage that prehistoric insects caused are very similar to the damage types observed today, even if we don’t know if the types of insects that made the damage are or aren’t similar. Because fossil ferns are so similar to their living relatives, and because ferns are one of the first broad-leaved plants, scientists can use modern ferns as models to study the oldest plant-arthropod interactions. 

Methods: This study used an area of rainforest with high humidity, many fern species, and high fern density to study modern ferns. A census of the ferns present and any records of insect-fern interactions were collected over a transitional area from the lower broad-leaf forest to the upland grassland. The damage type, richness per leaf, and damage size were recorded using hand lenses, calipers, and macroscopic and microscopic photography. Functional feeding groups (FFG) were made to categorize the types of insect damage. Damage from egg-laying and traces were also recorded. Damage was recorded using a damage type guide that described 413 different damage types. This was compared to compiled fossil fern data from many sites. 

Results: Even with 413 pre-established damage types, one new damage type was discovered in this study. This new damage type is a sub-type of surface feeding that features a series of rounded damage marks that was observed in both modern ferns and in multiple fossil ferns. Some types of damage were found rarely in modern ferns, but never in fossil ferns (hole feeding – the creation of separate holes in the leaf tissue – and galling – the development of waxy or swollen layers). Margin feeding (consuming only the edges of a leaf) was found in both fossil and modern ferns and included the most common damage types (46% of the damage observed). Surface feeding (damaging but not completely breaking through the leaf tissue) was recorded on both fossil and modern ferns (10%). Some types were found in modern and fossil plants, but some types were only found in angiosperms (i.e., flowering plants) in the fossil record and not fossil ferns (piercing and sucking, small points of damage or swollen leaf sections, 15%, and mining, creating subsurface damage, 8%). 

A bar chart with the number of observed instances on the left y-axis to match the bars and the types of functional feeding groups on the x-axis. It is overlain by a line representing the cumulative percentage. From left to right: Margin feeding, 220 instances and 46% of the total. Piercing-and-sucking, 73 instances, the cumulative total 61%. Hole feeding, unlabeled but about 52 instances, 72% the cumulative total. Surface feeding, 50 instances and 83% of the cumulative total. Mining, unlabeled but around 40 instances, 91% of the cumulative total. Hole feeding, 34 instances, 98% of the cumulative total. Galling, nine instances, 100% of the cumulative total.
Figure: A bar chart of the recorded damage types by functional feeding group, showing the dominance of margin feeding in the modern ferns in the Sao Francisco de Paula National Forest, municipality of Sao Francisco de Paula, Rio Grande do Sul, southern Brazil.

Why is this study important?: This study showed that modern ferns can provide a better understanding of the marks that different insect feeding methods cause and of the fossil record of these marks on similar ferns. Researchers found that the levels of precipitation impacted the amount and types of fern-insect interactions in modern ferns. This means that studying modern ferns can create models for studying past environmental conditions using fossil fern data. Additionally, there are fossil and modern instances of insect interactions that show a specialized association with specific ferns.

Broader Implications beyond this study: The similar rates of predation by insects on both modern and fossil plants show that ferns were important to herbivorous (plant-eating) arthropods throughout history. All FFGs identified in the fossil record were found in modern ferns, so understanding interactions in modern environments can be used to determine the environmental conditions of different fossil assemblages, such as the projected precipitation level of their environment. The prevalence of fern-arthropod interactions throughout history means that it can be used to study changes in these fern-arthropod relationships in geologic time and we may be able to use them to model the influence of climate change. 

Citation: Cenci, R., & Horodyski, R. S. (2022). Fern-Arthropod Interactions from the Modern Upland Southeast Atlantic Rainforest Reveals Arthropod Damage Insights to Fossil Plant-Insect Interactions. Palaios, 37(7), 349–367.

How the ability to swim affects crinoid arm regrowth rates

Ability to Swim (Not Morphology or Environment) Explains Interspecific Differences in Crinoid Arm Regrowth

Biography: Delaney Young. She is an undergraduate student at the University of South Florida. She is currently working on her geology B.S. and will graduate in the summer of 2023. She then plans to obtain her geology M.S. starting in the Spring of 2024. 

Point of the Paper: The main point of the paper was to determine how arm regeneration rates of feather stars (occurring after injuries), a kind of crinoid, vary. Scientists examined the swimming ability of crinoid species, available food supply, severity of the injury, water temperature, number of regenerated arms, and the total number of arms in order to understand what drives differences in regeneration rates. The authors of this study found that the swimming crinoids regenerated arms up to three times faster than non-swimming crinoids. 

What data were used? 123 adult feather starts from eight different species were collected at depth in the ocean during two sessions (December 2016 – April 2017 and June – October 2018) in Malatapay, Negros Oriental, Philippines. The respective maximum arm length, the maximum number of arms, and the arm regeneration were compared. 

Methods. To study the rates of arm regeneration amongst swimming and non-swimming crinoids, the animals were collected at depths ranging from 5 to 35 meters. In the 2016 expedition, the individuals were captured and had a few arms removed by researchers. The researchers would pinch a feather star’s arm until it was voluntarily released as a means for amputation. The mechanism of voluntary release is used as protection for the crinoids. Researchers caused the crinoids to amputate an average of 3–5 arms, but some amputated up to ten arms. The animals were brought back to their original habitat after they amputated their arms and scientists measured their regrowth rates. In the 2018 expedition, the animals were caught and put in bamboo cages with mesh material on every side. The mesh allowed food particles to enter the cage, and the cage dimensions allowed the feather stars with the longest arms to extend them to the fullest. To mark a starting point for every animal, the measurements of maximum arm length and maximum arm number were taken for each feather star. The swimming or non-swimming ability of eight species from Malatapay, Negros Oriental, Philippines, was recorded and compared to the respective maximum arm length, the maximum number of arms, and the arm regeneration rate. 

Results. Of the eight tropical feather stars collected in Malatapay, Philippines, the rate of arm regeneration ranged from 0.29–1.01 mm/day (Figure 1). The species included two swimming and six non-swimming feather stars. The swimming feather stars experienced regeneration rates of 0.89–1.01 mm/day. The lower of the two rates (0.89 mm/day) was higher than the highest non-swimming arm regeneration rate. The impacts of total arm number and total regenerating arm number on rates of regeneration were larger in non-swimmers than in swimmers. There was no notable relationship between the number of removed arms and the rate of regrowth.

Image showing a graph of arm regeneration rates by color-coded species of feather star, with regenerating arm length on the y-axis and time on the x-axis. The image shows the arm length (millimeters) over time (days) and the mean regeneration rate of eight tropical feather stars. The six non-swimming feather stars of Family Comatulidae (Anneissia bennetti, Capillaster multiradiatus, Clarkcomanthus mirabilis, Comaster nobilis, Comatella nigra, Phanogenia gracilis) are shown in shades of blue. The one swimming family Mariametridae (Oxymetra cf. erinacea, Stephanometra indica) is shown in shades of red, orange, and yellow. The 95% confidence interval of each curve is shown in gray. Oxymetra cf. erinacea and Stephanometra indica show higher rates of growth.
Figure 1: Modified from Stevenson et al. (2022). This graph depicts the arm regeneration rates per species used in this study. Swimming crinoids showed higher rates of regeneration than non-swimming crinoids.

Why is this study important? The researchers found that swimming ability alone best explains the differences in arm regeneration rates amongst the swimming and non-swimming feather stars. Swimming ability in feather stars is thought to be an adaptation from the need to escape predators that live on the seafloor. Feather stars that lost limbs while escaping predators would need to regrow limbs quickly, as having missing limbs would negatively affect the animal’s ability to escape predators in the future. The rate of regeneration, while controlled primarily by swimming ability, is still affected by temperature, but to a lesser degree. In cold water, biological processes slow down, so crinoids in cooler waters with other forms of protection would have had better chances at survival. Scientists could relate this to the way that fossilized crinoids look to help understand the environment they lived in.

Broader implications. This paper can be related to paleontology because knowing if a crinoid was swimming or non-swimming can inform scientists of the likely regeneration rate of arms of organisms in the fossil record. Knowing these pieces of information can potentially give researchers more clues about the predation pressures that a fossil crinoid may have faced. We could hypothesize, for example, that crinoids in cooler waters may have had other forms of protection or retrieval, as a survival mechanism for the slowed biological processes caused by cooler water. The results of this paper could be compared to fossilized crinoids, so researchers can understand the ancient marine environments and ecology of crinoids. 

Citation: Stevenson, A., Corcora, T. C. Ó., Harley, C. D. G., & Baumiller, T. K. (2022). Ability to Swim (Not Morphology or Environment) Explains Interspecific Differences in Crinoid Arm Regrowth. Frontiers in Marine Science, 8. 

Meet the Museum: Alexander Koenig Zoological Research Museum

Figure 1: This large diorama showcases elephants, zebras, lions, baboons, guinea fowl and much more, all in natural poses. The longer you wander around and look at it, the more you discover.

Linda and guest blogger Blandine here, for a little museum visit report! 

Figure 2: Deep in the tropical jungle you find these two chimps, a grown up and a baby, hidden between the bushes. A video is projected on the floor nearby, showing typical chimpanzee behavior.

Last year we visited the Alexander Koenig Zoological Research Museum or Museum Koenig for short,  located in Bonn, Germany. The museum is part of the Leibniz Institute for the Analysis of Biodiversity Change

Its main focus is the rich, high-quality taxidermy collection used to educate people about animals and their habitats, as well as environmental issues. The collection is also – as the name and affiliation of the museum implies – heavily used for biodiversity and zoology research. The museum was named after its founder Prof. Alexander Koenig, who worked on zoology with an expertise in bird biodiversity in the 19th and early 20th century. The museum still hosts many specimens that were collected by Koenig himself (for example two giraffes and many bird eggs).

Upon entering the building, visitors are greeted by a quite impressive diorama of African savanna fauna and flora ensembles, with naturalized pieces in dynamic poses (Fig. 1). Each animal seems almost alive, with real water dripping out of  the mouth of a zebra drinking in a pond, while a leopard bites an antelope’s throat. 

Figure 3: The desert room not only exhibits taxidermied animals, but also has a strong focus on geology related topics, for example it explains how dunes form and wander. Visitors are also encouraged to investigate different sands under the microscope to discover the diversity of sediments!

In addition to telling interesting stories, the diorama scenes allow the spectators to learn more about animals’ habits and behaviors. Often, audio tracks of both animal and environmental sounds are played in the background and many information sheets and panels (in German and English) are displayed on a variety of scientific topics. 

Figure 4: This exhibit on the history of the museum hosts a large variety of specimens, all of them older than 100 years! This includes a taxidermied pelican, the skull of a giraffe, several european fishes, sand boas, a beaver skeleton and much more.

In the next room you find yourself in a tropical jungle, where light effects play a huge role in the display of the naturalized specimens (Fig. 2). Here, the interactions between animals, plants and their environment are the main focus of the dioramas. The extremely realistic appearance of plants inside the cases is fascinating, as each and every of the hundreds of thousands leaves and twigs are actually plastic replicas that were hand painted by skilled artists, no two leaves are the same. In the dark forest, you can sit and watch short documentaries about apes or listen to an audio guide explaining interactions between ants and mushrooms in the tropical forests. The day we visited, on the first floor, we couldn’t visit the canopy of the rainforest, as the displays were still under construction. It has since then been opened to the public: A massive forest canopy diorama and multiple activities educating visitors further about the impact humans have on the rainforest, and people taking action to protect it. 

Figure 5: The interactive ‘consumer’s table’ allowing visitors to see the effects of their lifestyle choices immediately.

The museum then takes you along on a trip around the world, from Antarctica (seemingly the oldest part of the permanent exhibition, that maybe needs to be updated a little bit from a public outreach point of view, especially when compared to the brilliantly done new tropical forest exhibition) to the deserts, which has surprising and very educative, interactive displays (Fig. 3).

A substantial part of the permanent exhibition is dedicated to the history of the museum and the problems associated with it (e.g. colonialism), and its historic specimens (Fig. 4). This section also tackles the role of humans in the disappearance of species and the destruction of natural habitats. These themes, along with other important topics such as climate change, are brought up in several instances all across the museum. Visitors are invited to sit at the ‘consumer’s table’ interactive display, a great (but also eye-opening and saddening) tactile table with graphic representations that estimate and illustrate your use of natural resources and your impact as a consumer on deforestation. As you select lifestyle choices such as updating your phone for the newest model, selecting a car or public transport, choosing exotic woods over locally produced items, selecting your food choices, you can watch the forest deteriorate or heal with every choice you make (Fig. 5). On the other side of the first floor is an exhibition dedicated to the beautiful and colorful world of insects (Fig. 6). This area also gives insights into research work including an interactive exhibit of a taxonomist’s lab, including microscopes, maps, games and many many books. 

Figure 6: A large number of beetles are shown in this exhibit, of which we only captured this small section to showcase the diversity in color and shapes that beetles can have! Beetles are the most diverse order of animals on this planet, roughly ¼ of all living animal species discovered so far are beetles!

Then, there’s the more ‘ancient’ part of the collection, displaying naturalized specimens in glass cases with a systematic approach (for example showing a large number of birds together regardless of their habitat), and some more amazing, though old, dioramas that transport you to the seaside, into the forest or into a field, with a focus on the local german fauna. 

Figure 7: A replica based on the CT-scans of a Eurohippus specimen from Messel. This way of presenting it allows the visitors to look at the specimen from all sides.

The museum’s top floor is dedicated to temporary exhibitions. At the time of our visit, one side consisted of a huge photograph exhibition, highlighting the beauty of nature through the seasons. The other side was dedicated to an exhibition showcasing horse evolution and especially the eocene horses of the Messel pit (Fig. 7). The main element of this exhibition was an exquisitely preserved specimen of Eurohippus; an extinct genus of a relative of modern horses, discovered in Messel. The Messel pit is an eocene maar lake in which hundreds of fossils from a large range of plant and animal species have been preserved exceptionally well  (a location comparable in age, fossil assemblage, environmental conditions and depositional setting as the Eckfelder Maar we already wrote about, though much larger)  – including several specimens of Eurohippus –  allowing paleontologists to have a good insight into these extinct animals’ biology and life. Several specimens have been preserved so well, their internal organs could be investigated and at least 6 specimens are known to have been pregnant when they died. 

In this exhibit, Eurohippus was shown both as a replica of a fossil, as well as as a reconstructed version.  An entirely white model was used as a canvas, the visitors could play with different patterns and colors of light being projected on the model, mimicking extant animals’ fur patterns to show possible colorations the extinct horse relatives could have had. As the color and patterns of Eurohippus’ fur is still a mystery, this is still up to imagination (Fig. 8).

Figure 8: Visitors could project a variety of coat patterns onto a white Eurohippus model, here we set it to resemble the coat of a baby tapir, but many other stripes, spots, shadings and colors were possible. This exhibit was not only meant to be interactive but also to show the general public that certain properties shown in reconstructions are educated guesses rather than facts.

One of the previous temporary exhibitions of the Museum Koenig was called ‘Big, bigger, dinosaurs’, and because this was not only very cool, but our local paleontological preparator Blandine also got to help dismantle it in the end, we will cover this exhibition in a separate post very soon! Until then, you can already find a post on her instagram about the dismantling (together with a large range of various dinosaur-related content) @dinosaur_forensics 

A bit more than half of the informative text appearing on screens and panels in the permanent exhibition is also available in English, as well as much of the audio and video content. Apparently, the museum is working on translating their content from German as they redesign display areas. 

In addition to their efforts in making the museum accessible to english-speaking, we also noticed a large amount of available seating throughout all of the rooms, lifts in addition to stairs, and playing areas for children, making the museum a very welcoming environment. 

We highly recommend a visit! 

Here are some more impressions of our visit (Figs. 9-12):

Figure 9: Visitors were encouraged to compare the digits of a variety of small reptiles in this exhibit. Some geckos (on the right) have wide and flat finger and toe tips while fringe-fingered lizards (bottom left) have – you guessed it – fringed fingers and toes.


Figure 10: This Pleistocene Irish elk (Megaloceros giganteus) greets visitors upon entering the building. Irish elk were first described by Irish researchers, but have since been found in many places ranging from western Europe to central Russia.


Figure 11: The tropical jungle diorama is so incredibly detailed, they even included individual ants, or in this case an Orb-weaver spider in its web.


Figure 12: Since this is a zoological museum, only few exhibits focus on extinct species. This replica of one of the world’s largest ammonites (Parapuzosia seppenradensis) was quite impressive, so Blandine decided to pose next to it. Most of the biggest ammonites ever found have been discovered in the vicinity of the city of Münster in Germany!

How evolutionary analysis results in bowfins show species diversity and lineages of a ‘living fossil’

Phylogenomic analysis of the bowfin (Amia calva) reveals unrecognized species diversity in a living fossil lineage

Summarized by Colton Conrad, a proud geology major at the University of South Florida. He is a senior who is as a geologist at ASRus (Aquifer Storage Recovery). Colton’s life revolves around fishing, hunting, exercising, and creating things out of metal. He is a great taxidermist and a fine creator of swords and shields.

Hypothesis: The purpose of this paper is to categorize bowfins into evolutionary groups by collecting samples to determine their diversity and evolutionary history.

Data: The data here is a collection from 94 individual bowfins found from the eastern United States. From phylogenetic analysis, which is a way of understanding species evolution from genetic data, the researchers involved with this project were able to find and sort out genetic variations in the DNA of the bowfin known as SNPs (single nucleotide polymer) to determine which species were most closely related. The sorting of SNPs is finding nucleotides that have changed but are still found in the population. They used specific lengths of DNA to define changes in the four nucleotides (adenine, cytosine, guanine, and thymine (A, C, G, and T)) in bowfin lineages and to find diversity among the population. 

Methods: Scientists ran the data using evolutionary tree computer programs to find the most supported configurations of bowfin relationships. Figure 1 shows the evolutionary reconstructions and the genomes from bowfins after comparing the phylogenetic population structure in bowfins. The researchers also ran a bootstrap analysis to test the likelihood of their results. Bootstrapping means that the analysis is re-run multiple times and the number of times the original answers are returned is counted as a percentage (e.g., the bootstrap support is 100% when the same tree structure is returned 100 times). 

Figure one is a circular chart showing the relations and patterns in the bowfin as an evolutionary tree. The four different colors red, blue, green, and yellow show the different species clusters. The larger dots colored green represents 100% bootstrapping, and the descending gray dots represent the percentage getting lower.


Results: The results of this study have revealed species diversity of bowfins populations (Figure 2). By analyzing SNP of the bowfins from all the locations the study revealed diversity in the population by showing the molecular and genetic data collected from these species can be traced back to two species of prehistoric fossil bowfins. This means that at least two bowfin species from this study are quite similar to the fossil forms and are considered ‘living fossils’

Why this study is important? This study is important because it gives us insight into what prehistoric fish species were like and how other species may have evolved to give us the diversity we see today. 

Broader Implications beyond this study: This study has added an deeper perspective to the DNA variations found in bowfin to help understand evolutionary adaptations found in soft ray fined fish, helping in our understanding of modern fish and terrestrial species. 

Figure two is a picture of the diversity of bowfins collected from the study. The bowfins in this figure vary in color based on environmental surroundings. Species A is a lighter brown color with reddish fins and a white belly. Species B is darker brown with a tan belly. Finally, species C is a blackish green color with a lime-colored belly. The fins, gills, and body types are all the same. The dorsal fins of the bowfin are a long soft ray design with a large, rounded tail. The pectoral fins are small compared to the body’s size and are rounded shape much like the other fins. This image shows what a bowfin looks like and gives a visual into the diversity of bowfin.

Citation: Wright, J., Bruce, S., Sinopoli, D., Palumbo, J., & Stewart, D. (2022). Phylogenomic analysis of the bowfin (Amia calva) reveals unrecognized species diversity in a living fossil lineage. Scientific Reports, 12, 1–10.