Saturday, December 10, 2022

Wildlife disease ecologist launches project to help DoD monitor quality of bird habitats on military installations


Metabarcoding and bioinformatics expertise key to technology transfer

Grant and Award Announcement

NORTHERN ARIZONA UNIVERSITY

NAU wildlife disease ecologist Jeff Foster 

IMAGE: ASSOCIATE PROFESSOR JEFF FOSTER (RIGHT) OF NORTHERN ARIZONA UNIVERSITY’S DEPARTMENT OF BIOLOGICAL SCIENCES AND THE PATHOGEN AND MICROBIOME INSTITUTE (PMI) WAS RECENTLY AWARDED A GRANT BY THE DOD FOR A NEW STUDY, “DEMONSTRATION OF METABARCODING FOR MONITORING BIRD SPECIES HABITAT QUALITY ON DOD INSTALLATIONS.” view more 

CREDIT: NORTHERN ARIZONA UNIVERSITY

The U.S. Department of Defense (DoD) owns military installations on nearly 27 million acres all over the country—roughly equivalent in size to the State of Virginia—and oversees these lands through a network of natural resource managers. According to the DoD, the program supports “the military's testing and training mission by protecting its biological resources… and working to ensure the long-term sustainability of our nation’s priceless natural heritage.” One of the program’s top priorities is monitoring and maintaining populations of threatened and endangered species (TES) of birds—especially those that eat insects and other arthropods like spiders, which have been particularly hard hit.

Monitoring the quality of the birds’ habitats, which includes their typical diets of insects, is one of the most important ways scientists investigate declining bird populations. The tools the military land managers use to assess diets and habitats are critical, but the current methods of measuring habitat quality related to the birds’ food resources are time consuming, expensive and require specific biological expertise.

To this end, associate professor Jeff Foster of Northern Arizona University’s Department of Biological Sciences and the Pathogen and Microbiome Institute (PMI) was recently awarded a grant by the DoD for a new study, “Demonstration of Metabarcoding for Monitoring Bird Species Habitat Quality on DoD Installations.” This three-year, $900,000 project will focus on five insectivorous species on four military sites:

  • Golden-cheeked Warbler (Setophaga chrysoparia) and Black-capped Vireo (Vireo atricapilla) at Fort Hood, Texas
  • Least Bell’s Vireo (Vireo bellii pusillus) at Camp Pendleton, California
  • Golden-winged Warbler (Vermivora chrysoptera) at Fort McCoy, Wisconsin
  • Oahu Elepaio (Chasiempis ibidis) at Schofield Barracks, Hawaii

Advanced approach focuses on bioinformatics, metabarcoding

Metabarcoding is a technique that enables scientists to identify multiple species of plants or animals on a large scale based on rapid, high-throughput environmental DNA sequencing, which represents a huge technological step forward.

“We’ll assess habitat quality by using advanced genetic approaches to measure arthropod food resources in bird diets and from the vegetation on which these birds forage,” Foster said. “Our three primary objectives are to demonstrate the effectiveness of metabarcoding of bird diets and food resources; compare this genetic approach to conventional approaches that employ visual identification of arthropods using microscopes; and provide user-friendly guidance to military land managers so they can understand the process and use this approach for monitoring in the future.”

“The bioinformatics can be challenging and daunting if you're first getting into DNA metabarcoding, so we’ll provide an established workflow that we can share with the land managers,” he said. The team will collect fecal samples from the birds (bird poop) as well as arthropod samples, perform bioinformatic and chemical composition analyses, validate the technology by comparing it to conventional methods and develop guidance documents and lead hands-on technical workshops for the military land managers. “We’ll be conducting the most in-depth diet analysis of birds on military installations done to date.”

Foster brings his expertise as well as that of PMI to the project. “There’s much more to metabarcoding work than simply sequencing a gene. And here’s where our team excels. We use tools developed over the past 13 years for analyzing the human microbiome. Many of these tools have been developed by NAU professor Greg Caporaso and his team at PMI, so we have considerable technical expertise in analyses including understanding reference libraries of sequences and developing the analytical software.”

Collaborators include military scientists and undergraduate researcher

Foster will work closely with co-principal investigators Jinelle Sperry and Aron Katz from the U.S. Army Corps of Engineers Engineer Research and Development Center’s Construction Engineer Research Laboratory as well as with collaborators at each of the installations.

NAU undergraduate researcher Hannah Brosius is working on the project with Foster and PMI researcher Alexandra Gibson. Brosius, who will be assisting with the lab work and analyses, said, "I'm excited about this project because the analysis of bird diets from feces will help us figure out why these endangered birds might be at risk. It’s fun to be able to take a fecal sample from a species; you can learn a lot using DNA to understand how an animal lives."

She is looking forward to her future as a veterinarian. "I’m interested in lab work, which allows me to focus on a project and have results quickly. This research experience will be important for veterinary school and will expand my understanding of biology."

Project to benefit TES monitoring across DoD sites

The project’s outcomes will have multiple benefits that will help DoD land managers monitor threatened and endangered species. “It’s an effective and cost-efficient way to measure habitat quality,” Foster said, “particularly as it relates to a key factor regulating insectivorous bird abundance—arthropod food resources. The technology can be deployed at any DoD site where understanding diet or habitat quality is necessary for TES monitoring of vertebrate taxa. Population surveys can assess the current abundance and distribution of TES but determining the specific factors limiting their populations adds additional complexity. This method will not only give DoD natural resource managers the ability to distinguish poor versus high quality habitat, but will provide critical information about restoration, habitat recovery from disturbance and a baseline of prey availability should arthropod populations decline regionally in the future.”

In addition, “numerous other bird species are on the list of DoD Priority Species that could benefit from this technology as well as other taxa such as amphibians, reptiles and small mammals,” he said.

About Northern Arizona University

Founded in 1899, Northern Arizona University is a community-engaged, high-research university that delivers an exceptional student-centered experience to its nearly 28,000 students in Flagstaff, at 22 statewide campuses and online. Building on a 123-year history of distinctive excellence, NAU aims to be the nation’s preeminent engine of opportunity, vehicle of economic mobility and driver of social impact by delivering equitable postsecondary value in Arizona and beyond. NAU is committed to meeting talent with access and excellence through its impactful academic programs and enriching experiences, paving the way to a better future for the diverse students it serves and the communities they represent. 

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21ST CENTURY ALCHEMY

Microbial miners could help humans colonize the moon and Mars

UCI and Johns Hopkins researchers uncover mineral modification through biology

Peer-Reviewed Publication

UNIVERSITY OF CALIFORNIA - IRVINE

Irvine, Calif., Dec. 8, 2022  The biochemical process by which cyanobacteria acquire nutrients from rocks in Chile’s Atacama Desert has inspired engineers at the University of California, Irvine to think of new ways microbes might help humans build colonies on the moon and Mars.

Researchers in UCI’s Department of Materials Science and Engineering and Johns Hopkins University’s Department of Biology used high-resolution electron microscopy and advanced spectroscopic imaging techniques to gain a precise understanding of how microorganisms modify both naturally occurring minerals and synthetically made nanoceramics. A key factor, according to the scientists, is that cyanobacteria produce biofilms that dissolve magnetic iron oxide particles within gypsum rocks, subsequently transforming the magnetite into oxidized hematite.

The team’s findings, which are the subject of a paper published recently in the journal Materials Today Bio, could provide a pathway for new biomimetic mining methods. The authors also said they see the results as a step toward using microorganisms in large-scale 3D printing or additive manufacturing at a scale that’s useful in civil engineering in harsh environments, like those on the moon and Mars.

“Through a biological process that has evolved over millions of years, these tiny miners excavate rocks, extracting the minerals that are essential to the physiological functions, such as photosynthesis, that enable their survival,” said corresponding author David Kisailus, UCI professor of materials science and engineering. “Could humans use a similar biochemical approach to obtain and manipulate the minerals that we find valuable? This project has led us down that pathway.”

The Atacama Desert is one of the driest and most inhospitable places on Earth, but Chroococcidiopsis, a cyanobacterium found in gypsum samples collected there by the Johns Hopkins team, has developed “the most amazing adaptations to survive its rocky habitat,” said co-author Jocelyne DiRuggiero, associate professor of biology at the Baltimore university.

“Some of those traits include producing chlorophyll that absorbs far-red photons and the ability to extract water and iron from surrounding minerals,” she added.

Using advanced electron microscopes and spectroscopic instruments, the researchers found evidence of the microbes in the gypsum by observing how the very minerals contained within were transformed.

“Cyanobacteria cells promoted magnetite dissolution and iron solubilization by producing abundant extracellular polymeric substances, leading to the dissolution and oxidation of magnetite to hematite,” DiRuggiero said. “Production of siderophores [iron-binding compounds generated by bacteria and fungi] was enhanced in the presence of magnetite nanoparticles, suggesting their use by the cyanobacteria to acquire iron from magnetite.”

Kisailus said the way the microorganisms process metals in their desolate home made him think about our own mining and manufacturing practices.

“When we mine for minerals, we often wind up with ores that may present challenges for extraction of valuable metals,” he said. “We frequently need to put these ores through extreme processing to transform it into something of value. That practice can be monetarily and environmentally costly.”

Kisailus said he is now pondering a biochemical approach using natural or synthetic analogs to siderophores, enzymes and other secretions to manipulate minerals where only a large mechanical crusher currently works. And taking a leap from here, he said there could also be a way to get microorganisms to employ similar biochemical capabilities to produce an engineered material on demand in less-than-convenient locations.

“I call it ‘lunar forming’ instead of terraforming,” Kisailus said. “If you want to build something on the moon, instead of going through the expense of having people do it, we could have robotic systems 3D-print media and then have the microbes reconfigure it into something of value. This could be done without endangering human lives.”

He added that humans don’t always need to use Edisonian approaches to figure out how to do things.

“This is the main theme of my Biomimetics and Nanostructured Materials Lab. Why try to reinvent the wheel when nature’s perfected it over hundreds of millions of years?” Kisailus said. “We just have to extract the secrets and blueprints for what nature does and apply or adapt them to what we need.”

This project was funded by the Army Research Office and was aided by instruments made available by the Department of Energy’s Office of Science. The research team also included Wei Huang, a postdoctoral scholar in Kisailus’ lab group; Taifeng Wang, Ph.D., who recently graduated from UCI and is now employed at Intel; and Cesar Perez-Fernandez in Johns Hopkins University’s Department of Biology.

About the University of California, Irvine: Founded in 1965, UCI is a member of the prestigious Association of American Universities and is ranked among the nation’s top 10 public universities by U.S. News & World Report. The campus has produced five Nobel laureates and is known for its academic achievement, premier research, innovation and anteater mascot. Led by Chancellor Howard Gillman, UCI has more than 36,000 students and offers 224 degree programs. It’s located in one of the world’s safest and most economically vibrant communities and is Orange County’s second-largest employer, contributing $7 billion annually to the local economy and $8 billion statewide. For more on UCI, visit www.uci.edu.

Media access: Radio programs/stations may, for a fee, use an on-campus ISDN line to interview UCI faculty and experts, subject to availability and university approval. For more UCI news, visit news.uci.edu. Additional resources for journalists may be found at communications.uci.edu/for-journalists.

Researchers identify elusive carbon dioxide sensor in plants that controls water loss

Surprised biologists discover how two proteins work together to form long-sought plant water loss-regulating sensor, carrying implications for trees, crops and wildfires

Peer-Reviewed Publication

UNIVERSITY OF CALIFORNIA - SAN DIEGO

Plant sensor structure 

IMAGE: WORKING WITH COLLEAGUES IN THE DEPARTMENT OF CHEMISTRY AND BIOCHEMISTRY, UC SAN DIEGO BIOLOGISTS UNRAVELED THE PREDICTED STRUCTURE OF THE NEWLY DISCOVERED PLANT CARBON DIOXIDE SENSOR. THE LEFT SECTION (A) DEPICTS THE MPK4 – HT1 COMPLEX (MPK HIGHLIGHTED IN RED; HT1 IN BLUE) AND THE RIGHT (B) SECTION REVEALS THE MPK12 – HT1 COMPLEX. THE HIGHLIGHTED AMINO ACID RESIDUES (YELLOW, GREY, LIGHT BLUE AND GREEN) SHOW MUTATIONS THAT DISRUPT THE SENSOR FUNCTION. view more 

CREDIT: MCCAMMON LAB, UC SAN DIEGO

More than 50 years, ago researchers discovered that plants can sense carbon dioxide (CO2) concentrations. As CO2  levels change, “breathing” pores in leaves called stomata open and close, thus controlling evaporation of water, photosynthesis and plant growth. Plants lose more than 90% of their water by evaporation through stomata. The regulation of stomatal pore openings by CO2 is crucial for determining how much water plants lose, and is critical due to increased carbon dioxide effects on climate and water resources in a warming world.

But identifying the carbon dioxide sensor and explaining how it operates within plants has remained a longstanding puzzle.

Using a mix of tools and research approaches, scientists at the University of California San Diego recently achieved a breakthrough in identifying the long-sought CO2 sensor in Arabidopsis plants and unraveled its functioning parts. UC San Diego project scientist Yohei Takahashi, School of Biological Sciences Distinguished Professor Julian Schroeder and their colleagues identified the CO2 sensor mechanism and detailed its genetic, biochemical, physiological and predicted structural properties. Their results are published December 7 in Science Advances.

Since the stomatal pores control plant water loss, the sensor is vital for water management and holds implications for climate-induced drought, wildfires and agricultural crop management.

“For each carbon dioxide molecule taken in, a typical plant loses some 200 to 500 water molecules to evaporation through the stomatal pores,” said Schroeder, Novartis Chair and faculty member in the Department of Cell and Developmental Biology. “The sensor is extremely relevant because it recognizes when COconcentrations go up and determines how much water a plant loses as carbon dioxide is taken in.”

One critical surprise from the new research was the composition of the sensor. Rather than tracing it to a single source or protein, the researchers found that the sensor operates through two plant proteins working together. These were identified as 1) a “high leaf temperature1” protein kinase known as HT1 and 2) specific members of a mitogen-activated protein kinase family, or “MAP” kinase enzyme, known as MPK4 and MPK12.

“Our findings reveal that plants sense changes in CO2 concentration by the reversible interaction of two proteins to regulate stomatal movements,” said Takahashi, who is now based at the Institute of Transformative Bio-Molecules, Japan. “This could provide us a new plant engineering and chemical target towards efficient plant water use and CO2 uptake from the atmosphere.”

The team’s findings, which have been filed in a UC San Diego patent, could lead to innovations in efficient water use by plants as CO2 levels rise.

“This finding is relevant for crops but also for trees and their deep roots that can dry out soils if there’s no rain for long periods, which can lead to wildfires,” said Schroeder. “If we can use this new information to help trees respond better to increases in CO2 in the atmosphere, it’s possible they would more slowly dry out the soil. Similarly, the water use efficiency of crops could be improved—more crop per drop.”

To further explore their sensor discovery, the researchers collaborated with graduate student Christian Seitz and Professor Andrew McCammon in the Department of Chemistry and Biochemistry. Using cutting-edge techniques, Seitz and McCammon created a detailed model of the intricate structure of the sensor. The model implicated areas where genetic mutations have been known to restrict the ability of plants to regulate transpiration in response to carbon dioxide. The new imagery showed that the mutants cluster in an area where the two sensor proteins, HT1 and MPK, come together.

“This work is a wonderful example of curiosity-driven research that brings together several disciplines—from genetics to modeling to systems biology—and results in new knowledge with the ability to aid society, in this case by making more robust crops,” said Matthew Buechner, a program director in the U.S. National Science Foundation’s Directorate for Biological Sciences, which supported the research.

The paper’s full author list: Yohei Takahashi, Krystal Bosmans, Po-Kai Hsu, Karnelia Paul, Christian Seitz, Chung-Yueh Yeh, Yuh-Shuh Wang, Dmitry Yarmolinsky, Maija Sierla, Triin Vahisalu, J. Andrew McCammon, Jaakko Kangasjarvi, Li Zhang, Hannes Kollist, Thien Trac and Julian I. Schroeder.

HOLD THAT TIGER

Assessing El Niño ‘flavors’ to unravel past variability, future impact

Peer-Reviewed Publication

UNIVERSITY OF HAWAII AT MANOA

El Niño flavors 

IMAGE: SEA-SURFACE TEMPERATURE (SST; SHADING) AND PRECIPITATION (PRCP; CONTOURS) ANOMALIES DURING THE THREE PEAK MONTHS OF (A) EASTERN PACIFIC (EP), (B) CENTRAL PACIFIC (CP) AND (C) COASTAL (COA) EL NIÑO EVENTS. COLORED CIRCLES INDICATE CHARACTERISTIC LOCATIONS OF PROXY RECORDS, WITH DEEPER COLORS INDICATING STRONGER PRECIPITATION RESPONSE TO EACH ENSO FLAVOR (BROWN FOR DRIER, BLUE FOR WETTER). view more 

CREDIT: KARAMPERIDOU AND DINEZIO (2022)

As with many natural phenomena, scientists look to past climate to understand what may lie ahead as Earth warms. By assessing so-called ‘flavors’ of El Niño events in past climate records and model simulations, researchers have a clearer picture of El Niño patterns over the past 12,000 years and are able to more accurately project future changes and impacts of this powerful force. The study, by scientists at the University of Hawai‘i at Mānoa and University of Colorado Boulder, was published recently in Nature Communications.

“We used a unique set of climate model simulations that span the Holocene, the past 12,000  years, and accounted for changes in the frequency of El Niño flavors, the three preferred locations in which the peak of warming during different El Niño events occur—eastern Pacific, central Pacific, and coastal,” said Christina Karamperidou, lead author of the study and associate professor of atmospheric sciences at the UH Mānoa School of Ocean and Earth Science and Technology (SOEST). “Doing this allowed us to reconcile conflicting records of past El Niño behavior.”

El Niño is the primary factor affecting variability in water temperature and trade wind strength in the Pacific. Typically, researchers look for indicators of El Niño events in ancient, preserved material such as coral skeletons, Peruvian mollusk shells or lake sediment from the tropical Andes because locked within are indicators of past temperature and rainfall across Pacific.

“However, depending on where the samples are taken from—eastern Pacific, central Pacific, or near the South American coast—the frequency of El Niño events appears to exhibit different patterns,” said Karamperidou. “Records from the eastern Pacific show an intensification of El Niño activity from early to late Holocene, while records from the central Pacific show highly variable El Niño throughout the Holocene.”

The new set of climate model simulations developed by Karamperidou and co-author Pedro DiNezio, associate professor at the University of Colorado Boulder, are the first to allow the study of changes in the frequency of El Niño flavors during the past 12,000 years. This enabled the researchers to test a hypothesis that Karamperidou and colleagues posed in 2015—that paleoclimate records across the Pacific could be explained by changes in El Niño flavors.

“Indeed, we showed that Eastern Pacific events have increased in frequency from early to late Holocene, while Central Pacific and Coastal events have decreased in frequency, resulting in changes in the hydroclimate in the tropical Pacific,” said Karamperidou. “Importantly, we showed that it is not only their frequency, but also the strength of their impact that changes, which is important for interpreting records of past climate.”

Surprising impact of coastal El Niño

Additionally, this is the first study into the response of coastal El Niño events to climate changes. During these events the sea surface warming is confined off the coast of South America while the conditions in the rest of the Pacific basin are normal or colder than normal.

“These coastal events have supersized impacts with severe flooding and disasters in countries like Peru and Ecuador,” said Karamperidou. “In fact, we showed in another recent paper that even though these events are not felt around the globe like the more widely known Eastern and Central Pacific events, a better understanding of the mechanisms that drive them is essential for understanding the drivers of the other two flavors, as well.”

Freshwater stream in Hilo, Hawai‘i.

CREDIT

Pascal Debrunner via Unsplash.

Connections to Hawai‘i’s rainfall, hazards  

El Niño events have significant impacts on Hawai‘i’s rainfall, trade wind strength, the probability of hurricane formation and drought, and the type of El Niño event matters for these impacts.

“This information is important for water resource managers among others to better prepare for Hawai‘i regional climate,” said Karamperidou. “So, it is imperative that we gain a better understanding of the mechanisms of these flavors, and also improve their representation in climate models and assess their projected changes under future climate conditions.”

This work offers new knowledge on how El Niño may respond to climate change and thus can help reduce these uncertainties in global climate models and therefore, predictions of El Niño impacts.

Strategic reserves in Oregon’s forests to prevent biodiversity losses, protect water, and mitigate climate change

Research provides fine scale maps to guide action towards stated goals


Peer-Reviewed Publication

CONSERVATION BIOLOGY INSTITUTE

Contacts: Dr. Beverly Law, bev.law@oregonstate.edu, Ralph Bloemers, ralph@greenoregon.org

(Corvallis, Oregon) Without substantial and sustained reductions in global greenhouse gas emissions and removal of carbon dioxide from the atmosphere by forests and oceans (natural climate solutions), the nation is put at significant risk of abrupt and severe biodiversity losses and transformative impacts to natural systems. According to the Intergovernmental Panel on Climate Change (IPCC), the next 10 to 30 years are a critical window for climate action, when severe ecological disruption is expected to accelerate.


A new paper in the scientific journal Frontiers in Forests and Global Change identifies which forests in Oregon are poised to provide significant benefits to the nation as strategic forest reserves that help prevent biodiversity loss, mitigate climate change, and protect drinking water. Oregon has forests that are among the highest carbon density forests in the world and protecting mature and older forests found here can increase carbon storage and accumulation while protecting wildlife and clean water.


In the eleven western United States, Oregon has the most total forest area and carbon in live tree biomass but the lowest proportion (10%) that is protected at the highest levels, as wilderness areas or strict nature reserves. The study shows that the Coast Range ecoregion has the lowest percentage of its forest lands protected compared to other ecoregions.


The team of experts led by Dr. Beverly Law at Oregon State University developed a framework for identifying the highest priority areas for protection in Oregon and produced detailed maps that can guide immediate action on biodiversity conservation and climate change mitigation. The framework uses fine resolution spatial data to map high priority forestlands, including a new forest carbon map (30 m resolution). Compared with prior work, this new scientific research provides a finer scale analysis and includes a resilience metric that represents landscape connectivity and topography for wildlife movement and habitat suitability, and identifies areas within each ecoregion that are ranked high priority for carbon density, biodiversity and surface drinking water. Using an ecoregion-based conservation approach ensures there is enough un-fragmented habitat to maintain viable populations of native wildlife.


National and international targets identify how much needs to be protected. Many countries have already pledged to protect 30% of their land and water areas by 2030 for biodiversity conservation, carbon and water. Protecting 50% of land and water by 2050 is widely viewed as critical to protecting global biodiversity.


The authors found that Oregon’s surface drinking water sources and forest habitat for birds, mammals, amphibians and reptiles could increase to 50 to 70% protection at the highest levels by 2050. Protected aboveground biomass carbon could increase to 4 to 6 times current protected areas by 2050. Most of high preservation priority areas are on federal lands (67%) followed by private lands (28%). Public lands can more readily ensure permanence of protection through time. Doing so would provide clean drinking water and habitat for wildlife.

Sr-Nd isotope baseline in Silk Road regions enables archaeological provenance

Peer-Reviewed Publication

UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA

Silk Road 

IMAGE: SILK ROAD (IMAGE FROM UNSPLASH.COM) view more 

CREDIT: /

Recently, Associate Professor LV Qinqin from the University of Science and Technology of China (USTC) of the Chinese Academy of Sciences (CAS), constructed the first largescale, semi-quantitative Sr-Nd isotope baseline for the vast Silk Road regions, and validated its application in plant-ash glass provenance. The study was published in Journal of Archaeological Science.  

Archaeologists frequently utilize radiogenic Sr and Nd as isotopic tools where the baseline determination is in indispensable need. In many Silk Road regions, the construction of Sr-Nd baseline is blocked by severe deficiency of available data.

LV and collaborators investigated the bioavailable Sr and detrital Nd signatures along the Silk Road. They divided these regions into several major isotopic zones and proposed the likely isotopic compositional ranges of each zone, which eventually constituted the general Sr-Nd isotope baseline framework. 

To validate the benefits of the Sr-Nd isotope baseline, researchers applied it into two provenance cases of plant-ash glass. Using the integrative Sr-Nd isotope approach, they discovered that northern Mesopotamia supplied raw materials for glass-making for a long period. In addition, they found that plant-ash glass has multiple origins including Central Asia and Mesopotamia. The two cases further confirmed the huge potential of Sr-Nd analyses in archaeology. 

This progress supplements the lack of reference isotope baseline, and provides guidance for the future refinement. This study reveals the circulation pattern of Islamic plant-ash glass and its raw material sources, thus contributing to the research on cultural communications through ancient glass and ceramics in Silk Road regions.

Dinosaur teeth reveal what they didn’t eat

New analysis of T. rex and other dinosaur teeth gives insight into their eating habits

Peer-Reviewed Publication

UNIVERSITY OF TOKYO

Run for it. 

IMAGE: THIS LYTHRONAX LIVED IN NORTH AMERICA IN THE LATE CRETACEOUS PERIOD. THESE TYRANNOSAURIDS ARE ESTIMATED TO HAVE WEIGHED UP TO 2.5 TONS. view more 

CREDIT: 2022 D.E. WINKLER

Scratches on dinosaur teeth could reveal what they really ate. For the first time, dental microwear texture analysis (DMTA) has been used to infer the feeding habits of large theropods, including Allosaurus and T. rex. By taking 3D images of individual teeth and analyzing the pattern of marks scratched into them, researchers could reason which dinosaurs may have frequently crunched on hard bone and which may have regularly eaten softer foods and prey. This technique opens up a new avenue of research for paleontology, helping us to better understand not only dinosaurs themselves but also the environment and communities in which they lived.

From Fantasia to Jurassic Park, the T. rex is seen as a terrifying apex predator that would chase down its prey and crunch on it whole. But how much did this iconic dinosaur actually chow down on bones? And what about other predatory dinosaurs that existed long before it?

Researchers from the University of Tokyo, in collaboration with teams from the University of Mainz and the University of Hamburg in Germany, have used dental microwear texture analysis (DMTA), a scanning technique to examine topographical dental wear and tear in microscopic detail, on individual dinosaur teeth from more than 100 million years ago to better understand what they may have eaten. “We wanted to test if we could use DMTA to find evidence of different feeding behaviors in tyrannosaurids (from the Cretaceous period, 145 million to 66 million years ago) compared to the older Allosaurus (from the Jurassic period, 201 million to 145 million years ago), which are both types of theropods,” explained postdoctoral fellow Daniela Winkler from the Graduate School of Frontier Sciences. “From other research, we already knew that tyrannosaurids can crack and feed on bones (from studies of their feces and bite marks on bone). But allosaurs are much older and there is not so much information about them.”

DMTA has mainly been used to study mammal teeth, so this is the first time it was used to study theropods. The same research team from the University of Tokyo also recently pioneered a study on DMTA in Japanese sauropod dinosaurs, famous for their long necks and tails. A high-resolution 3D image was taken of the tooth surface at a very small scale of 100 micrometers (one-tenth of a millimeter) by 100 micrometers in size. Up to 50 sets of surface texture parameters were then used to analyze the image, for example, the roughness, depth and complexity of wear marks. If the complexity was high, i.e., there were different-sized marks which overlaid each other, this was associated with hard object feeding, such as on bone. However, if the complexity was low, i.e., the marks were more arranged, of a similar size and not overlapping, this was associated with soft object feeding, like meat.

In total, the team studied 48 teeth, 34 from theropod dinosaurs and 14 from crocodilians (modern crocodiles and alligators), which were used as a comparison. The team was able to study original fossilized teeth and take high-resolution silicon molds, thanks to loans provided by natural history museums in Canada, the U.S., Argentina and Europe. “We actually started dental microwear research of dinosaurs in 2010,” said Lecturer Mugino Kubo from the Graduate School of Frontier Sciences. “My husband, Dr. Tai Kubo, and I had started collecting dental molds of dinosaurs and their contemporaries in North and South Americas, Europe, and of course Asia. Since Daniela joined my lab, we utilized these molds to make a broader comparison among carnivorous dinosaurs.”

“It was especially challenging to carry out this research during the pandemic,” said Winkler “as we rely on being able to gather samples from international institutions. The sample size might not be so large this time, but it is a starting point.”

Winkler says what they found surprising was that they didn’t find evidence of much bone crushing behavior in either Allosaurus or tyrannosaurids, even though they know that tyrannosaurids ate bone. There may be several reasons for this unexpected outcome. It could be that although Tyrannosaurus was able to eat bone, it was less commonly done than previously thought. Also, the team had to use well-preserved teeth, so it might be that extremely damaged teeth that were excluded from this study were in such a condition because those animals fed more on bone.

Something the team did find with both the dinosaurs and crocodilians was a noticeable difference between juveniles and adults. “We studied two juvenile dinosaur specimens (one Allosaurus and one tyrannosaurid) and what we found was a very different feeding niche and behavior for both compared to the adults. We found that there was more wear to juvenile teeth, which might mean that they had to more frequently feed on carcasses because they were eating leftovers,” explained Winkler. “We were also able to detect different feeding behavior in juvenile crocodilians; however, this time it was the opposite. Juvenile crocodilians had less wear on their teeth from eating softer foods, perhaps like insects, while adults had more dental wear from eating harder foods, like larger vertebrates.”

Winkler says that the next step with dinosaurs will probably be to look in more detail at the long-necked sauropods, which the team has also been studying. But for now, she is experimenting with something much, much smaller: crickets. The insects’ mouths may be tiny and don’t have any teeth, but the researchers want to see if they can still find evidence of mouth wear using the same technique. “From what we learn using DMTA, we can possibly reconstruct extinct animals’ diets, and from this make inferences about extinct ecosystems, paleoecology and paleoclimate, and how it differs from today.” said Winkler. “But this research is also about curiosity. We want to form a clearer image of what dinosaurs were really like and how they lived all those millions of years ago.”

###

Paper Title: 

Daniela E. Winkler, Tai Kubo, Mugino O. Kubo, Thomas M. Kaiser, Thomas Tütken. First application of dental microwear texture analysis to infer theropod feeding ecology.  Palaeontology, 2022, e12632. doi:10.1111/pala.12632

Funding: 

This work was supported by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (ERC CoG grant agreement no. 681450) to T.T. The Japan Society for the Promotion of Science under a Postdoctoral fellowship awarded to D.E.W. (KAKENHI Grant No. 20F20325).

Useful Links:

Graduate School of Frontier Sciences: https://www.k.u-tokyo.ac.jp/en/index.html

Mugino Kubo Lab: https://sites.google.com/edu.k.u-tokyo.ac.jp/mugino-kubo-lab/home

About the University of Tokyo
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Blue silicon was carefully excreted from a tube onto the teeth and left to dry for a few minutes to create near-perfect replicas, which were removed and taken from the museum in the U.S. city of Salt Lake City, Utah, to Japan for further study.

  


A 100 micrometer-by-100 micrometer (μm) image of the tip of this tooth shows the tiny scratches which were analyzed for complexity and depth of wear features.

CREDIT

2022 Winkler et al.