Category: 7. Science

A collection of dinosaur teeth hailing back to the Cretaceous and Jurassic periods has given scientists a new window into the world’s prehistoric climate.

By studying an isotope of oxygen in the fossils to infer atmospheric carbon dioxide levels, a team led by geochemist Dingsu Feng of the Georg August University of Göttingen in Germany has reconstructed the very air the dinosaurs breathed.

The results show that dinosaur teeth are a powerful tool for scientists, not just for understanding the world in which the dinosaurs lived, but the events that took place, since changing isotope levels can imply events such as massive volcanic eruptions.

Related: The Rise of The Dinosaurs Can Be Tracked in Their Fossilized Poop

“Our findings provide a new research avenue to reconstruct a direct link between land-living vertebrates and the atmosphere they breathed,” paleontologist and geochemist Thomas Tütken of the Institute of Geosciences at Johannes Gutenberg Universität, Mainz in Germany told ScienceAlert.

“Even after up to 150 million years, isotopic traces of the oxygen molecules of the Mesozoic atmosphere that the dinosaur inhaled are still preserved in fossil tooth enamel and can tell us something about the ancient atmosphere composition and global photosynthetic biomass production.”

You don’t just exist in this beautiful world of ours. It also exists in you. Everything you take in – from the food you eat, to the liquid you drink, to even the very air that you breathe – leaves a chemical imprint on your body, including your bones and teeth.

This is true for all vertebrates, including the dinosaurs. Ratios of atoms of the same elements but different masses, known as isotopes, can hint at a variety of ecological and climatic variations that dominate in an organism’s lifetime.

Oxygen atoms attached to carbon dioxide is just one such isotope. In particular, Feng and her team looked for tracers of an isotope called oxygen-17. Processes in the atmosphere result in a lower amount of this particular isotope in the dioxide oxygen gas that is then inhaled by living organisms.

“Air-breathing vertebrates incorporate a fraction of this anomalous air oxygen into their body water pool due to oxidative metabolism of food,” Tütken explained.

“A fraction of this oxygen isotope anomaly is incorporated during biomineralization processes into dental enamel, and survives over millions of years in this vertebrate high tissue and can thus be used to infer past atmospheric CO₂ levels.”

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The researchers recently demonstrated that oxygen isotope ratios in the tooth enamel of living, modern animals provide an accurate representation of atmospheric CO₂ levels. The next logical step was then to see if they could do the same thing with fossils that are millions of years old.

“Dinosaur tooth samples were prime targets to be analyzed as large triple oxygen isotope anomalies were to be expected and could quite precisely be measured,” Tütken said.

Using enamel powders previously taken from specimens obtained from museum collections across Europe for other diet-related reconstructions, Tütken and his colleagues concluded concentrations of CO₂ had been high during the Mesozoic; a finding in agreement with previous investigations into Earth’s CO₂ history.

In the late Jurassic, CO₂ levels were at about 1,200 parts per million, for example; in the late Cretaceous, around 750 parts per million. By comparison, Earth’s atmosphere currently has around 430 parts per million CO₂, and counting.

During the Mesozoic, atmospheric CO₂ was probably produced by much higher levels of volcanic activity than we see today. Two teeth, in particular, seemed to suggest a spike in volcanic activity.

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“There were surprising high triple oxygen isotope anomalies found for one T. rex and one sauropod (Kaatedocus) tooth analyzed compared to the other near-contemporaneous dinosaurs,” Tütken said.

“These potentially reflect atmospheric spikes of high CO₂ levels during the time these individual dinosaurs were alive. Most likely related to volcanic CO₂ emission during large flood basalt eruption events. Thus our study provides new insights into the composition of the Mesozoic atmosphere in which the dinosaurs breathed and indicates that CO₂ levels fluctuated (up to 160 percent) over geologically short time scales.”

Now that the team has shown their technique works, they plan to look at teeth from an event known as the Great Dying, the Permian-Triassic global extinction that took place 252 million years ago and wiped out the vast majority of all animals on Earth. This event has been linked to a devastating period of volcanic activity that wrapped our planet in a volcanic shroud for millions of years.

By reconstructing the atmospheric CO₂ from this period, the researchers hope to learn more about how the Great Dying impacted life on Earth.

The research has been published in the Proceedings of the National Academy of Sciences.

Systematic research fraud has outpaced corrective measures and will only keep accelerating, according to a study of problematic publishing practices and the networks that fuel them. 

The study, published August 4 in Proceedings of the National Academy of Sciences, examined research fraud carried out by paper mills, brokers and predatory publishers. By producing low quality or fabricated research, selling authorship and publishing without adequate quality control and peer review, respectively, these three groups were well known to produce a large volume of fraudulent research. 

“This is a great paper showing how much fraud there is in the scientific literature. The paper also looks at different methods on how to detect problematic papers, networks and editors,” Anna Abalkina, a researcher at Freie Universität Berlin and creator of the Retraction Watch Hijacked Journal Checker, said. 

Researchers and journalists have been looking into paper mills for more than a decade, as they have affected multiple publishers over the years, even before the high-profile retractions of thousands of articles from Hindawi journals.  

The latest study confirms the large volume of suspected paper mill products have been doubling more than twice as fast as corrective measures — both official measures like retractions and unofficial channels like the number of crowdsourced comments flagging problematic papers on PubPeer. 

“It’s like emptying an overflowing bathtub with a spoon,” coauthor Luis Amaral, a professor at Northwestern University, told us. 

To combat this systemic fraud, the researchers call for a global change in research incentives.

Case studies

To look at cases of paper mill activity to inform their larger network design, Amaral and a research team of metascientists examined metadata from the journal PLOS One, and DOIs from IEEE conference proceedings, along with the Retraction Watch Database and PubPeer comments to compile networks of editors who were significantly more likely to accept articles that eventually got retracted or flagged for concern. (Disclosure: Our Ivan Oransky is a volunteer member of the PubPeer Foundation’s board of directors.)

PLOS One has been a known target of paper mill activity in the past. Amaral and colleagues identified networks of editors who accepted an abnormally high rate of papers that were later retracted. The 45 editors implicated in this network edited 1.3 percent of all articles, but 30.2 percent of all retracted articles. More than half of the editors also authored articles that were later retracted. 

Renee Hoch, head of publication ethics at PLOS, told us that since the increased paper mill activity was detected four to five years ago, the company has implemented measures to investigate existing articles and paper mill networks, and thoroughly screen new papers, authors and editors before publication. Even before then, the publisher had expanded its publication ethics team to investigate papers. 

“PLOS was used as a data source in this study in part because PLOS publishes all of our articles Open Access, we list the names of handling editors on our articles, and we allow bulk access to our article content and metadata,” Hoch said. “However, the issues that surfaced in this article are not specific to PLOS One and instead are affecting journals and publishers across the industry.” 

The researchers conducted the same analysis on papers from Institute of Electrical and Electronics Engineers (IEEE) conference proceedings, which have long been a known target for paper mill activity. They found hundreds of conferences produced abnormally high proportions of papers that were later retracted, flagged on PubPeer, or flagged for using tortured phrases. Seven of these conference series were flagged every year the conference was held.

“We believe our preventive measures and efforts identify almost all papers submitted to us that do not meet our standards,” an IEEE corporate spokesperson told us. “To adhere to our standards, IEEE continuously inspects our digital library and acts accordingly when we become aware of possible issues with content, takes the appropriate level of care and time in our review, and, if necessary, retracts nonconforming publications.“ 

In addition to looking at individual journals and publishers, Amaral and colleagues used large databases such as Scopus and Clarivate’s Web of Science, along with PubPeer comments about suspected image duplication to map a network of papers across many large publishers like Springer Nature, Spandidos, Wiley and Elsevier. They found multiple clusters of duplicated images that seemed to be published close in time. Of papers with suspected image duplication, 34.1 percent have been retracted.

The authors’ approach of looking at image duplication networks is innovative and had not been done before, Abalkina said. “It is fascinating to see how paper mills expand like [an] octopus engaging more and more scholars in the network.”

Amaral and colleagues also analyzed the impact of fraud on certain subfields, focusing on RNA biology, which study coauthor Jennifer Byrne of the University of Sydney and others have closely examined for years. The researchers found compromised subfields had a retraction rate around 4 percent, while uncompromised ones remained lower, at about 0.1 percent. 

And the researchers quantified journal hopping using a known paper mill broker, the Academic Research and Development Association (ARDA), which some of the study coauthors described in detail last year for Retraction Watch. ARDA’s website listed journals in which the organization guaranteed publication. As the listed journals were de-indexed from Scopus (at a much higher rate than other journals – 33.3 percent versus 0.5 percent), new journals would be added to the list. 

Despite publishers’ current efforts, the researchers calculated that only 28.7 percent of suspected paper mill products have been retracted. The figure came from the researchers’ dataset of paper mill products and the Retraction Watch Database, using data through 2020, although data show paper mill growth since then has been rapid. They extrapolated from current trends that “only around 25 percent of suspected paper mill products will ever be retracted and that only around 10 percent of suspected paper mill products will ever reside in a de-indexed journal.”

These numbers likely underestimate the full extent of the problem, because they “rely on the instances of scientific fraud that have been reported,” they wrote in the paper.

What can be done?

Amaral compared the scale of the issue to combating the ozone hole over Antarctica, and said that the scale of the solutions need to match. “We need the biggest, most important stakeholders of science to come together to talk about what needs to be done, what standards need to be implemented and not wait for the problem to solve itself,” he told us. He named national organizations like the U.S. National Academies, the Chinese Academies of Sciences, and the U.K. Royal Society as stakeholders big enough to influence large organizations like publishers to act. 

“They need to implement decisions, and they need to advocate strongly for those decisions to be adopted by journals, by funding agencies, by employers, universities, the national labs,” Amaral told us. “It’s not going to be an individual choice.”

However, individuals can play a role in advocating for change. Anyone can “press on policymakers to end the culture of hyper-competition in science,” Reese Richardson, a coauthor of the study and a postdoctoral researcher at Northwestern University, told us. “Scientists are all competing against each other for an increasingly scarce pool of resources,” he said. 

Scientists can help address the problem in additional ways, Richardson told us. “What scientists can do in their own personal capacity is do post-publication peer review, and take a critical eye to the literature in their fields because it’s clear that we’re only detecting a tiny, tiny fraction of the problem,” he said. 

He also suggested researchers develop “high throughput approaches to identify problematic articles” and metascientists “can use rare signals, like the comments that people leave on PubPeer observations about image misidentification and image duplication and instrument misidentification, tortured phrases … to understand what’s happening behind the scenes. That’s the job of meta scientists – to use public visible indicators to get at what’s invisible.”

We’ve covered a number of these high throughput approaches in the past, including one Richardson and Amaral developed with others to detect papers that misidentify microscopes used in their studies.

“We are part of a community that has been fighting for recognition of something that has been concerning us,” Amaral told us. “We are grateful for everything that everyone else has done, and to be a part of that, because science is very important to us and we want to do things to maintain the ideals of what science should be.”

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August 4, 2025, Mountain View, CA – The SETI Institute awarded a new education grant through its Support Technology, Innovation, Development and Education (STRIDE) program. Space Science for Youth in South Africa is a professional development program for Girl Guides South Africa (GGSA) staff and volunteers and is additionally funded by The Center for Radio Astronomy and Technologies, Rhodes University. The project will leverage the SETI Institute’s experience developed through Reaching for the Stars: NASA Science for Girl Scouts which developed space science badges for Girl Scouts aged 5-18 and provided training for Girl Scout volunteers and organizers. SETI Institute Director of Education Pamela Harman will lead Space Science for Girls in South Africa as PI, with Jessica Henricks as Co-I.

“This STRIDE award leverages our expertise to bring space science activities and career awareness to GGSA,” said Harman.  GGSA aims to empower girls and women to reach their full potential and gives girls the confidence, skills and aspirations to advocate for change and make an impact in the world.”  

Developed and delivered by the SETI Institute, this 2.5 day in-person training in July 2025 will equip a carefully selected group of GGSA leaders with knowledge, tools, experience, and resources to expand engaging and inclusive space science education for girls ages 4.5 – 18. The leaders will not only be prepared to deliver space science programs directly, but, more importantly, to train the GGSA’s adult volunteer leaders who serve GGSA’s 20,000 members in urban and rural areas.  

“By sharing a thoughtfully curated set of inquiry-based space science activities with experienced Girl Guide volunteer leaders, this project maximizes its impact through strategic capacity-building,” said Henricks. “It’s inspiring to see how this train-the-trainer program will empower GGSA leaders across South Africa to deliver fun and inclusive after-school STEM learning experiences.”

The training will feature hands-on experience and research-backed activities from the Girl Scouts of the USA (GSUSA) Space Science badges, best practices in inclusive facilitation, an overview to astronomy and space science careers, and possible program pathways appropriate for age and setting. Role models and amateur astronomers will be invited to participate, sharing their inspiring experiences. The components combine to form an innovative, high impact, stand-alone education and outreach program that can be and disseminated.

“We are delighted to be able to contribute to this initiative, especially in a year when Eugenia Mbekeni, a leading figure of GGSA, has just been awarded an honorary doctorate by the University,” said Oleg Smirnov, SKA Research Chair for Radio Astronomy Techniques and Technologies, Rhodes University. “South Africa’s success story in radio astronomy should be a source of national pride, and inspiration for more young women to get into STEM fields. Partnering with GGSA is a perfect way to get this message across.”

“This partnership builds on Girl Guides South Africa’s existing programme through imparting best practices in inclusive facilitation for adult leaders, an overview to astronomy and space science careers for the girls, and possible programme pathways in an age-appropriate manner and setting,” said Lindelwa Ximiya, Chief Commissioner of Girl Guides South Africa. “In line with our learning and reward methodology, the girls will be excited to receive their Space Science badges on completion of the challenges.”

STRIDE fund for SETI Institute researchers and EOC (Education, Outreach, and Communications) professionals to develop innovative research and education proposals. In July 2024, the SETI Institute announced the first STRIDE science grants.

STRIDE grants include funding for basic research, technology development, prototyping, equipment and instrumentation, field expedition work, education program development, materials, hardware, software, and more. Last year, the SETI Institute announced a philanthropic gift of $200M from the estate of Franklin Antonio, a visionary supporter and catalyst of the work of the SETI Institute for more than 12 years. Co-founder of communications chip company Qualcomm, Antonio left an extraordinary legacy to enable breakthrough science in the search for intelligent life beyond our world. The Franklin Antonio Bequest funds the STRIDE program, and the SETI Institute expects to solicit it annually.

More information about the SETI Institute’s STRIDE program is here.

About the SETI Institute
Founded in 1984, the SETI Institute is a non-profit, multi-disciplinary research and education organization whose mission is to lead humanity’s quest to understand the origins and prevalence of life and intelligence in the universe and to share that knowledge with the world. Our research encompasses the physical and biological sciences and leverages expertise in data analytics, machine learning and advanced signal detection technologies. The SETI Institute is a distinguished research partner for industry, academia and government agencies, including NASA and NSF.

Contact information
Rebecca McDonald
Director of Communications
SETI Institute
rmcdonald@seti.org

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NASA’s Europa Clipper spacecraft successfully tested its ice-penetrating radar system during a close flyby of Mars earlier this year, proving that the probe is ready for its main mission: peering beneath the frozen crust of Jupiter’s moon Europa to search for signs of subsurface liquid water and possibly even determine if those oceans have the ingredients to form and sustain life.

Launched in October 2024, Europa Clipper is on a 1.8-billion-mile (2.9-billion-kilometer) journey to study Jupiter and its moons. On March 1, it flew within 550 miles (884 kilometers) of Mars’ surface in a planned gravity assist maneuver to fine-tune its trajectory.

The Burgess Shale in British Columbia is renowned for its exceptional preservation of soft tissues in fossils, including limbs and guts. While trilobites are abundant in the fossil record thanks to their hard exoskeleton, their soft limbs are rarely preserved and poorly understood. However, Olenoides serratus, a particularly abundant and well-preserved Burgess Shale trilobite, offers a unique opportunity to study these appendages.

In a new study published in the BMC Biology , researchers led by Sarah Losso, postdoctoral fellow in the Department of Organismic and Evolutionary Biology (OEB) at Harvard, analyzed 156 limbs from 28 O. serratus fossil specimens to reconstruct the precise movement and function of these ancient arthropod appendages—shedding light on one of the planet’s earliest and most successful animals.

“Understanding behavior and movement of fossils is challenging, because you cannot observe this activity like in living animals,” said Losso. “Instead, we had to rely on carefully examining the morphology in as many specimens as possible, as well as using modern analogues to understand how these ancient animals lived.”

Arthropods have jointed legs composed of multiple segments that can reach upwards (extend) or downwards (flex). The range of motion depends on the difference between how far each joint can reach in either direction. This range, along with the leg and shape of each segment, determines how the animal uses the limb for walking, grabbing, and burrowing.

Horseshoe crabs, common arthropods found along the eastern shore of North America, are frequently compared to trilobites even though they are not closely related. Horseshoe crabs belong to a different branch of the arthropod tree, more closely related to spiders and scorpions, whereas trilobites’ family ties remain uncertain. The comparison is due to the similarity in that both animals patrol the ocean floor on jointed legs. The results, however, showed less similarity between the two animals.

Unlike horseshoe crabs, whose limb joints alternate in their specialization for flexing and extending—a pattern that facilitates both feeding and protection—O. serratus displayed a simpler, but highly functional limb design.

“We found that the limbs of O. serratus had a smaller range of extension and only in the part of the limb farther from the body,” explained Losso. Although their limbs were not used in exactly the same way as horseshoe crabs, Olenoides could walk, burrow, bring food towards its mouth, and even raise its body above the seafloor.

To bring their findings to life, the team created sophisticated 3D digital models based on hundreds of fossil images preserved at different angles. Because fossilized trilobite limbs are usually squashed flat, reconstructing them in three-dimensions posed a challenge.

“We relied on exceptionally well-preserved specimens, comparing limb preservation across many angles and filling in missing details using related fossils,” said senior author Professor Javier Ortega-Hernández, also in OEB.

The team compared the shape of trace fossils with the movement of the limbs. “Olenoides serratus could create trace fossils of different depths using different movements,” Losso explained. “They could raise their body above the sediment in order to walk over obstacles or to move more efficiently in fast-flowing water.”

Surprisingly, the researchers discovered that the male species also had specialized appendages used for mating, and that each leg also had a gill used for breathing.

While more than 22,000 species of trilobites have been described, less than 0.2% show any trace of legs at all. Nevertheless, lack of preservation does not imply these ancient arthropods went legless—rather, their soft limbs simply seldom survived the fossilization process. The rare conditions of the Burgess Shale—a fast burial by underwater landslides cutting off oxygen—were key to capturing such fleeting biological details.

The study provides a rare window into a more dynamic picture of life more than half a billion years ago, as trilobites like Olenoides serratus scuttled across the seabed with sophisticated limbs that could burrow and foraged through prehistoric seas, revealing not just how they survived, but how they thrived.

NASA’s Curiosity Mars rover used its Mars Hand Lens Imager (MAHLI), a camera on the end of its robotic arm, to view this wind-eroded rock shaped like a piece of coral on July 24, 2025, the 4,608th Martian day, or sol, of the mission. Nicknamed “Paposo” by the rover’s science team, the rock was about 2 inches (5 centimeters) from the MAHLI camera when this was taken.

Figure A is another MAHLI image taken about 10 inches (25 centimeters) away from Paposo.

Curiosity has found many small features like this one, which formed billions of years ago when liquid water still existed on Mars. Water carried dissolved minerals into rock cracks and later dried, leaving the hardened minerals behind. Eons of sandblasting by the wind wore away the surrounding rock, producing unique shapes.

This common process is seen extensively on Earth and has produced fantastic shapes on Mars, as well, including a flower-shaped rock.

Curiosity was built by NASA’s Jet Propulsion Laboratory, which is managed by Caltech in Pasadena. JPL leads the mission on behalf of NASA’s Science Mission Directorate in Washington as part of NASA’s Mars Exploration Program portfolio.

For more about Curiosity, visit:

science.nasa.gov/mission/msl-curiosity