The discovery offers the strongest evidence so far that planets with broadly Earth-like temperatures and rocky compositions may exist beyond our solar system while also retaining conditions that could potentially support life.

“An atmosphere is essential for a planet to support life as we know it,” said lead author Collin Cherubim, who recently earned his Ph.D. in Earth and Planetary Sciences from Harvard University.

“This is the first time anyone has found an atmosphere on a rocky planet in the habitable zone of another star.”

Helium Reveals an Exoplanet Atmosphere

The study, published July 16 in Science, describes observations of helium escaping from LHS 1140 b, a rocky exoplanet located about 48 light-years from Earth. The signal supports earlier theoretical predictions that the planet possesses an atmosphere.

LHS 1140 b circles a red dwarf star within its habitable zone. This is the region around a star where temperatures and other environmental conditions may allow liquid water to remain on a planet’s surface.

Scientists have identified thousands of exoplanets, including several rocky worlds in habitable zones. However, confirming whether those planets have atmospheres has been one of the most difficult challenges in exoplanet research.

“Twenty years ago we wondered whether other terrestrial-type planets even existed,” said Robin Wordsworth, Gordon McKay Professor of Environmental Science and Engineering and Professor of Earth and Planetary Sciences at Harvard and one of Cherubim’s dissertation advisors. “Then we learned they’re common, and found some in the habitable zone. The next question was whether any of them had managed to keep an atmosphere. Now we know at least one has.”

A Rocky World That Kept Its Atmosphere

Previous research has identified rocky planets orbiting within the habitable zones of their stars. This study, however, is the first to clearly show that one of those worlds has an atmosphere that may have endured for billions of years.

Cherubim and his colleagues developed a theoretical model predicting that the upper atmosphere of LHS 1140 b would contain large amounts of helium slowly escaping into space.

The researchers tested that prediction using the Warm Infrared Echelle (WINERED) Spectrograph at the Magellan Observatory in Chile. Their observations took advantage of an unusual event in which LHS 1140 b and another planet crossed in front of their star during the same night.

The second planet showed no sign of an atmosphere. LHS 1140 b, however, produced a clear signal of helium escaping from the planet, providing evidence that it still retains an atmosphere.

A Prediction Confirmed by Telescope Data

Cherubim’s joint advisor David Charbonneau, head of the Harvard Department of Astronomy and astronomer in the Center for Astrophysics | Harvard & Smithsonian, initially doubted whether the plan would succeed. The prediction came from a mathematical model, and this type of signal had never before been observed from a rocky world.

The results changed his mind.

“Collin analyzed the planets we knew about and predicted that this one would have a helium atmosphere,” Charbonneau said. “Then he organized telescope time, got the data, and the detection was statistically rock solid.”

The discovery indicates that astronomers may be able to study the atmospheres of rocky exoplanets from the ground by looking for gases escaping into space.

A Promising Target in the Search for Life

Astronomers estimate that the atmosphere of LHS 1140 b has survived for more than three billion years. That longevity makes the planet an especially promising target for additional observations.

Cherubim hopes to identify the atmosphere’s complete chemical composition and eventually determine whether the planet has surface oceans or other features connected with habitability. He and his colleagues also plan to use the model to search for additional rocky worlds with atmospheres.

“This has been a model validation, and hopefully it’s just the first of many more observations to come,” he said.

The project was led by Prof. Qiaomei Fu of the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) at the Chinese Academy of Sciences. Researchers from the Shaanxi Provincial Academy of Archaeology and several other institutions also contributed to the work.

Over 13 years, the team conducted large-scale, high-resolution analyses of nuclear DNA from 169 ancient human samples (144 unrelated individuals). The remains came from Shimao, nearby archaeological sites, and locations in the southern Shanxi region.

A Vast Walled Settlement in Ancient China

Shimao dates to approximately 4200-3700 years before the present and is located in northern Shaanxi Province, China. Covering about four square kilometers, the enormous stone-walled settlement was divided into separate functional areas.

Archaeological evidence indicates that Shimao had a strongly stratified society with organized political and social systems. The site has also produced extensive evidence of ritual activity and human sacrifice.

Local Roots and Distant Connections

Researchers compared the newly obtained genomes with previously published ancient DNA from populations across China. Their results indicate that most of Shimao’s inhabitants descended from local people who had lived in the region about 1,000 years earlier.

The analysis also uncovered both genetic and cultural links to Yangshao Culture, a major Neolithic civilization that developed across the Loess Plateau near the Yellow River. These connections provide important clues about where the Shimao population came from and how its society developed.

The Shimao people were also closely connected to communities associated with Taosi Culture (southern Shanxi), steppe Yumin-related groups, and southern rice-farming populations. These relationships point to extensive contact and exchange among prehistoric farming and pastoral communities across a wide geographic area.

Ancient DNA Reconstructs Shimao Families

Around 80 human skulls have been discovered near Shimao’s East Gate. Before the late Shang period, no other archaeological site in China had produced such a large collection of human skulls.

Genetic analysis allowed the researchers to reconstruct family pedigrees covering as many as four generations. The results suggest that Shimao’s social hierarchy was organized through patrilineal descent, meaning ancestry and status were traced through fathers. The population also followed patrilocal residence, in which women typically moved to live with or near the families of their male partners.

Together, these patterns offer a rare view of how family relationships may have shaped authority, inheritance, and social rank within the settlement.

Male Sacrifice at Shimao’s East Gate

The findings also overturn a long-held idea about the people sacrificed near Shimao’s East Gate. Earlier interpretations suggested that most of the victims were female, but the genetic evidence shows that nine out of ten burials examined there were male.

A clear pattern emerged across different areas of the settlement. Male sacrificial victims were concentrated near the East Gate, while female sacrificial remains were found in elite cemeteries including Huangchengtai and Hanjiagedan.

This separation suggests that sacrifice at Shimao was carefully organized. Men and women may have been selected for different ceremonies, with their roles determined by the purpose of the ritual and the location where it took place.

New Clues to the Rise of Early States

The genetic evidence indicates that Shimao’s population primarily developed from local groups with Yangshao cultural ancestry in northern Shaanxi. This establishes at least 1,000 years of cultural and genetic continuity in the region.

At the same time, the population’s links to distant communities show that Shimao was not isolated. Its people participated in broad networks connecting agricultural and pastoral societies across northern, central, and southern China.

The study also provides the first direct genetic evidence that can be used to investigate how power was inherited at Shimao, who belonged to its ruling families, and how different social classes were formed. These insights may help researchers better understand the family systems and political structures that contributed to the emergence of early states in East Asia.

Much of what researchers know about pygmy sperm whales has come from animals that wash ashore. Strandings are especially common along the southeastern United States, where this species appears more frequently than almost any other large marine mammal.

Whale Strandings Reveal Hidden Health Problems

Examinations of stranded whales have uncovered several recurring medical problems, including stomach ulcers. These ulcers are sometimes associated with Helicobacter, a group of bacteria that can live in the stomach and intestines of many animals, including humans and whales.

After reviewing more than 20 years of stranding records and preserved tissue samples, researchers at Florida Atlantic University’s Harbor Branch Oceanographic Institute and collaborating institutions identified three Helicobacter genotypes that had never been documented before.

The study, published in the Journal of Wildlife Diseases, marks the first confirmed discovery of these bacterial genotypes in pygmy sperm whales. The researchers named them Kogia Helicobacter 1, 2 and 3. Beyond offering new insight into an elusive whale species, the findings raise broader questions about how bacterial infections may affect marine wildlife and ocean health.

“Helicobacter bacteria have long been associated with gastrointestinal disorders in humans and other animals, including chronic gastritis, ulcers, and even gastric cancer,” said Annie Page, D.V.M., Ph.D., senior author, an associate research professor and clinical veterinarian at FAU Harbor Branch. “To find novel strains of these bacteria in a deep-diving whale species is intriguing.”

Three Bacterial Genotypes New to Science

From 1999 through 2020, FAU Harbor Branch responded to 59 pygmy sperm whale strandings. Post-mortem examinations were completed on 80% of those animals.

In four cases, scientists found spiral-shaped, “spirilliform” bacteria within stomach tissue. The team later reexamined the preserved samples using histopathology, molecular testing and DNA sequencing. That analysis revealed several previously unknown Helicobacter genotypes.

“Two of the genotypes, Kogia Helicobacter 1 and 2, are genetically similar to known Helicobacter species previously found in other cetaceans — such as dolphins and porpoises — and in humans,” said Wendy Marks, corresponding author and a research coordinator of the marine wildlife veterinary medicine and research lab at FAU Harbor Branch. “But Kogia Helicobacter 3 belongs to a more divergent lineage, which emphasizes the possibility that there are far more undiscovered bacteria in the ocean than we realize.”

Researchers found both Kogia Helicobacter 1 and 3 in the forestomach tissue of one whale.

Infected Whales Showed Stomach Damage

Each of the four whales that tested positive also showed clear signs of gastrointestinal disease.

“All four whales that tested positive for Helicobacter had visible gastric pathology,” said Page. “We saw signs of gastritis, gastric ulcers, fibrosis and nematode infestations. In one case, there was also colitis, which suggests that the infection may not be limited to the stomach. While Helicobacter wasn’t listed as the cause of death in any of the whales, these lesions raise questions about its role in gastrointestinal disease.”

The researchers did not conclude that Helicobacter directly caused the whales’ deaths. However, the repeated presence of inflammation, ulcers, tissue scarring and other digestive problems suggests the bacteria could contribute to chronic illness.

Helicobacter was first reported in marine mammals in 2000. Since then, related bacteria have been detected in several cetacean species around the world. In some animals, infection has been connected with low energy, loss of appetite, regurgitation, stomach ulcers and inflammation. Many of these symptoms are similar to those seen in infected humans.

Possible Risks for Vulnerable Whale Populations

“Whales, like humans, appear to be susceptible to certain microbial infections that we’re only beginning to understand,” said Marks. “If chronic Helicobacter infections are causing health issues in these animals, it could have implications not only for individual whale health, but for entire populations — especially for species that are already vulnerable.”

Because pygmy sperm whales are so difficult to study at sea, researchers still do not know how widespread the newly identified bacteria may be or how much they affect the animals over time. Additional testing will be needed to determine whether these infections contribute to illness, strandings or population-level health problems.

The project brought together researchers from FAU Harbor Branch, the University of Florida’s College of Veterinary Medicine, Colorado State University and Marine Mammal Pathology Services.

Decades of Stranding Research Pay Off

“This research underscores the value of long-term marine mammal stranding response programs,” said Page. “Without the ability to study these stranded animals over decades, we never would have discovered these bacteria. Every whale tells a story, and sometimes that story leads us into entirely new scientific territory.”

Study co-authors are Jessy Castellanos-Gell, Ph.D.; Steven Tillis, Ph.D.; James F.X. Wellehan, D.V.M., Ph.D., DACZM; and April Childress, all with the College of Veterinary Medicine, University of Florida; Nicole Pegg, FAU Harbor Branch; David Rotstein, D.V.M., Marine Mammal Pathology Services; Sushan Han, D.V.M., Ph.D., Diagnostic Medicine Center, Colorado State University; and Steve Burton, director, stranding and population assessment, FAU Harbor Branch.

The research was supported by the Florida State Specialty License Plate Program through the “Protect Florida Whales” grant, which is administered by the Harbor Branch Oceanographic Institute Foundation.

About 66 million years ago, two South American sauropods could rise onto their hind legs and remain there for relatively long periods, especially when they were young. This ability may have helped them reach leaves high in trees, appear more intimidating to predators, attract mates, or reproduce.

The dinosaurs, Uberabatitan from Brazil and Neuquensaurus from Argentina, were modest in size compared with the largest sauropods. Even so, they were roughly comparable to modern elephants. Adult Uberabatitans may have grown as long as 26 meters, making them the largest dinosaurs known from Brazil.

New research suggests that their ability to stand upright declined as they grew. Younger animals were better able to support themselves on two legs, while adults probably experienced much greater strain because of their increasing weight.

The findings come from a study supported by FAPESP and published in the journal Palaeontology. The international research team included scientists from Brazil, Germany, and Argentina.

Testing Dinosaur Bones With Engineering Tools

To investigate how sauropods handled the forces involved in standing upright, the researchers turned to a computational method commonly used in engineering.

Their goal was to estimate how much stress gravity and body weight placed on the femur, or thigh bone, when each dinosaur shifted its weight onto its hind legs.

“Smaller sauropods like these had a bone and muscle structure that allowed them to stand more easily and for longer on their two hind legs. Larger ones were probably also able to stand, but for a shorter time and with less comfort, since the position caused a lot of stress on the femur,” summarizes Julian Silva Júnior, a postdoctoral researcher at the School of Engineering of São Paulo State University (FEIS-UNESP) in Ilha Solteira, Brazil.

Silva Júnior is the study’s first author. He carried out the research during an internship at the University of Tübingen in Germany with a scholarship from FAPESP.

The team created digital reconstructions of the femurs of seven sauropod species. The selected dinosaurs represented different evolutionary branches, body sizes, and anatomical features. Their models were built from fossils preserved in natural history museums around the world.

Simulating the Forces of Standing Upright

The scientists used finite element analysis (FEA), a method that breaks a structure into many small sections and calculates how each part responds to pressure, weight, heat, or other forces. Engineers often use the same approach to test whether bridges, buildings, and machines can withstand stress.

“Using this technique, we performed two simulations. One dealt with the extrinsic scenario, simulating the force coming from outside to inside. In this case, gravity and the animal’s own weight on the femur when the dinosaur was standing on its hind legs. In the other, we analyzed the intrinsic scenario, the force that the muscles would exert on the femur,” Silva Júnior explains.

By combining the two simulations, the researchers estimated the total stress experienced by the femur of each species.

The lowest stress levels appeared in the two South American sauropods. One was a juvenile Uberabatitan ribeiroi (named after the Brazilian municipality of Uberaba, where it was found, and coincidentally, Silva Júnior’s hometown). The other was Neuquensaurus australis (found near the Neuquén River in Argentina).

Both lived during the Late Cretaceous period, about 66 million years ago.

Stronger Bones Gave Smaller Sauropods an Edge

The researchers found that the two species had particularly robust femurs. Their thicker, sturdier bones were better able to spread out the forces created when the animals stood upright.

“They had more robust femurs and could dissipate stress better. The bigger ones had very large muscles and even giant femurs, but not enough to support their weight. That doesn’t mean they couldn’t stand up, but they probably chose the best time to do so, because it must have been an uncomfortable position,” says the paleontologist.

Larger sauropods may still have been capable of rising onto their hind legs. However, the simulations suggest that they could not hold the pose as comfortably or for as long.

Adult Uberabatitan individuals probably faced the same problem. Although the juvenile examined in the study was well suited to standing upright, fully grown animals would have carried far more weight. That additional mass likely placed them under levels of stress similar to those experienced by other giant sauropods.

Why Sauropods May Have Stood on Two Legs

Standing upright could have provided several important advantages.

Sauropods were plant eaters, so rising onto their hind legs may have allowed them to reach vegetation high in trees that was unavailable to shorter animals. The posture could also have played a role in reproduction by allowing males to mount females or perform visual displays to attract potential mates.

The pose may also have served as a defensive strategy. By lifting the front of the body into the air, a sauropod would have appeared even larger and more threatening to approaching predators.

When supported by both hind legs and the tail, the animal would have formed a tripodal stance, meaning that three points of contact helped stabilize its body.

Important Limits of the Study

The researchers note that their models did not include every structure that would have affected how the dinosaurs stood.

For example, the simulations did not account for cartilage, the flexible tissue that cushions joints and can help absorb and distribute stress. They also did not model the support provided by the tail while the dinosaur was in a tripodal position.

Because cartilage was not analyzed in any of the seven specimens, the researchers assumed that it played a similar role across the species. This means the method is most useful for comparing the dinosaurs with one another rather than producing an exact measurement for each individual animal.

“The tool we use is very efficient for comparisons, even if the answer isn’t exact for each one. By comparing representatives from different lineages, we can get a fairly accurate picture of how these animals behaved millions of years ago,” says the researcher.