A bird that lived alongside dinosaurs may have preened its feathers like modern birds — despite a full mouth of teeth that also let it chomp like a dino.

A new 3-D reconstruction of the skull of Ichthyornis dispar, which lived during the Late Cretaceous epoch between 87 million and 82 million years ago, reveals that the ancient fowl had a small, primitive beak and a mobile upper jaw. That mobility allowed the bird to use its beak with precision to groom itself and grab objects, similar to how modern birds employ their beaks, researchers report in the May 3 Nature. But I. dispar also retained some features from its nonavian dinosaur ancestors, including strong jaw muscles in addition to the teeth.
“I. dispar holds a special place because it was for the longest time one of the only known toothed birds,” says Lawrence Witmer, a vertebrate paleontologist at Ohio University in Athens, who was not involved in the new study. By providing the first in-depth look at the bird’s skull, the study provides important new details on the transition from the skin-covered, toothy jaws of dinosaurs into the keratin-covered, toothless beaks of modern birds, Witmer says.

Indeed, I. dispar is a paleontology textbook staple. About 150 years ago, paleontologist Othniel C. Marsh described a ternlike water bird that had a wingspan of about 60 centimeters. The fossil revealed that the extinct bird shared some traits with nonavian dinosaurs, such as a full mouth of teeth. However, its wings and breastbone strongly resembled those of modern birds, suggesting the bird could fly.

Unlike the rather reptilian skull of the dino-bird Archaeopteryx (SN: 4/14/18, p. 9), I. dispar’s skull looks much more like that of modern birds, with a beak and relatively large head, says study coauthor Bhart-Anjan Bhullar, a vertebrate paleontologist at Yale University. But details on these structures have been lacking; the skulls of fossils dug up in the 19th century were smashed flat in places, Bhullar says. “A lot of important anatomy is obscured because of that.”

Then, in 2014, researchers unearthed a new I. dispar fossil with a nearly perfectly preserved skull. From that fossil, three other partial skulls from different museum collections, and a reanalysis of the skull discovered 150 years ago, the researchers created a mosaic of the complete ancient bird’s head in 3-D.
The reconstruction revealed that I. dispar had a mobile upper jaw that the bird could raise independently of the lower jaw, as modern birds do. That range of motion allowed the animal to use its tiny beak like tweezers to peck or preen or grasp objects. But the bird also had large holes in the sides of the skull, representing regions where jaw muscles were attached. The size of these holes suggests that I. dispar had strong jaw muscles, which allowed it to chomp with its teeth to hold food, like nonavian dinosaurs did. “It was pecking like a bird and biting down like a dino,” Bhullar says.

By measuring the detailed structures of the braincase, the team also determined that I. dispar’s brain resembled that of modern birds in many ways, including its large forebrain – related to cognitive abilities – and its big optic lobes, which process images sent from the eyes. “This thing was thinking like a bird, and had sensitive vision and motor coordination,” Bhullar adds, suggesting that these adaptations are related to the intense physical requirements for complex flight.

Vertebrate paleontologist Luis Chiappe of the Natural History Museum in Los Angeles commends the careful anatomical study of this important historical fossil. But he is not convinced that the size of the braincase is necessarily related to capability for flight, or that the transitional features observed in this species are representative of the dino-to-bird transition in general. “We have big questions about what was happening with birds in the Late Cretaceous — there is very little known about their skull morphology,” Chiappe says. “It could be that what we see in Ichthyornis might not be representative of an evolutionary trend.”

A geology voyage to study fluid discharge from a rocky outcrop deep below the ocean’s surface turned up something else: A population of brooding purple octopuses. The colony is probably doomed due to the warm, low-oxygen water coming out of the rock, but those ill-fated cephalopods may be an indicator that a healthy population is hiding out nearby, a new study contends.

The octopuses reside on Dorado Outcrop, some 250 kilometers off the coast of Costa Rica and 3,000 meters deep in the sea. The outcrop is essentially a buried 23-million-year-old mountain. “Fluid is discharging from this outcrop because at some other location there’s fluid flowing from the bottom of the ocean into the earth,” notes Anne Hartwell, a marine research scientist with the University of Alaska Fairbanks. Just where that fluid is entering isn’t known, nor is the path that the water takes through the earth.
But geoscientists were curious about the fluid discharge, so in 2013 they visited the site. Images captured by the remote-controlled research vehicle Jason II revealed a wealth of brooding octopuses clinging onto the side of the outcrop. “Everyone thought they were cool, but no one really did anything about it,” Hartwell says. “There were biologists on board, but they were microbiologists.”

Hartwell wasn’t on that trip, but she was on another one a year later and visited the site in the research submarine ALVIN. “When I got to the seafloor … there was so much life,” she recalls. The octopuses weren’t even the highlight for her. “I saw sea sponges and sea stars and crabs and shrimp. And they were colorful,” she adds. “I hadn’t expected that type of macrofauna, big organisms, that deep,” she says. “And then the octopuses were there, and it was just, ‘whoa, this place is cool!’”

Those octopuses intrigued Hartwell, so she teamed up with one of the geoscientists on that original cruise, Geoffrey Wheat of the University of Alaska Fairbanks, and cephalopod expert Janet Voight of the Field Museum in Chicago. They examined hours of video and still images and other data collected on the two deep-sea missions.
The research team determined that the octopuses are a species of Muusoctopus, a not-well-known genus of deep-sea octopods. Hundreds of these individuals were seen during the two expeditions, including many that had cemented themselves to the outcrop and some of which appeared to be brooding eggs.

Those octopuses had attached themselves in an area of occasional fluid discharge. That fluid is 10 degrees Celsius warmer than the surrounding waters (which are a constant, and chilly, 2° C), and it contains less oxygen.

“I had initially assumed that … they really wanted to be there,” says Hartwell. It wasn’t until she took a closer look at the evidence and consulted with Voight that it became clear that the octopuses are physiologically stressed when they’re in the fluid, she says. The moms may have settled there when no fluid was flowing and are stuck when conditions change. The species should be well adapted to the cold, higher-oxygen conditions found in the deep ocean. And when they find themselves out of their normal element, the octopuses, and their young, probably don’t survive, the team reports in the May issue of Deep Sea Research I.

But it’s not all bad news. Hartwell and her colleagues think that the doomed cephalopods are an indicator of a larger population nearby. In some cases, there were just arms or part of a mantle sticking out of the rock. “That was our evidence that there were octopuses that could fit inside spaces available on this outcrop, and these spaces are notably not associated with any fluid discharge,” Hartwell says.

She is reluctant, though, to say that such a population really exists. “Because we can’t see it, we have no way of knowing whether they’re there or not,” Hartwell cautions. She hopes that scientists might one day be able to revisit the outcrop and poke around for those hidden octopuses. In the meantime, she’s working to classify the rest of that colorful community that so dazzled her deep beneath the surface of the ocean.

Brooding birds from chickadees to ostriches sit squarely on their eggs. But scientists thought some of the heftier dinosaur ancestors of birds might not be able to do that without crushing the clutches. Now, a new study finds that certain dinos with a little extra junk in the trunk also had a clever brooding strategy: They sat within an open space at the center of a ring of eggs, rather than right smack on top of them.

The researchers studied about three dozen fossilized egg clutches belonging to different species of oviraptorosaurs, a group of feathered meat-eating dinosaurs. Clutches laid by larger oviraptorosaur species also had the largest openings at the center, a team led by paleontologist Kohei Tanaka of Nagoya University Museum in Japan reports May 16 in Biology Letters.
Although it’s not possible to determine the exact species of oviraptorosaur from the eggs alone, the researchers divided the eggs into three classifications based on size. The smallest eggs, at less than 170 millimeters long, were assigned to the group Elongatoolithus, which likely included species with body masses ranging from a few tens of kilograms up to 100 or 200 kilograms — similar to today’s ostriches and emus. Medium-sized eggs were assigned to the group Macroolithus and the largest eggs, more than 240 millimeters long, to the group Macroelongatoolithus. The dinos that laid the biggest eggs may have had body masses as high as about 2,000 kilograms.

The team then measured the diameter of the clutch and — if there was one — the diameter of the hole at the center of the clutch. For the largest species, the hole took up most of the area of the clutch, the team found. That, the researchers say, allowed the biggest oviraptorosaur parents to plop themselves in the center of the clutch, reducing the weight load on the eggs while still keeping the eggs warm. No modern birds are known to share that same brooding style.

If Dr. Seuss had been an astronomer, Horton the Elephant (who heard a Who) would have said “a planet’s a planet, no matter how small.”

Even Pluto.

But don’t quote Dr. Seuss to the International Astronomical Union. In 2006, the IAU declared Pluto a planet not.

IAU Resolution B5 (not to be confused with Le Petit Prince’s asteroid B 612) declared that in order to be considered a planet, a body must clear the neighborhood around its orbit. Pluto, then, doesn’t qualify, because its “neighborhood” (way out beyond the orbit of Neptune) is populated by other bodies referred to as trans-Neptunian or Kuiper Belt objects. Two of them, Haumea and Makemake, have been recognized as “dwarf planets,” the same designation that the IAU now applies to Pluto.
This demotion of Pluto to dwarf status (no offense intended to dwarfs) makes sense, IAU defenders contend, because the asteroids (orbiting the sun mostly between Mars and Jupiter) aren’t planets, either — no one of them has cleared out the orbital neighborhood. After all, nobody would call an asteroid a PLANET. Except actually, nearly everybody called them planets for 150 years after they were discovered. Only half a century or so ago did astronomers stop considering most asteroids to be planets. And that shift had nothing to do with clearing out any neighborhoods, Philip Metzger of the University of Central Florida and colleagues point out in a new paper.

“The planetary science community did not reclassify asteroids on the basis of their sharing of orbits, which had been known … since the mid-19th century,” write Metzger and coauthors (including Alan Stern of the Southwest Research Institute in Boulder, Colo.). “Rather, they were reclassified beginning in the 1950s on the basis of new data showing asteroids’ geophysical differences from large, gravitationally rounded planets.”
When astronomers first discovered asteroids (Ceres and Pallas, in 1801 and 1802), the famous astronomer William Herschel did not consider them planets. He called them asteroids because they were “starlike,” too small to appear through his telescope as bigger than a point. All previously known planets (Mercury, Venus, Mars, Jupiter, Saturn and Uranus) appeared as discernible disks. Those (except Uranus) had been known since ancient times; the Greeks called them “planets,” the word for “wanderers,” because they moved through the constant background patterns of the “fixed” stars.

After Herschel, though, everybody else generally referred to the asteroids as planets, since they orbited the sun (unlike moons, which orbited other planets). In 1845, for instance, the prominent scientist Alexander von Humboldt wrote in his masterwork Kosmos that the solar system consisted of 11 “primary planets,” five of them asteroids. (In the 1858 English version, a translator’s note updated that number to 16, adding four more asteroids plus Neptune.) Soon dozens more were added to the asteroid total. By the end of the 19th century hundreds of asteroids had been detected, and they were frequently referred to as “minor planets.” Metzger and colleagues scoured the astronomical literature since 1800 and found that astronomers consistently referred to asteroids as planets. Only Herschel, and in no case anyone after him, complained that shared orbits should disqualify asteroids from planetary status.

In 1951, Metzger and colleagues note, the authoritative Science News-Letter (now Science News, of course) proclaimed that “there are thousands of known planets circling our sun,” designating the big ones as “the chief planets” (including Pluto, discovered in 1930). Other astronomy writers held a similar view. In 1959, the prolific science popularizer Isaac Asimov noted that some preferred to call asteroids “planetoids” (because they are not, in fact, starlike). “Even planetoid isn’t quite a fair name,” Asimov wrote. “The planetoids do not merely have the form of planets; they are planets. To emphasize their small size, though, they are frequently called minor planets and that is perhaps the best name of all.”

But in the 1960s, Metzger and colleagues note, use of “minor planets” diminished as better observations revealed geophysical distinctions between the smaller asteroids and the major planets. Small asteroids had irregular shapes rather than the approximate roundness of big planets. And spectroscopic analyses of asteroid composition plus new ideas about how asteroids formed suggested that most of them were not really very much like planets after all.

“This history indicates that it was geophysical characteristics, not sharing of orbits, that led to the shift in terminology in which asteroids were no longer called planets,” Metzger and collaborators conclude.

Metzger, Stern and coauthors do not say anything about Pluto in their paper. But the implication is obvious: Denying planet status to Pluto is an arbitrary determination (by the IAU) based on a definition without justification in the astronomical literature. It was concocted and voted on at a big meeting, not derived from actual scientific usage. Planetary status should be determined, as it was with asteroids, by the progression of astronomical science, not by voting on an arbitrary definition.

“Voting on key taxonomical terminology and the relationships between taxa is anathema in science,” Metzger and colleagues write. It’s “contrary to the traditions evolved over many centuries to reduce social, political and personal cognitive biases in science. It injects unhelpful dynamics and social pressures into science and impinges on individual scientists’ taxonomical freedom…. We recommend that, regarding planetary taxonomy, central bodies such as the IAU do not resort to voting to create the illusion of scientific consensus.”

But don’t expect the issue about Pluto’s status to be resolved anytime soon. It’s not a case where the question is complicated but the answer is simple. Nevertheless, by reading through the historical literature on planets and asteroids, Metzger and colleagues have improved the prospects for a better-informed debate. After all, “The more that you read, the more things you will know. The more that you learn, the more places you’ll go.”

For much of life’s reign on Earth, organisms got by without skeletons. But since that innovation evolved about 550 million years ago, there’s been an evolutionary arms race of epic proportions.

One of the first competitors was Cloudina, a small seafloor creature whose exterior skeleton almost certainly evolved in response to predation: In well-preserved groups of fossils, up to a fifth of these critters’ exoskeletons show holes or other evidence of being attacked.
In the eras since, in response to predation and a wide range of other challenges, life has evolved a wild diversity of such structures, as described in the aptly named Skeletons. The book is another collaboration between paleobiologists Jan Zalasiewicz and Mark Williams, who previously wrote about oceans on Earth and other worlds (SN: 3/7/15, p. 29). As the authors point out, skeletons now take many forms and sizes, including the tiny carbonate and silicate shells secreted by marine microplankton and the giant frames of blue whales. The authors even make the case that wood — a rigid, biologically built material — is a sort of skeleton.

Zalasiewicz and Williams survey the various functions of skeletons. Exoskeletons, like those of Cloudina, often serve purposes besides body armor, acting as anchors for a creature’s muscles and other tissues. For the first animals that left the seas (and for many creatures living in arid environments today), an exoskeleton helped prevent desiccation.

External skeletons do have their disadvantages. For one thing, an animal like a spider or scorpion that’s fully enclosed in an exoskeleton must occasionally shed its armor as the animal grows, which temporarily leaves the creature vulnerable.
Taking another route, vertebrate animals evolved to grow their skeletons on the inside of the body. Some species, like whales and elephants, can grow to immense proportions but have had to develop different means of defending themselves.

Zalasiewicz and Williams don’t limit their survey to biological scaffolding. As humans developed new technologies, synthetic skeletons emerged — and are “evolving” at an increasingly rapid pace, from the metallic exoskeletons that protected medieval knights to today’s wearable robotic devices that help paraplegics walk (SN: 11/16/13, p. 22).

Overall, the book provides a fascinating look at skeletons throughout the ages and into the future.

Guatemala’s Fuego volcano erupted explosively on June 3, sending hot gas and rock racing downhill in what’s known as a pyroclastic flow. At least 69 people were killed. Emergency officials are trying to reach buried villages to assess the scope of the disaster, but Fuego is already the world’s deadliest eruption of 2018.

The tragedy offers a grim reminder of the many dangers posed by volcanic eruptions. While pyroclastic flows figure prominently in an exhaustive list published last year by British scientists, there are many other potential threats including toxic gas and lava flows. The scientists analyzed how nearly 280,000 people have died in eruptions, including about 62,600 deaths from indirect causes such as famine and disease in the aftermath, since the year 1500.

Nearly half of the total number of direct deaths, or about 125,000, came from just seven eruptions. They include the 1883 eruption of Krakatau, in Indonesia, that swept away approximately 36,000 in a tsunami triggered by the eruption. The 1815 eruption of Tambora, also in Indonesia, killed an estimated 12,000 people right away. (Indonesia has more people living near active volcanoes than any other country.)

Globally, there are around 1,500 active volcanoes, with about 800 million people living within 100 kilometers of one. The new database breaks out information on how far from each eruption people have died.
Within 5 kilometers of a volcano, one danger is being hit by flying rocks, which fall into a hazard category volcanologists call “ballistics.” In 2014, 57 hikers on Japan’s Mount Ontake were killed this way. So, too, were six volcanologists and three other people at Colombia’s Galeras volcano in 1993.

At about 10 kilometers from an eruption, pyroclastic flows — the incendiary clouds of ash and rock that descend at screaming-fast speeds — are particularly deadly. On the Caribbean island of Martinique in 1902, a pyroclastic flow from Mount Pelée killed nearly all 28,000 people in a nearby town; the few survivors included a prisoner saved by his protective cell. For the recent eruption of Guatemala’s Fuego, one of the most active volcanoes in Central America, pyroclastic flows appear to account for most of the 69 fatalities reported so far. (These deaths were not included in the study or in the graphics in this article.)
At greater distances, the deadliest hazards include mudflows called lahars, caused when an eruption melts ice atop a volcano, and tsunamis set off by eruptions. In 1985, the Nevado del Ruiz volcano in Colombia erupted and sent lahars rushing down its slopes, killing some 24,000 people.
“Pinpointing these lethal ranges is quite important” to help emergency officials better prepare, says Sarah Brown, a volcanologist at the University of Bristol in England who led the analysis. Her team is now developing educational films on volcanic hazards and having them translated into languages such as Indonesian.

This spring, many of the most dramatic volcano images have come from Kilauea, on the Big Island of Hawaii, which began spurting lava into housing developments. But no one has been killed at Kilauea. Instead, the disaster in Guatemala has shown where the real danger lies.

Migraines have plagued humans since time immemorial. Now a new migraine prevention treatment, recently approved by the U.S. Food and Drug Administration, promises long-awaited relief from the debilitating condition. But whether the drug will turn out to be a real solution for the 1 in 7 Americans who suffer from migraines, severe headaches that often come with nausea and visual auras, isn’t yet clear. Here’s what we know, and don’t know, about the new therapy.

How does the drug work in the body?
The new drug, Aimovig, generically called erenumab, is a type of monoclonal antibody treatment, a class of medications that resemble the antibodies that the body naturally produces to bind to infectious pathogens.

These treatments work by using specially designed antibodies to target specific proteins and their receptors that contribute to disease. Aimovig, released by pharmaceutical companies Amgen Inc. and Novartis, targets the receptor for a protein called calcitonin gene-related peptide, or CGRP, that is increased in people suffering a migraine attack.

The protein is released from nerve endings throughout the body, including in the meninges, the membranes that surround the brain. When it attaches to the receptor, CGRP widens blood vessels and can contribute to inflammation and pain transmission. Aimovig, delivered once a month with an EpiPen-like injector, works by blocking the receptor for CGRP, reducing pain.

Blocking the protein’s receptor is kind of like putting gum in a lock, says Elizabeth Loder, a neurologist at Brigham and Women’s Hospital in Boston and at Harvard Medical School. The CGRP protein “key” is still floating around, but it can’t become activated.
Could the new drug be a better solution for migraine sufferers?
Most medications currently used to prevent migraines were created for other health issues, including high blood pressure, depression and epilepsy. Many of these drugs are only somewhat effective for migraines, and can have severe side effects including extreme drowsiness and brain fog. Unlike most current medications, Aimovig seems to have fewer daily side effects, which may mean that people take it more regularly and can stay on it for longer periods of time.

On average, Aimovig reduces the number of migraines by one to two each month, which is on par with current migraine medications. “It would be great if we had a new treatment that works substantially better than the treatments we now have,” says Loder, “but that is not the case here.”

There is also a potential barrier to Aimovig: cost. Amgen and Novartis are currently offering two free doses to eligible patients, but after that the medication costs $6,900 per year for people paying out of pocket.

What questions remain about the drug?
Because Aimovig is new, there’s much researchers don’t know about it. Long-term effects on people, for example, will have to be followed closely, says Matthew Robbins, a neurologist at Montefiore Medical Center in New York City. This is especially crucial in chronic migraine patients, who may be taking the medication for decades.

And as with many types of drugs, scientists don’t know how the medication will affect pregnant women (SN Online: 5/30/18). The FDA isn’t telling pregnant women not to use the drug, but the agency is making Amgen monitor for the next several years outcomes in pregnant women who use the drug. The drug can take some time to clear the body, so women who are trying to conceive and don’t want Aimovig in their system should discontinue treatment at least five months before becoming pregnant, says neurologist David Dodick of the Mayo Clinic in Phoenix. Dodick participated in the design and analysis of the Aimovig clinical trials.

There is also uncertainty about whether the drug will have side effects for people with cardiovascular issues, such as high blood pressure or coronary artery disease. Sometimes, CGRP can be good for the body — the protein helps relax arteries, including around the heart, and leads to better blood flow and a lower heart rate. The bodies of people taking Aimovig, a CGRP receptor blocker, may not be able to perform these essential functions in a cardiovascular emergency.

There is a theoretical risk that blocking CGRP’s action could lead to a heart attack or stroke, Dodick says, but that hasn’t been observed in any of the thousands of patients who have been treated in clinical trials.

Are there other similar drugs being developed?
Aimovig is the first CGRP monoclonal antibody treatment to be approved by the FDA, but it might not be alone for long. Eli Lilly, Teva Pharmaceutical Industries and Alder Biopharmaceuticals are all in the midst of clinical trials for similar drugs. Instead of targeting CGRP’s receptor, these medications target the protein itself. They will also be delivered by differing mechanisms: Some, like Aimovig, will be given via injection, while others might need to be administered through an infusion at the hospital.

The long search for gravitational waves … may be in the final lap…. Rotating binary stars or, perhaps, other galaxies like the Milky Way but far beyond it, or the center of the Milky Way itself, are likely sources for gravitational radiation. — Science News, June 22, 1968.

Update
Although Joseph Weber, a physicist at the University of Maryland, announced a gravity wave detection in 1969, no one could verify his claim. It took almost another 50 years for researchers to directly detect gravitational waves (SN: 3/5/16, p. 24). Those spacetime ripples from two merging black holes, glimpsed by the Advanced Laser Interferometer Gravitational-Wave Observatory, or LIGO, confirmed Einstein’s theory of gravity. Scientists have since spotted more gravitational waves from black holes (SN: 10/28/17, p. 8), as well as from colliding neutron stars (SN: 11/11/17, p. 6). A trio of spacecraft called LISA, slated to launch in 2034, will continue the search from space (SN Online: 6/20/17).

The Pillars of Creation may keep standing tall due to the magnetic field within the star-forming region.

For the first time, scientists have made a detailed map of the magnetic field inside the pillars, made famous by an iconic 1995 Hubble Space Telescope image (SN Online: 1/6/15). The data reveal that the field runs along the length of each pillar, perpendicular to the magnetic field outside. This configuration may be slowing the destruction of the columns of gas and dust, astronomer Kate Pattle and colleagues suggest in the June 10 Astrophysical Journal Letters.
Hot ionized gas called plasma surrounds the pillars, located within the Eagle Nebula about 7,000 light-years from Earth. The pressure from that plasma could cause the pillars to pinch in at the middle like an hourglass before breaking up. However, the researchers suggest, the organization of the magnetic field within the pillars could be providing an outward force that resists the plasma’s onslaught, preventing the columns from disintegrating.
The team studied light emitted from the pillars, measuring its polarization — the direction of the wiggling of the light’s electromagnetic waves — using the James Clerk Maxwell Telescope in Hawaii. Dust grains within the pillars are aligned with each other due to the magnetic field. These aligned particles emit polarized light, allowing the researchers to trace the direction of the magnetic field at various spots.
“There are few clear measurements of the magnetic fields in objects like pillars,” says Koji Sugitani of Nagoya City University in Japan. To fully understand the formation of such objects, more observations are needed, he says.
Studying objects where stars are born, such as the pillars, could help scientists better understand the role that magnetic fields may play in star formation (SN: 6/9/18, p. 12). “This is really one of the big unanswered questions,” says Pattle, of National Tsing Hua University in Hsinchu, Taiwan. “We just don’t have a very good idea of whether magnetic fields are important and, if they are, what they are doing.”

People inhabited what’s now central Texas several thousand years before hunters from North America’s ancient Clovis culture showed up, researchers say.

Excavations at the Gault site, about 64 kilometers north of Austin, produced a range of stone artifacts that date to between around 16,700 and 21,700 years ago, reports a team led by archaeologist Thomas Williams of Texas State University in San Marcos. An analysis of 184 of those finds identified 11 spearpoints unlike any others that have been found at ancient American sites, the scientists conclude July 11 in Science Advances.
Researchers have long argued about whether people reached North America before the rise of Clovis culture 13,000 years ago. Evidence from the Gault site joins other recent reports of humans venturing deep into North America far earlier (SN: 6/11/16, p. 8), which would take Clovis people out of the running for the title of first New World settlers.

Williams’ group estimated the age of the Gault pre-Clovis discoveries with a method that calculates the time since artifact-containing sediment has been exposed to sunlight.

Previous work at the Gault site uncovered Clovis spearpoints and other implements from roughly 13,000 years ago, as well as tools and other artifacts made by groups dating to as recently as a few thousand years ago. Some of the newly described stone tools at Gault, such as small, rectangular cutting implements, display similarities to Clovis tools, the investigators say. Overall, though, the earlier artif