Meanders in river beds help the climate

It takes about 8500 years for a grain of sand from the Andes to be washed across the Argentine lowlands into the Río Paraná. The 1200-kilometer journey in the river called Río Bermejo is interrupted by many stops in river floodplains, where the grain is deposited, sometimes over thousands of years, and then washed free again. The sand is accompanied by organic carbon, washed in from soil and plants. The transport in water thus gains relevance for the climate: Rivers carry the carbon, which was previously removed from the atmosphere via photosynthesis, as sediment into the sea, where it is stored for thousands of years without harming the climate.

Researchers at the GFZ German Research Centre for Geosciences have now quantified the individual processes of the journey for the first time and report on them in the journal Nature Geoscience. An important result of the work: It is in particular undisturbed meandering sections of a river where carbon is deposited and reabsorbed, and then transported further into the sea. In river sections with straight, stable banks, on the other hand, only the suspended particle load passes through, while the carbon in the river floodplains is slowly decomposed again to CO2 by microorganisms. GFZ working group leader Dirk Sachse says, "The Río Bermejo was an ideal natural laboratory for us because it has no significant tributaries." Sachse is also director of the "Landscapes of the Future" topic in the Helmholtz program "Changing Earth -- Sustaining Our Future." He says, "This means that natural river courses that have space to erode floodplains can remove more carbon from the atmosphere than straight river sections. In this respect, straightening of rivers by humans could also contribute to the increase in atmospheric CO2 concentration. What's exciting now is answering the question of whether we can help the climate by giving rivers more space again and not impeding natural river meandering."

The international team led by first author Marisa Repasch of GFZ studied the processes in the river and its floodplains with a diverse set of instruments. Analyses of cosmogenic beryllium-10 content, for example, indicated the duration of sediment transport. Dating based on the unstable carbon isotope 14C, in turn, allowed conclusions to be drawn about the age of the particles of organic origin. During fieldwork in Argentina, samples were taken from the river at multiple stations along the source-to-sink pathway. "Naturally meandering rivers erode material from floodplains and transport it to the sea, where it remains for a long time," says Marisa Repasch, summarizing the results, "in contrast, artificially stabilized river courses are far less effective carbon sinks."

From Science Daily

New species of human ancestor named: Homo bodoensis

An international team of researchers, led by University of Winnipeg palaeoanthropologist Dr. Mirjana Roksandic, has announced the naming of a new species of human ancestor, Homo bodoensis. This species lived in Africa during the Middle Pleistocene, around half a million years ago, and was the direct ancestor of modern humans.

The Middle Pleistocene (now renamed Chibanian and dated to 774,000-129,000 years ago) is important because it saw the rise of our own species (Homo sapiens) in Africa, our closest relatives, and the Neanderthals (Homo neanderthalensis) in Europe.

However, human evolution during this age is poorly understood, a problem which paleoanthropologists call "the muddle in the middle." The announcement of Homo bodoensis hopes to bring some clarity to this puzzling, but important chapter in human evolution.

The new name is based on a reassessment of existing fossils from Africa and Eurasia from this time period. Traditionally, these fossils have been variably assigned to either Homo heidelbergensis or Homo rhodesiensis, both of which carried multiple, often contradictory definitions.

"Talking about human evolution during this time period became impossible due to the lack of proper terminology that acknowledges human geographic variation" according to Roksandic, lead author on the study.

Recently, DNA evidence has shown that some fossils in Europe called H. heidelbergensis were actually early Neanderthals, making the name redundant. For the same reason, the name needs to be abandoned when describing fossil humans from east Asia according to co-author, Xiu-Jie Wu (Institute of Vertebrate Paleontology and Paleoanthropology, Beijing, China).

Further muddling the narrative, African fossils dated to this period have been called at times both H. heidelbergensis and H. rhodesiensis. H. rhodesiensis is poorly defined and the name has never been widely accepted. This is partly due to its association with Cecil Rhodes and the horrendous crimes carried out during colonial rule in Africa -- an unacceptable honour in light of the important work being done toward decolonizing science.

The name "bodoensis" derives from a skull found in Bodo D'ar, Ethiopia, and the new species is understood to be a direct human ancestor. Under the new classification, H. bodoensis will describe most Middle Pleistocene humans from Africa and some from Southeast Europe, while many from the latter continent will be reclassified as Neanderthals,

The co-first author Predrag Radovic (Faculty of Philosophy, University of Belgrade, Serbia) says, "Terms need to be clear in science, to facilitate communication. They should not be treated as absolute when they contradict the fossil record."

Read more at Science Daily

Fossil dental exams reveal how tusks first evolved and why they are unique only to mammals

Most people picture an elephant when imagining animals with tusks. But many other animals have tusks including warthogs, hippopotamuses, Arctic-dwelling walruses, and even a five-pound, guinea pig looking animal called hyraxes. Though the size of the animal and their tusks can vary they all have one unique thing in common in that they are only found on mammals -- there are no known fish, reptiles, or birds with tusks. Despite being an iconic feature of modern and fossil mammals the mystery remains of what evolutionary steps led to the development of this dental phenomenon and why are mammals the only animals today with tusks?

In a new paper published October 27 in the Proceedings of the Royal Society B researchers trace the first tusks back to ancient mammal relatives that lived before the dinosaurs and shed light on the evolution of mammalian tusks by first defining what makes a tusk a tusk.

"Tusks are this very famous anatomy, but until I started working on this study, I never really thought about how tusks are restricted to mammals," said lead author Megan Whitney, postdoctoral fellow in the Department of Organismic and Evolutionary Biology, Harvard University.

"We were able to show that the first tusks belonged to animals that came before modern mammals, called dicynodonts," said Kenneth Angielczyk, co-author and curator at Chicago's Field Museum. "They're very weird animals."

Dicynodonts, though not mammals, are distant relatives and are more closely related to mammals than dinosaurs and other reptiles. Dicynodonts lived between 270-201 million years ago and included a diverse range of animals from tiny rat-like dicynodonts to huge elephant-sized dicynodonts. They are known for having a very peculiar arrangement of teeth. A defining feature of these animals, first discovered 176 years ago, is the protruding tusks in their upper jaws. Most had two upper tusks that came down from the canine position, but they rarely had additional teeth. Instead, dicynodonts had a beak at the front of their mouths that was made of keratin and resembled a turtles beak.

The researchers were taking a lunch break during a paleontological dig when they got the idea for the study. "We were sitting in the field in Zambia, and there were dicynodont teeth everywhere," recalls Whitney. "I remember Ken picking them up and asking how come they were called tusks, because they had features that tusks don't have."

Not all protruding teeth are technically tusks. "For this paper, we had to define a tusk, because it's a surprisingly ambiguous term," said Whitney. The researchers determined that for a tooth to be a tusk it must extend out from the mouth, be made entirely of dentine -- lacking enamel found on most mammals' teeth, and is ever-growing.

The researchers performed paleohistology (the study of fossil tissues) on paper-thin slices of fossilized teeth from 19 dicynodont specimens, representing ten different species. They used micro-CT to examine how the teeth attached to the skull and to see if there was any evidence of continuous growth.

Some of the dicynodont tusks that the team observed in Zambia didn't seem to fit the definition of a tusk either -- they were coated in enamel instead of dentine. "There are many different kinds of dicynodonts and they appear to mostly all have tusks," said Whitney, "however, when you look at the micro structural details they're very different in those groups." Enamel teeth are tougher than dentine but because of the geometry of how teeth grow in the jaw, if you want teeth that keep growing throughout your life, you can't have a complete enamel covering. Animals like humans evolved durable but hard-to-fix teeth -- there is no replacement for the loss of an adult tooth. Tusks are less durable than enamel-coated teeth, but they grow continuously, even if they get damaged. "Enamel-coated teeth are a different evolutionary strategy than dentine-coated tusks, it's a trade-off," says Whitney.

Analysing the histological thin sections of dicynodont specimens from South Africa, Antarctica, Zambia, and Tanzania the researchers found that, much like human teeth, these animals appeared to reduce the amount of replacement teeth at the canine position and had a soft tissue attachment to the jaw. Interestingly, this is a combination of features that is unique to mammals. Mammals, like humans, replace baby teeth with adult teeth only once unlike most other vertebrates -- for instance sharks have continuous teeth production. Mammal teeth are attached to the jaw by gomphosis which is a soft-tissue, or ligament, attachment. Most vertebrate teeth, however, are attached to the jaw by ankylosis, which is a hard-tissue fusion of bone to tooth.

"If you have these two things, a reduced amount of tooth replacement and a soft-tissue attachment, an ever-growing tooth allows the animal to get around the fact that it cannot replace the tooth. Instead it evolves to continuously deposit the same tooth tissues," said Whitney. "And as the animal continues to deposit the tissue, the tooth begins to move outside of the mouth to become functional."

The researchers found that true tusk evolution only occurred at a later stage of evolution in this group -- early members of this group had a big tooth rather than a true tusk. Late in their evolutionary history dicynodonts evolved a true tusk that was ever growing, and surprisingly did so convergently in multiple different kinds of dicynodonts. "I kind of expected there to be one point in the family tree where all the dicynodonts started having tusks, so I thought it was pretty shocking that we actually see tusks evolve convergently," said Whitney. "This is a similar story to what we see in elephant evolution in that it mirrors a lot of the patterns that have been studied on how elephants got their tusks."

"Dicynodonts were the most abundant and diverse vertebrates on land just before dinosaur times, and they're famous for their 'tusks.' The fact that in reality only a few have true tusks, and the rest have big teeth, is a beautiful example of evolution we can document. We can see how to build a tusk!" said co-author Brandon Peecook, curator at the Idaho Museum of Natural History.

The researchers say that the study, which shows the earliest known instance of true tusks, could help scientists better understand how evolution works.

"Tusks have evolved a number of times, which makes you wonder how -- and why? We now have good data on the anatomical changes that needed to happen for dicynodonts to evolve tusks. For other groups, like warthogs or walruses, the jury is still out," said co-author Christian Sidor, curator at the University of Washington Burke Museum.

The various kinds of teeth animals have evolved can tell scientists about the pressures those animals faced that could have produced those teeth. For instance tusks can function in a variety of ways including defense, competition, burrowing, sexual selection, and even assist with locomotion -- as in the walrus which uses its tusks to hoist itself upon to the ice from the water. A continuously growing tusk may have allowed these dicynodonts to overcome the challenges of only having one set of replacement teeth throughout their lives.

"We don't really know what functions the dicynodonts tusks may have had because we can't observe them and see what they were doing with them," said Whitney. "That's a lingering question about dicynodonts, even more so now."

Read more at Science Daily

Juno peers deep into Jupiter’s colorful belts and zones

Leicester study of data captured in orbit around Jupiter has revealed new insights into what's happening deep beneath the gas giant's distinctive and colourful bands.

Data from the microwave radiometer carried by NASA's Juno spacecraft shows that Jupiter's banded pattern extends deep below the clouds, and that the appearance of Jupiter's belts and zones inverts near the base of the water clouds. Microwave light allows planetary scientists to gaze deep beneath Jupiter's colourful clouds, to understand the weather and climate in the warmer, darker, deeper layers.

At altitudes shallower than five bars of pressure (or around five times the average atmospheric pressure on Earth), the planet's belts shine brightly in microwave light, whereas the zones are dark. But everything changes at higher pressures, at altitudes deeper than 10 bars, giving scientists a glimpse of an unexpected reversal in the meteorology and circulation.

Dr Leigh Fletcher, Associate Professor in Planetary Science at the University of Leicester and Participating Scientist for the Juno mission, is lead author of the study, published in the Journal of Geophysical Research-Planets. He said:

"One of Juno's primary goals was to peer beneath the cloudy veil of Jupiter's atmosphere, and to probe the deeper, hidden layers.

"Our study has shown that those colourful bands are just the 'tip of the iceberg', and that the mid-latitude bands not only extend deep, but seem to change their nature the further down you go.

"We've been calling the transition zone the jovicline, and its discovery has only been made possible by Juno's microwave instrument."

Among Jupiter's most notable attributes is its distinctive banded appearance. Planetary scientists call the light, whiteish bands zones, and the darker, reddish ones belts. Jupiter's planetary-scale winds circulate in opposite direction, east and west, on the edges of these colourful stripes. A key question is whether this structure is confined to the planet's cloud tops, or if the belts and zones persist with increasing depth.

An investigation of this phenomenon is one of the primary objectives of NASA's Juno mission, and the spacecraft carries a specially-designed microwave radiometer to measure emission from deep within the Solar System's largest planet for the first time.

The Juno team utilise data from this instrument to examine the nature of the belts and zones by peering deeper into the Jovian atmosphere than has ever previously been possible.

Juno's microwave radiometer operates in six wavelength channels ranging from 1.4 cm to 50 cm, and these enable Juno to probe the atmosphere at pressures starting at the top of the atmosphere near 0.6 bars to pressures exceeding 100 bars, around 250 km deep.

At the cloud tops, Jupiter's belts appear bright with microwave emission, while the zones remain dark. Bright microwave emission either means warmer atmospheric temperatures, or an absence of ammonia gas, which is a strong absorber of microwave light.

This configuration persists down to approximately five bars. And at pressures deeper than 10 bars, the pattern reverses, with the zones becoming microwave-bright and the belt becoming dark. Scientists therefore believe that something -- either the physical temperatures or the abundance of ammonia -- must therefore be changing with depth.

Dr Fletcher terms this transition region between five and 10 bars the jovicline, a comparison to the thermocline region of Earth's oceans, where seawater transitions sharply from relative warmth to relative coldness. Researchers observe that the jovicline is nearly coincident with a stable atmospheric layer created by condensing water.

Dr Scott Bolton, of NASA's Jet Propulsion Laboratory (JPL), is Principal Investigator (PI) for the Juno mission. He said:

"These amazing results provide our first glimpse of how Jupiter's famous zones and belts evolve with depth, revealing the power of investigating the giant planet's atmosphere in three dimensions."

There are two possible mechanisms that could be responsible for the change in brightness, each implying different physical conclusions.

One mechanism is related to the distribution of ammonia gas within the belts and zones. Ammonia is opaque to microwaves, meaning a region with relatively less ammonia will shine brighter in Juno's observations. This mechanism could imply a stacked system of opposing circulation cells, similar to patterns in Earth's tropics and mid-latitudes.

These circulation patterns would provide sinking in belts at shallow depths and upwelling in belts at deeper levels -- or vigorous storms and precipitation, moving ammonia gas from place to place.

Another possibility is that the gradient in emission corresponds to a gradient in temperature, with higher temperatures resulting in greater microwave emission.

Temperatures and winds are connected, so if this scenario is correct, then Jupiter's winds may increase with depth below the clouds until we reach the jovicline, before tapering off into the deeper atmosphere -- something that was also suggested by NASA's Galileo probe in 1995, which measured windspeeds as it descended under a parachute into the clouds of Jupiter.

Read more at Science Daily

The early bird gets…the truffle? Birds hunt for fungi, too

Humans like truffles, as do many mammals. Now new evidence suggests that birds may also seek out and disperse these ecologically important fungi.

A study conducted by University of Florida researchers found that two common ground-dwelling bird species in Patagonia regularly consume truffles and pass on viable truffle spores through their feces.

"Truffles are essentially mushrooms that grow underground. Unlike aboveground mushrooms, which release their spores into the air, truffles depend on animals consuming them to spread their spores," said Matthew E. Smith, senior author on the study and an associate professor in the UF/IFAS plant pathology department.

"Previously, it was assumed that only mammals consumed and dispersed truffle spores, so our study is the first to document birds doing this as well," said Marcos Caiafa, first author of the study, who recently received a doctorate in plant pathology from the UF/IFAS College of Agricultural and Life Sciences. Smith was Caiafa's dissertation adviser.

The term "truffle" includes hundreds of species of underground fungi, only a few of which are the truffles people associate with high-end cuisine. While non-culinary truffles may not appeal to human foodies, each has evolved to attract different animals that can assist in its spread.

The spreading of truffle spores is an important part of a healthy forest ecosystem, Smith said, as many tree species have a symbiotic relationship with truffles, which colonize the roots of the trees.

"These fungi form mycorrhizas, a relationship whereby the fungus helps the plant take up nutrients in exchange for sugars from the plant," explained Caiafa, who is now a postdoctoral researcher at the University of California, Riverside.

The bird species they studied -- chucao tapaculos and black-throated huet-huets -- not only eat truffles but appear to search them out specifically. In the past these birds were known to eat invertebrates, seeds and fruits, but their consumption of fungi was not previously documented, the researchers said.

"The questions about birds and truffles emerged during an earlier research project in Patagonia. We are working in the forest, raking the soil and digging up the truffles, and we notice these birds keep following us around and checking out the areas where we had disturbed the soil. Then we find truffles with chunks pecked out of them. Marcos even saw a bird eat a truffle right in front of him. All of this led us to ask, are these birds hunting for truffles?" Smith said.

To confirm this hypothesis, the research team collected the droppings of chucao tapaculos and black-throated huet-huets and tested them for truffle DNA. They found truffle DNA in 42% of chucao tupaculo and 38% of huet-huet feces. They also used a special microscope technique, fluorescent microscopy, to confirm that the spores in the feces were viable, suggesting that the birds are spreading truffles to new areas.

"DNA-based diet analysis is exciting because it provides new insights into interactions between organisms that would otherwise be difficult to directly observe," said Michelle Jusino, one of the study's co-authors and a former postdoctoral researcher in Smith's lab.

"And, because sampling feces does not negatively impact the target species, I think these methods are invaluable for studying and protecting both common and rare species in the future," said Jusino, who is now a research biologist with the U.S. Forest Service Northern Research Station's Center for Forest Mycology Research.

The study's authors think that some truffles in Patagonia may have evolved to attract birds.

"Some of truffles that the birds eat are brightly colored and resemble local berries. Our future research may look to see if there is an evolutionary adaptation there -- that the truffles have evolved to look more like the berries that the birds also eat," Smith said.

Read more at Science Daily

Runoff, sediment flux in High Mountain Asia could limit food, energy for millions

Rivers flowing from the Tibetan Plateau and the surrounding high Asian mountains which support one-third of the world's population have experienced rapid increases in annual water and sediment runoff since the 1990s, and the volume of sediment washed downstream could more than double by 2050 under the worst-case scenario, a team of scientists has found.

The cause is "amplified warming": Since 1950, the High Mountain Asia area, or the region of Asia containing five mountain ranges including the Himalaya and Hindu Kush around the Tibetan Plateau, has warmed by about 2 degrees Celsius, twice the amount of warming worldwide. That warming is precipitating more glacier melt, permafrost thaw while annual rainfall is also increasing, the researchers note.

"These findings have far-reaching implications for the region's hydropower, food and environmental security," the researchers observe. The findings also highlight the under-appreciated importance of sediment fluxes and have implications for potential changes in the global carbon cycle, they add.

The research, published today in the journal Science, is led by the National University of Singapore and includes three researchers from the University of Colorado Boulder, including Irina Overeem, Jaia Syvitski and Albert Kettner, all researchers in the Institute of Arctic and Alpine Research. Overeem is also a CU Boulder associate professor of geological sciences, and Syvitski is professor emeritus of geological sciences.

The scientists analyzed observational data of runoff and sediment fluxes from 28 headwater basins over the past six decades.

Sediment flux is the mass of sediment that passes through a specific point in a river basin over a given time period, "like truckloads of sand being transported, in this case by water," Overeem said. Although river runoff, the amount of water entering a river system, and sediment flux are both increasing, they are rising at different rates.

In the river basins the scientists studied, runoff increased by about 5% per decade, while sediment flux increased about 12% per decade.

Overeem explained the variability is affected in two ways: "With glacial melt and permafrost thaw there are new sources of sediment, that previously had been frozen in place in the landscape now can slump into the river. In addition, if more rainfall triggers bigger floods, you suddenly have exceeded a threshold and you can pick up so much more sediment" compared to average conditions. "If you increase the source and the proportion of a couple of these extreme events, you'll get disproportionally much more sediment. So that is maybe what's going on in this system."

River-borne sediment can benefit highly populated areas like Bangladesh, where sediment helps maintain the coastal zone. But in other areas such as Tibet or Nepal, which have hydro-electric power plants, rising levels of sediment can wear out the dams' turbines and fill reservoirs with sand and silt.

By harming existing or planned hydropower projects and reducing irrigation capacity, rising sediment fluxes can thus "threaten the region's food and energy security," the authors write. Additionally, the rising levels of sediment, which can carry nutrients, pollutants and organic carbon, can have implications for water quality and flooding, potentially affecting millions of people.

Research on the High Mountain Asia watershed was facilitated by the area's unusually good, long-term records of streamflow and sediment flux, Overeem said, adding that datasets of similar quality do not exist for Greenland or the whole Arctic.

In the Arctic, scientists have also recorded increases in water discharge from melting ice and increasing rainfall but have few measurements of sediment flux.

Read more at Science Daily

The goal in mind

Scientists discover the brain's internal goal map enabling animals to navigate precisely to a chosen destination.

Animals including rodents and humans can navigate to a desired location by relying on the brain's internal cognitive map. While previous studies have identified specialized neurons that help us identify our own position and direction in space, whether the brain can process a precise estimate of a future target location has been a long-standing question. Scientists at the Max Planck Institute for Brain Research in Frankfurt have now discovered a neural code for spatial goals, demonstrating the existence of the brain's goal map guiding us toward a remote destination over space and time.

An internal compass

To perform a simple daily chore such as planning a trip to a local supermarket, you need to visualize the supermarket in your mind while you are still at home so that your brain can compute the best route for the upcoming journey. But how can the brain's spatial map simultaneously represent two locations in space -- your home that can be perceived with most of your senses, and the supermarket that is located beyond the range of your sensory perception? Neuroscientists have grappled with this question for the last 50 years.

"Since the Nobel prize winning discovery of place cells in 1971 by John O'Keefe and colleagues, spatial navigation research has primarily focused on the properties of neurons tuned to the animal's instantaneous position or direction," says Hiroshi Ito, research group leader at the Max Planck Institute for Brain Research who headed the new study published in Nature. Previous research in the last decades has provided us with a better understanding of how we can keep track of our position and direction in space. However, the evidence for goal estimation -- another fundamental aspect of spatial navigation -- has almost entirely been missing so far.

"Our present work addressed this puzzle by showing that future goals are represented as a pattern of neural activity resembling the ones during previous visits to a target location (e.g. supermarket). For example, a specific pattern of neural activity is observed when an animal visits a particular location in space. However, we found that this activity pattern can re-emerge merely upon the animal's decision to target the same location as a navigational goal, irrespective of where the animal is actually located," says Ito.

"We designed a task in which a rat needs to navigate to a remote location where a reward is provided. Notably, the reward location keeps changing, which ensures that the rat continuously updates its goal locations," explains Raunak Basu, the postdoc in the Ito lab and first author of the new study. As a candidate brain region representing a future goal, the scientists focused on the orbitofrontal cortex (OFC) -- a subregion of the prefrontal cortex -- that is thought to be involved in decision making, yet remains relatively unexplored from the aspect of spatial navigation.

Deciphering a neural code for future goals

To investigate neural patterns in the OFC, the researchers simultaneously measured the activity of hundreds of neurons. "We achieved this by using custom-built 3-D printed recording devices that can insert up to 60 ultra-thin wires (called tetrodes) in the rat's brain. These devices enabled us to monitor OFC neural activity patterns from when the rats were about to start their journey until they reached the goal location. With the help of statistical decoding techniques, we confirmed that these patterns share significant similarities, demonstrating that the future goal is represented in the OFC throughout the duration of navigation" says Basu.

Perturbation of OFC neurons leads to navigation errors

Fueled by their discovery, Basu and colleagues asked whether the activity of OFC neurons causally influences the animal's destination. To this end, they perturbed the activity of neurons in the OFC by applying pulsed laser light at the start of the journey. "I was most surprised to see that the rat that had been performing the navigation task almost perfectly, suddenly upon perturbation, ignorantly walked past a correct goal and headed to an incorrect location," recalls Basu. "This navigation error was reversible once the perturbation stopped, suggesting that the impairment is not due to a general loss of goal memory."

Read more at Science Daily

Why do humans possess a twisted birth canal?

In most women, the upper part, or inlet, of the birth canal has a round or transversely (left-to-right) oval shape, which is considered ideal for parturition, but it is unknown why the lower part of the birth canal has a pronounced longitudinally (front-to-back) oval shape. This twisted shape typically requires the Baby to rotate when passing through the narrow birth canal, which further increases the risk of birth complications.

In comparison with humans, apes have a relatively easy birth pattern that does not require rotation of the baby thanks to the longitudinally oval shape of the birth canal both at its inlet and the outlet. "For giving birth, it would be much easier to have a uniformly shaped birth canal also in our species," says Katya Stansfield, a specialist in biomechanics. Instead, the twisted human shape requires a complex, rotational birth mechanism: The baby needs to rotate to align the longest dimension of its head with the widest dimension of each plane of the birth canal. Misalignment can lead to obstructed labour and result in health risks for both mother and baby.

A research team of evolutionary biologists and engineers from the University of Vienna, the Konrad Lorenz Institute for Evolution and Cognition Research in Klosterneuburg and the University of Porto hypothesised that the support function of the pelvic floor muscles, which are suspended across the lower pelvis and also play an important role in sexual function and continence, may have influenced the evolution of the shape of the birth canal. The team carried out extensive biomechanical modelling of the pelvic floor and found that the highest deformation, stress, and strain occur in pelvic floors with a circular or transverse-oval shape, whereas a longitudinally oval elongation increases pelvic floor stability. "Our results demonstrate that the longitudinally oval lower birth canal is beneficial in terms of stability," says Katya Stansfield. "However, this outcome prompted us to ask why the pelvic inlet in humans is not also elongated longitudinally," elaborates Barbara Fischer, an evolutionary biologist.

Traditionally, it has been assumed that the transverse dimension of the human pelvis is constrained by the efficiency of upright locomotion. "We argue that the transverse elongation of the pelvic inlet has evolved because of the limits on the front-to-back diameter in humans imposed by balancing upright posture, rather than by the efficiency of the bipedal locomotion," says Philipp Mitteroecker, who was also involved in this study. A longitudinally deeper inlet would require greater pelvic tilt and lumbar lordosis, which would compromise spine health and the stability of upright posture. These different requirements of the pelvic inlet and outlet likely have led to the evolution of a twisted birth canal, requiring human babies to rotate during birth.

From Science Daily

Astronomers discover massive galaxy 'shipyard' in the distant universe

Even galaxies don't like to be alone. While astronomers have known for a while that galaxies tend to congregate in groups and clusters, the process of going from formation to friend groups has remained an open question in cosmology.

In a paper published in the Astronomy & Astrophysics Journal, an international team of astronomers reports the discovery of a group of objects that appear to be an emerging accumulation of galaxies in the making -- known as a protocluster.

"This discovery is an important step toward reaching our ultimate goal: understanding the assembly of galaxy clusters, the most massive structures that exist in the universe," said Brenda Frye, an associate professor of astronomy at the University of Arizona's Steward Observatory and a co-author of the study.

The Milky Way, home to our solar system, belongs to a galaxy cluster known as the Local Group, which in turn is a part of the Virgo supercluster. But what did a supercluster such as Virgo look like 11 billion years ago?

"We still know very little about protoclusters, in part because they are so faint, too faint to be detected by optical light," Frye said. "At the same time, they are known to radiate brightly in other wavelengths such as the sub-millimeter."

Initially discovered by the European Space Agency's Planck telescope as part of an all-sky survey, the protocluster described in the new paper showed up prominently in the far-infrared region of the electromagnetic spectrum. Sifting through a sample of more than 2,000 structures that could be in the process of becoming clusters, researchers came across a protocluster designated as PHz G237.01+42.50, or G237 for short. The observations looked promising, but to confirm its identity required follow-up observations with other telescopes.

Led by Mari Polletta at the National Institute for Astrophysics in Milan, Italy, the team conducted observations using the combined power of the Large Binocular Telescope in Arizona, which is managed by UArizona, and the Subaru Telescope in Japan. The team identified 63 galaxies belonging to the G237 protocluster. The original discovery was published in a previous paper, and follow-up observations were also obtained using archival data, the Herschel Space Observatory and the Spitzer Space Telescope.

"You can think of galaxy protoclusters such as G237 as a galaxy shipyard in which massive galaxies are being assembled, only this structure existed at a time when the universe was 3 billion years old," Frye said. "At the same time, the genealogy may be closer than you think. Because the universe is homogeneous and the same in all directions, we think that the Milky Way may have docked at a protocluster node similar to G237 when it was very young."

At first, observations of G237 implied a total star formation rate that was unrealistically high, and the team struggled to make sense of the data. The G237 protocluster seemed to be forming stars at a rate of 10,000 times that of the Milky Way. At that rate, the protocluster would be expected to rapidly use up its stellar fuel and subsequently settle down into a complex system similar to the Virgo supercluster.

"Each of the 63 galaxies discovered so far in G237 was like a star factory in overdrive," Frye said. "It's as if the galaxies were working on overtime to the assemble stars. The rate of production was unsustainable. At such a pace, the supply chains are expected to break in the near future, and in a way that permanently shuts down the galaxy shipyard."

Such high yields could only be maintained by a continuous injection of fuel, which for stars is hydrogen gas. Frye said that would require an efficient and unbroken supply chain that drew in unreasonably large amounts of fresh gas to fuel the star-forming factories.

"We don't know where that gas was coming from," she said.

Later, the team discovered that some of what it was seeing came from galaxies unrelated to the protocluster, but even after the irrelevant observations were removed, the total star formation rate remained high, at least 1,000 solar masses per year, according to Poletta. In comparison, the Milky Way produces about one solar mass each year.

"The picture we have pieced together now is that of a successful galaxy shipyard, which is working at high efficiency to assemble galaxies and the stars within them and has an energy supply that is more sustainable," Frye said.

All galaxies in the universe are part of a giant structure that resembles a three-dimensional spider web shape called the cosmic web. The filaments of the cosmic web intersect at the nodes, which equate to the galaxy shipyards in the analogy.

"We believe that the filaments mediate the transfer of hydrogen gas from the diffuse medium of intergalactic space onto these hungry, newly forming protocluster structures in the nodes," Frye said.

Pointing to future research, Polletta said: "We are in the process of analyzing more observations on this and other Planck protoclusters with the goal of tracing the gas that gives birth to these newly forming stars and feeds the supermassive black holes, to determine its origin and explain the observed extraordinary activity."

Frye said she is looking forward to combining data from the Large Binocular Telescope with observations from NASA's the James Webb Space Telescope, to be launched in December.

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Heatwaves like ‘the Blob' could decrease role of ocean as carbon sink

Researchers have found the two-year heatwave known as 'the Blob' may have temporarily dampened the Pacific's 'biological pump,' which shuttles carbon from the surface ocean to the deep sea where it can be stored for millennia.

Canadian and European researchers, in collaboration with the U.S. Department of Energy Joint Genome Institute, conducted a large-scale study of the impact of one of the largest marine heatwaves on record -- colloquially known as the Blob -- on Pacific Ocean microorganisms. Their observations suggest that it's not just larger marine life that is affected by abrupt changes in sea temperature.

"Heatwaves such as the Blob may decrease the ocean's biological role as a carbon sink for fixed atmospheric carbon," said Dr. Steven Hallam (he/him), a microbiologist at the University of British Columbia and author of the paper published in Nature Communications Biology.

This 'biological pump' process is an important mechanism for buffering the impact of human activity on Earth's climate, said co-author Dr. Colleen Kellogg (she/her), a research scientist with the Hakai Institute. "The ocean is a huge global reservoir for atmospheric carbon dioxide. If marine heatwaves reduce the capacity for carbon dioxide to be absorbed into the ocean, then this shrinks this reservoir and leaves more of this greenhouse gas in the atmosphere."

Microbes form the base of the marine food web, performing critical functions such as synthesizing and recycling organic matter. Very little is known about how these invisible community members are affected by marine heatwaves, but understanding their responses can provide a vital sign for the rest of the marine food web.

"Marine heatwaves are one of the big challenges of climate change," explains Dr. Sachia Traving (she/her), lead author on the study at the University of Southern Denmark. "Knowing how they affect microbes -- some of the smallest but most abundant organisms on earth -- will help us understand how heatwaves will impact life in our future oceans."

To investigate these responses, the study brought together researchers from UBC, Fisheries and Oceans Canada's Institute of Ocean Sciences, and the Hakai Institute. They combined seven years of DNA sequencing and oceanographic measurements from an open-sea buoy known as Ocean Station Papa (OSP) to chart how microbial communities were structured before and during the most severe marine heatwave in recent time.

OSP is the terminal station of the Line P transect. Running continuously since 1956, Line P is one of the longest running oceanographic time series in the world, and is composed of 26 hydrographic stations originating in the coastal waters of British Columbia and heading westward to OSP, over 1,400 km from the coast.

A major impact researchers observed during the Blob, which began in 2013, was a rise in microbes specialized to survive under more nutrient limiting conditions. That shift was likely a response to changes in the composition of the region's phytoplankton, which saw a decline in larger cells that contribute to the formation of organic matter particles. That decrease in large particles in turn hinders the ocean's biological pump and ability to act as a carbon sink.

Research has shown that marine heatwaves are a direct consequence of climate change. These anomalous warm water bodies are occurring with increasing frequency as global temperatures rise, and disrupt the ecosystems in which they appear. Previous work on the Blob has documented its extensive impacts on life in the Northeastern Pacific Ocean, from phytoplankton, zooplankton and fish populations to marine mammals and birds.

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These hips don’t lie: 3D imaging of a pelvis suggests social care for saber-tooths

You can't spell 'Smilodon fatalis' without 'fatal', but researchers at La Brea Tar Pits may have found a softer side to saber-toothed cats along with a connection to our own feline and canine companions.

Published in Scientific Reports, a new study led by Dr. Mairin Balisi, Postdoctoral Fellow at La Brea Tar Pits, in collaboration with orthopaedic surgeons at Cedars-Sinai hospital, used 3D image reconstruction of external and internal bone morphology of a deformed Smilodon hip bone to reveal this saber-toothed cat suffered from hip dysplasia, suggesting a social structure that helped members survive to adulthood even when they couldn't hunt for themselves due to this birth defect.

Part of the richness of La Brea Tar Pits' collection are the fossils exhibiting signs of injury and disease-the more than 8,000 specimens that make up the pathology collection. These damaged bones are incredibly valuable for better understanding extinct animals' behavior. For instance, the lower-back trauma found (and reported in an earlier article by Dr. Balisi) in many Smilodon vertebrae points to a hunting style that includes grappling with large Ice Age prey, like bison. For more than a century, paleontologists thought the massive destruction of the pelvis examined in this study was caused by trauma or infection that eventually led to the animal's death, but a look inside the bone using modern medical technology told a different story.

Using computed tomography, the same technology common in hospitals (and veterinarian offices), the pelvis and matching thigh bone were scanned, and the resulting images were used to create 3D models of the inside of the bones. "To quote Roy Moodie in his 1930 study: this pelvis is 'the most strikingly pathological object in the collection of Rancho La Brea fossils'. And so if we were to CT-scan a specimen-with CT being a resource-intensive method- then we had to start with this one," says Dr. Balisi.

"Understanding the 3D shape of a skeleton is fascinating to me," says co-author Dr. Robert Klapper, orthopaedic surgeon and sculptor. Seeing the sheer amount of skulls on the Tar Pits' dire wolf wall over a decade ago led to talking his way into the collection. "When I saw the incredible display of bones at La Brea Tar Pits, I immediately asked to meet (then Collections Manager and study co-author) Chris Shaw. I asked him where were the abnormal joints that I knew must have existed. Chris took me to the stacks and showed me the three pelvises and one femur that he was studying. That's when we decided to collaborate and began the analysis of the etiology of the end-stage degeneration of the saber-tooth hips."

This scanned cat's CAT scan upended the previous interpretation of its hip bones. After careful analysis of the bones' internal structure, the team concluded that the damage wasn't the result of an injury suffered on the hunt, but congenital hip dysplasia.

"Computed tomography (CT) was utilized by our research group to test hypothesized etiologies of hip degeneration in the Smilodon pelvis and femur bone specimens, as it allowed us to observe the anatomical distortions at a more granular level and create three-dimensional reconstructions to use in determining how well the pathology corresponded to that typically seen in bones subjected to many years of chronic remodeling," says Dr. Abhinav Sharma, co-lead author and physician. "Additionally, from a medical standpoint, I am incredibly excited to share this study's findings because it helps illuminate the utility of 3D reconstruction for the characterization of pathology in human bone specimens and highlights its potential for use in creation of patient-specific surgical implants and prostheses tailored for each individual's unique anatomy."

Common in pet dogs and cats, the malformation of the hip bone's ball and socket joints called hip dysplasia would have been extremely problematic for Smilodon. Smilodon's impressive size meant that it needed to prey on megaherbivores like bison and camels to survive. Like living big cats, Smilodon needed strong hind limbs for speed, and from the initial leap to the subsequent grappling required to take down large prey, healthy hips would have been critical to their hunting strategy.

"In this case, our animal sustained a developmental condition (not an injury) and was able to live to adulthood-suggesting that it must have received support, perhaps by food-sharing with its family," says Dr. Balisi.

Hobbled since it was a kitten, this individual could never have hunted or defended territory on its own. While a beloved Labrador retriever might receive a hip replacement or careful pampering by human owners, a Smilodon would have been left to nature -- and their saber-toothed family. This big cat's survival to adulthood suggests that saber-toothed cats took care of one another.

"Social behavior is difficult to infer in fossils. Smilodon in particular is only distantly related to big cats today (like the distance between our house-cats and the African lion, if not greater)," says Dr. Balisi. "So we can't reconstruct Smilodon's socialitybased on, say, living lions and tigers. Living big cats range in social structure anyway: the lion is the only one that's truly social, while tigers and jaguars tend to be solitary or even vary in sociality within a single species."

"In Smilodon's case, we are lucky to have multiple lines of evidence-a lot of them from La Brea Tar Pits-suggesting that it was social," Dr. Balisi says. "Thousands of individuals are preserved here, which is more likely if Smilodon had been social than solitary." This isn't the first sign of saber-tooth social behavior. In other Smilodon fossils, researchers have found signs of healing from grievous injuries that likely would've meant starving without support. Dr. Balisi adds, "evidence from tooth and bone development also support Smilodon having had delayed weaning and extended family care-not just from here but also from other asphalt seeps globally, like Corralito in Ecuador."

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Cleveland Clinic study links gut microbiome and aggressive prostate cancer

Cleveland Clinic researchers have shown for the first time that diet-associated molecules in the gut are associated with aggressive prostate cancer, suggesting dietary interventions may help reduce risk. Findings from the study were published in Cancer Epidemiology, Biomarkers & Prevention.

While more research will be necessary, the study's lead author Nima Sharifi, M.D., says findings from the team's analysis of nearly 700 patients may have clinical implications for diagnosing and preventing lethal prostate cancer.

"We found that men with higher levels of certain diet-related molecules are more likely to develop aggressive prostate cancer," said Dr. Sharifi, director of Cleveland Clinic's Genitourinary Malignancies Research Center. "As we continue our research in this area, our hope is that one day these molecules can be used as early biomarkers of prostate cancer and help identify patients who can modify their disease risk by making dietary and lifestyle changes."

In this study, Dr. Sharifi and his collaborators -- including Stanley Hazen, M.D., Ph.D., and Eric Klein, M.D. -- analyzed data from patients previously enrolled in the National Cancer Institute's Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial.

They studied baseline levels of certain dietary nutrients and metabolites (byproducts produced when a substance is broken down in the gut) found in patients' blood serum prior to prostate cancer diagnosis. They compared serum levels between healthy patients and those who later received a prostate cancer diagnosis and died from the disease.

The researchers found that men with elevated levels of a metabolite called phenylacetylglutamine (PAGln) were approximately two or three times more likely to be diagnosed with lethal prostate cancer. This metabolite is produced when microbes in the gut break down phenylalanine, an amino acid found in many plant- and animal-based protein sources like meat, beans and soy.

In addition to PAGln, researchers also discovered that elevated levels of two nutrients abundant in animal products, including red meat, egg yolks and high-fat dairy products, called choline and betaine, also were linked with increased risk for aggressive prostate cancer.

While these nutrients and gut metabolites have been studied previously in heart disease and stroke, this is the first time that gut microbiome metabolites have been studied clinically in relation to prostate cancer outcomes.

Dr. Hazen was the first to identify PAGln's association with increased cardiovascular disease risk. The findings were published in 2020 in Cell. "Interestingly, we found that PAGln binds to the same receptors as beta blockers, which are drugs commonly prescribed to help lower blood pressure and subsequent risk of cardiac events," said Dr. Hazen, director of Cleveland Clinic's Center for Microbiome & Human Health and chair of Lerner Research Institute's Department of Cardiovascular & Metabolic Sciences. "This suggests that part of beta blockers' potent efficacy may be due to blocking the metabolite's activity."

"New insights are emerging from large-scale clinical datasets that show use of beta blockers is also associated with lower mortality due to prostate cancer," said Dr. Sharifi, who is a staff physician in Lerner Research Institute's Department of Cancer Biology. "We will continue to work together to investigate the possible mechanisms linking PAGln activity and prostate cancer disease processes in hopes of identifying new therapeutic targets for our patients."

The research team also will continue to explore the reliability of using choline, betaine and PAGln as biomarkers of aggressive prostate cancer and how dietary interventions can be used to modulate their levels and reduce patients' subsequent disease risk.

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What big teeth you have: Tooth root surface area can determine primate size

An often overlooked feature could give scientists new insight into the lives of ancient primate species. Researchers from North Carolina State University have developed formulas that can calculate the body size of a primate based on the root size of its teeth. The formulas could allow researchers to make use of partial and incomplete fossils in order to learn how ancient primates -- including human ancestors -- interacted with their environment.

Ashley Deutsch, NC State graduate student and first author of a paper describing the research, wanted to know if it was possible to determine what a primate's diet was without having the actual tooth crowns at hand -- by looking instead at the roots.

What we commonly think of when we think of teeth isn't the whole story -- the part that does the chewing is merely the crown. The part that keeps the tooth anchored in the jaw is the root.

"The tooth root transmits the force of the jaws into the food," says Adam Hartstone-Rose, professor of biological sciences at NC State and paper coauthor. "You can think of the root as the handle of a hammer -- the handle size is related to the amount of force you can put into the hammer. So if a hammer has a small handle, it will have a small head to hammer small things. In the same way, a big tooth root can transmit more force to the tooth's crown to crush more obdurate foods."

Deutsch and the research team initially set out to determine whether tooth roots could indicate the shape of the tooth's crown, thus telling them what particular primates preferred to eat. Using computer tomography, Deutsch analyzed and calculated the tooth root surface area -- or area of contact where the root fits into the jaw -- of 70 primates from 75 species, ranging in size from tiny mouse lemurs to great apes.

"It was a bit like trying to figure out if you have an axe or hammer based on the shape of the handle," Deutsch says.

Ultimately, she found that the tooth roots only related to diet in a few lineages (for example, lemurs); however, she was able to determine how big the primates were across all lineages.

Deutsch developed a series of formulas based on the relationship between the tooth root surface of a molar or premolar -- the teeth located between canines and molars -- and primate body mass. The formulas can be used to estimate body mass of primates with more or less specificity, depending upon whether their class is known. The formulas can also explain up to 96% of variation in body mass within the examined primate sample.

But perhaps the most useful application of the equation will be with fossils that are currently of little use to anthropologists and paleontologists.

"As long as the fossil has a bit of root you can use the formulas even if the tooth crowns are missing," Deutsch says. "Fossils are often maddeningly incomplete, but now those incomplete pieces can be useful, and they could answer questions about our own lineage, like how big our ancient ancestors were."

Deutsch hopes to continue refining the existing equations and expand the work beyond primates to other mammals, including carnivores.

"Ashley has looked at something that is often preserved but also generally ignored by science and found it might hold answers to one of the most important ecological questions," Hartstone-Rose says. "Just knowing how big an animal is tells you a lot about how it interacted with the environment. And that could give us a lot of insight into our own ancient history."

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Astronomers may have discovered a planet outside of our galaxy

Signs of a planet transiting a star outside of the Milky Way galaxy may have been detected for the first time. This intriguing result, using NASA's Chandra X-ray Observatory, opens up a new window to search for exoplanets at greater distances than ever before.

The possible exoplanet candidate is located in the spiral galaxy Messier 51 (M51), also called the Whirlpool Galaxy because of its distinctive profile.

Exoplanets are defined as planets outside of our Solar System. Until now, astronomers have found all other known exoplanets and exoplanet candidates in the Milky Way galaxy, almost all of them less than about 3,000 light-years from Earth. An exoplanet in M51 would be about 28 million light-years away, meaning it would be thousands of times farther away than those in the Milky Way.

"We are trying to open up a whole new arena for finding other worlds by searching for planet candidates at X-ray wavelengths, a strategy that makes it possible to discover them in other galaxies," said Rosanne Di Stefano of the Center for Astrophysics | Harvard & Smithsonian (CfA) in Cambridge, Massachusetts, who led the study, which was published in Nature Astronomy.

This new result is based on transits, events in which the passage of a planet in front of a star blocks some of the star's light and produces a characteristic dip. Astronomers using both ground-based and space-based telescopes -- like those on NASA's Kepler and TESS missions -- have searched for dips in optical light, electromagnetic radiation humans can see, enabling the discovery of thousands of planets.

Di Stefano and colleagues have instead searched for dips in the brightness of X-rays received from X-ray bright binaries. These luminous systems typically contain a neutron star or black hole pulling in gas from a closely orbiting companion star. The material near the neutron star or black hole becomes superheated and glows in X-rays.

Because the region producing bright X-rays is small, a planet passing in front of it could block most or all of the X-rays, making the transit easier to spot because the X-rays can completely disappear. This could allow exoplanets to be detected at much greater distances than current optical light transit studies, which must be able to detect tiny decreases in light because the planet only blocks a tiny fraction of the star.

The team used this method to detect the exoplanet candidate in a binary system called M51-ULS-1, located in M51. This binary system contains a black hole or neutron star orbiting a companion star with a mass about 20 times that of the Sun. The X-ray transit they found using Chandra data lasted about three hours, during which the X-ray emission decreased to zero. Based on this and other information, the researchers estimate the exoplanet candidate in M51-ULS-1 would be roughly the size of Saturn, and orbit the neutron star or black hole at about twice the distance of Saturn from the Sun.

While this is a tantalizing study, more data would be needed to verify the interpretation as an extragalactic exoplanet. One challenge is that the planet candidate's large orbit means it would not cross in front of its binary partner again for about 70 years, thwarting any attempts for a confirming observation for decades.

"Unfortunately to confirm that we're seeing a planet we would likely have to wait decades to see another transit," said co-author Nia Imara of the University of California at Santa Cruz. "And because of the uncertainties about how long it takes to orbit, we wouldn't know exactly when to look."

Can the dimming have been caused by a cloud of gas and dust passing in front of the X-ray source? The researchers consider this to be an unlikely explanation, as the characteristics of the event observed in M51-ULS-1 are not consistent with the passage of such a cloud. The model of a planet candidate is, however, consistent with the data.

"We know we are making an exciting and bold claim so we expect that other astronomers will look at it very carefully," said co-author Julia Berndtsson of Princeton University in New Jersey. "We think we have a strong argument, and this process is how science works."

If a planet exists in this system, it likely had a tumultuous history and violent past. An exoplanet in the system would have had to survive a supernova explosion that created the neutron star or black hole. The future may also be dangerous. At some point the companion star could also explode as a supernova and blast the planet once again with extremely high levels of radiation.

Di Stefano and her colleagues looked for X-ray transits in three galaxies beyond the Milky Way galaxy, using both Chandra and the European Space Agency's XMM-Newton. Their search covered 55 systems in M51, 64 systems in Messier 101 (the "Pinwheel" galaxy), and 119 systems in Messier 104 (the "Sombrero" galaxy), resulting in the single exoplanet candidate described here.

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Advancing agriculture threatens the livelihoods of forest-dependent people

There are few places on the globe where tropical forests are disappearing as rapidly as in the South American Gran Chaco. This semiarid lowland covers over a million km2 and stretches across parts of Paraguay, Bolivia, Argentina, and Brazil. While it's known that agricultural expansion into tropical forests leads to major environmental destruction, the social impacts of deforestation often remain hidden. A main reason for this is a lack of data on where people live inside tropical forests.

A new study, published this week in the Proceedings of the National Academy of Sciences and involving an international team of researchers from Germany, Argentina, and the Netherlands, as well as from McGill University, puts these forest-dependent people on the map for the first time. By systematically using high-resolution satellite images, the team digitized individual homesteads of forest-dependent people across the Chaco and found that close to 20 per cent of these homesteads had disappeared over the period between 1985-2015.

The effects of expanding agribusiness

"We found that in 1985 there were about 28,000 homesteads spread across almost half of the Chaco forests," says Dr. Christian Levers, Assistant Professor at VU Amsterdam and lead-author of the study. "By looking at images from the past 30 years we found that more than 5,000 homesteads have disappeared since then. And an even larger number of homesteads have lost the forests on which they depend due to encroaching agribusiness."

Forest-dependent people use the forests surrounding their homesteads for firewood and timber, livestock grazing, subsistence hunting, or collecting honey. But homestead numbers have been dropping as advancing agribusiness reduces the size of the forests on which they depend, and large-scale farmers erect fences that limit people's access to the forests that remain standing.

"Mapping where forest-dependent people live and how deforestation affects them is a first and much-needed step towards more adequately representing them in land-use planning and policy discussions," says Yann le Polain de Waroux, one of the study's co-authors and an Assistant Professor of Geography at McGill University.

Global consumption patterns

Deforestation in the Gran Chaco is related mainly to beef and soybean production for international markets, including those in Europe and North America. The study found that the homesteads that disappeared were mainly located where agribusiness has expanded most dramatically.

"This research clearly shows how our consumption impacts forest-dependent people around the world, people who are vulnerable and poor," says Dr. Alfredo Romero-Muñoz, a researcher at Humboldt University Berlin and co-author of the study. "Agriculture is expanding into many tropical dry forests around the world, and we urgently need to consider not only the impacts on biodiversity and the global climate, but also the huge impacts it has on forest-dependent people."

A key finding of the study is that deforestation leads to the increasing ecological marginalization of forest-dependent people. "What we mean here is that local people experience a massive erosion of the basis of their livelihoods as the forest is converted," explains Prof. Tobias Kuemmerle from Humboldt-University Berlin and a senior author on the study. "We also found that those homesteads that persist or have emerged are often in places that are not very suitable for agriculture, which is another form of marginalization."

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Enhanced touch screens could help you 'feel' objects

The next time you buy a new couch, you may not ever have to leave your old one to get a feel for the texture of the new material.

Dr. Cynthia Hipwell, Oscar S. Wyatt Jr. '45 Chair II Professor in the J. Mike Walker '66 Department of Mechanical Engineering at Texas A&M University, is leading a team working to better define how the finger interacts with a device with the hope of aiding in the further development of technology that goes beyond sensing and reacting to your touch.

The team's research was recently published and featured on the cover of the journal Advanced Materials.

The ultimate goal of furthering this human-machine interface is to give touch devices the ability to provide users with a richer touch-based experience by equipping the technology with the ability to mimic the feeling of physical objects. Hipwell shared examples of potential implementations ranging from a more immersive virtual reality platform to tactile display interfaces like those in a motor vehicle dashboard and a virtual shopping experience that would let the user feel the texture of materials before purchasing them.

"This could allow you to actually feel textures, buttons, slides and knobs on the screen," Hipwell said. "It can be used for interactive touch screen-based displays, but one holy grail would certainly be being able to bring touch into shopping so that you could feel the texture of fabrics and other products while you're shopping online."

Hipwell explained that at its essence, the "touch" in current touch screen technology is more for the screen's benefit than the user. With the emergence and refinement of increasingly sophisticated haptic technology, that relationship between user and device can grow to be more reciprocal.

She added that the addition of touch as a sensory input would ultimately enrich virtual environments and lighten the burden of communication currently carried by audio and visuals.

"When we look at virtual experiences, they're primarily audio and visual right now and we can get audio and visual overload," Hipwell said. "Being able to bring touch into the human-machine interface can bring a lot more capability, much more realism, and it can reduce that overload. Haptic effects can be used to draw your attention to make something easier to find or easier to do using a lower cognitive load."

Hipwell and her team are approaching the research by looking at the multiphysics -- the coupled processes or systems involving multiple physical fields occurring at the same time -- of the interface between the user's finger and the device. This interface is incredibly complex and changes with different users and environmental conditions.

"We're looking at electro-wetting effects (the forces that result from an applied electric field), electrostatic effects, changes in properties of the finger, the material properties and surface geometry of the device, the contact mechanics, the fluid motion, charge transport -- really, everything that's going on in the interface to understand how the device can be designed to be more reliable and higher performing," Hipwell said. "Ultimately, our goal is to create predictive models than enable a designer to create devices with maximum haptic effect and minimum sensitivity to user and environmental variation."

As research into and development of the technology continues to progress, Hipwell said she predicts consumers will begin to see early elements implemented into common devices over the next few years, with some early products already in development.

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Potentially harmful industrial chemicals detected in US fast foods

Chicken nuggets, burritos and other popular items consumers buy from fast food outlets in the United States contain chemicals that are linked to a long list of serious health problems, according to a first-of-its-kind study published today.

Researchers at the George Washington University and their colleagues bought fast foods from popular outlets and found 10 of 11 potentially harmful chemicals in the samples, including phthalates, a group of chemicals that are used to make plastics soft and are known to disrupt the endocrine system. The research team also found other plasticizers, chemicals that are emerging as replacements to phthalates.

"We found phthalates and other plasticizers are widespread in prepared foods available at U.S. fast food chains, a finding that means many consumers are getting a side of potentially unhealthy chemicals along with their meal," Lariah Edwards, lead author of the study and a postdoctoral scientist at GW, said. "Stronger regulations are needed to help keep these harmful chemicals out of the food supply."

Previously, a GW research team led by Ami Zota, a professor of environmental and occupational health, looked at fast food consumption in a national survey and found people who reported eating more fast foods had higher levels of phthalates. No one has looked at the link between fast food and non-phthalate plasticizers, which are used in place of banned or restricted phthalates in food packaging and processing equipment.

In this study, Edwards, Zota and their colleagues purchased 64 fast food items from different restaurants and asked for three pairs of unused food handling gloves. The team tested food items and the gloves for 11 kinds of phthalates and plasticizers, finding that:
 

• 81% of the food samples studied contained a phthalate called DnBP and 70% contained DEHP. Both these chemicals have been linked in numerous studies to fertility and reproductive problems in humans. These phthalates can also increase risk for learning, attention, and behavioral disorders in childhood.
• 86% of the foods contained the replacement plasticizer known as DEHT, a chemical that needs further study to determine its impact on human health.
• Foods containing meats, such as cheeseburgers and chicken burritos, had higher levels of the chemicals studied.
• Chicken burritos and cheeseburgers had the highest levels of DEHT. The researchers noted that food handling gloves collected from the same restaurants also contained this chemical.
• Cheese pizzas had the lowest levels of most chemicals tested.

Phthalates and replacement plasticizers are chemicals used to make plastics soft and can migrate out of plastics into the food, which is ingested. Some sources of plastics include food handling gloves, industrial tubing, food conveyor belts and the outer packaging used to wrap fast food meals available in restaurants.

Previous research by Zota's team suggests that people who eat food cooked at home have lower levels of these chemicals in their bodies, probably because home cooks do not use food handling gloves or plastic packaging. To avoid these industrial chemicals, consumers can switch to mostly home cooked meals, which are often healthier than fast food, Edwards said.

Both Edwards and Zota say their study suggests the need for greater scrutiny and regulation of chemicals used to make food. They point out that replacement plasticizers are increasingly used to replace banned or restricted phthalates yet the studies needed to show that they are safe have yet to be done.

The study also raises the concern that certain racial/minority groups may be disproportionately affected by these chemicals.

"Disadvantaged neighborhoods often have plenty of fast food outlets, but limited access to healthier foods like fruits and vegetables," Zota said. "Additional research needs to be done to find out whether people living in such food deserts are at higher risk of exposure to these harmful chemicals."

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Neutron star collisions are 'goldmine' of heavy elements, study finds

Most elements lighter than iron are forged in the cores of stars. A star's white-hot center fuels the fusion of protons, squeezing them together to build progressively heavier elements. But beyond iron, scientists have puzzled over what could give rise to gold, platinum, and the rest of the universe's heavy elements, whose formation requires more energy than a star can muster.

A new study by researchers at MIT and the University of New Hampshire finds that of two long-suspected sources of heavy metals, one is more of a goldmine than the other.

The study, published today in Astrophysical Journal Letters, reports that in the last 2.5 billion years, more heavy metals were produced in binary neutron star mergers, or collisions between two neutron stars, than in mergers between a neutron star and a black hole.

The study is the first to compare the two merger types in terms of their heavy metal output, and suggests that binary neutron stars are a likely cosmic source for the gold, platinum, and other heavy metals we see today. The findings could also help scientists determine the rate at which heavy metals are produced across the universe.

"What we find exciting about our result is that to some level of confidence we can say binary neutron stars are probably more of a goldmine than neutron star-black hole mergers," says lead author Hsin-Yu Chen, a postdoc in MIT's Kavli Institute for Astrophysics and Space Research.

Chen's co-authors are Salvatore Vitale, assistant professor of physics at MIT, and Francois Foucart of UNH.

An efficient flash

As stars undergo nuclear fusion, they require energy to fuse protons to form heavier elements. Stars are efficient in churning out lighter elements, from hydrogen to iron. Fusing more than the 26 protons in iron, however, becomes energetically inefficient.

"If you want to go past iron and build heavier elements like gold and platinum, you need some other way to throw protons together," Vitale says.

Scientists have suspected supernovae might be an answer. When a massive star collapses in a supernova, the iron at its center could conceivably combine with lighter elements in the extreme fallout to generate heavier elements.

In 2017, however, a promising candidate was confirmed, in the form a binary neutron star merger, detected for the first time by LIGO and Virgo, the gravitational-wave observatories in the United States and in Italy, respectively. The detectors picked up gravitational waves, or ripples through space-time, that originated 130 million light years from Earth, from a collision between two neutron stars -- collapsed cores of massive stars, that are packed with neutrons and are among the densest objects in the universe.

The cosmic merger emitted a flash of light, which contained signatures of heavy metals.

"The magnitude of gold produced in the merger was equivalent to several times the mass of the Earth," Chen says. "That entirely changed the picture. The math showed that binary neutron stars were a more efficient way to create heavy elements, compared to supernovae."

A binary goldmine

Chen and her colleagues wondered: How might neutron star mergers compare to collisions between a neutron star and a black hole? This is another merger type that has been detected by LIGO and Virgo and could potentially be a heavy metal factory. Under certain conditions, scientists suspect, a black hole could disrupt a neutron star such that it would spark and spew heavy metals before the black hole completely swallowed the star.

The team set out to determine the amount of gold and other heavy metals each type of merger could typically produce. For their analysis, they focused on LIGO and Virgo's detections to date of two binary neutron star mergers and two neutron star -- black hole mergers.

The researchers first estimated the mass of each object in each merger, as well as the rotational speed of each black hole, reasoning that if a black hole is too massive or slow, it would swallow a neutron star before it had a chance to produce heavy elements. They also determined each neutron star's resistance to being disrupted. The more resistant a star, the less likely it is to churn out heavy elements. They also estimated how often one merger occurs compared to the other, based on observations by LIGO, Virgo, and other observatories.

Finally, the team used numerical simulations developed by Foucart, to calculate the average amount of gold and other heavy metals each merger would produce, given varying combinations of the objects' mass, rotation, degree of disruption, and rate of occurrence.

On average, the researchers found that binary neutron star mergers could generate two to 100 times more heavy metals than mergers between neutron stars and black holes. The four mergers on which they based their analysis are estimated to have occurred within the last 2.5 billion years. They conclude then, that during this period, at least, more heavy elements were produced by binary neutron star mergers than by collisions between neutron stars and black holes.

The scales could tip in favor of neutron star-black hole mergers if the black holes had high spins, and low masses. However, scientists have not yet observed these kinds of black holes in the two mergers detected to date.

Chen and her colleagues hope that, as LIGO and Virgo resume observations next year, more detections will improve the team's estimates for the rate at which each merger produces heavy elements. These rates, in turn, may help scientists determine the age of distant galaxies, based on the abundance of their various elements.

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Fungal outbreak in marine mammals began on land

In the early 2000s, a fungus infected hundreds of animals and people in British Columbia and Washington State. Scientists found that the disease also killed porpoises and dolphins in the Salish Sea-perhaps affecting cetaceans even earlier than people.

A study published today in Diseases of Aquatic Organisms explores how human-caused changes on land can affect aquatic animals, specifically in the case of the fungal pathogen, Cryptococcus gattii. Led by the University of California, Davis, a team of scientists from Canada and the Pacific Northwest pieced together the history of the fungal outbreak in marine mammals. They assembled and analyzed data collected over decades by veterinarians, microbiologists, marine mammal biologists, and marine mammal stranding responders.

C. gattii can cause lung and brain disease. It lives in soil and in tree dwellings and is acquired by breathing in fungal spores. It is not considered contagious between individuals. Typically found in tropical and subtropical forests paralleling the distribution of eucalyptus trees, C. gattii was likely translocated to the Pacific Northwest in the early 1900's, although the exact mechanisms are unknown.

Beginning in 1999 on Vancouver Island, humans, domestic animals, and terrestrial wildlife became infected with C. gattii, progressively affecting individuals living on mainland British Columbia, Washington, Oregon, and California. The researchers found that 42 dolphins and porpoises in the Salish Sea also died from the fungal pathogen, including harbor porpoises, Dall's porpoises, and Pacific white-side dolphins.

Construction, deforestation, and other activities that disturb soil can aerosolize C. gattii spores, causing infection in people and animals that live near the disturbed sites and breathe in the spores.

"As we change the environment in unprecedented ways, we could see more diseases that affect people and wildlife," said lead author Sarah Teman, a research assistant at the SeaDoc Society, a program of the Karen C. Drayer Wildlife Health Center at the UC Davis School of Veterinary Medicine.

The marine mammals that died from C. gattii were found near terrestrial hotspots, suggesting that the spores settled on the surface of the sea, where the porpoises and dolphins inhaled them when they surfaced to breathe.

Researchers also found evidence that the first probable case of C. gattii in the Pacific Northwest could have occurred in a Dall's porpoise in 1997 -- two years before the identification of the first human case in the region in 1999.

"Often we study marine mammals because they play important roles in the ecosystem, and they are cool," said Joe Gaydos, UC Davis wildlife veterinarian at SeaDoc Society and co-investigator. "Too often we forget that they can also alert us to diseases that affect humans."

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Traces of an ancient road in a lake

Anyone traveling from the German city of Brandenburg via Berlin to Frankfurt an der Oder at the Polish-German border does so along an ancient route that reaches far into Poland. German and Polish researchers have now documented the influence of this East-West connection on the history of the landscape by examining the sediments of Lake Czechowskie in the Bory Tucholskie and also evaluating historical sources. According to the results, three phases of landscape development can be distinguished in the last eight hundred years: from an almost untouched landscape through an intermediate phase lasting several centuries -- characterized by alternations between strong settlement activity and the return of nature after wars -- to today's cultural landscape.

One of the two main authors, Achim Brauer of the GFZ German Research Centre for Geosciences in Potsdam, says: "Wars had a clear influence, as the Via Marchionis was repeatedly used for troop transports that led to local destruction and devastation. In this study, for the first time, we have shown the impact on the landscape for every war in the region's history. In general, wars have led to greater or lesser devastation ('renaturalization') of the landscape, which has also lasted for varying lengths of time."

At other times, it was political developments that left their mark on the landscape, such as an agrarian reform in 1343, which led, with a certain time lag, to an accelerated "anthropogenization" of the landscape, that is, to clearly visible human influence. In the sediments of Lake Czechowskie this is shown by a strong increase of rye pollen and the decrease of birch and pine pollen.

Because sediments in a lake exhibit annual stratification similar to tree rings, the German-Polish team was able to pinpoint the year from which pollen originated by counting the individual layers ("warves") down to a resolution of five years. According to this, the landscape remained largely untouched by humans until about 1350 AD. Extensive forests and natural grasses dominated. Then followed five turbulent centuries. The expansion of agriculture and the formation of larger towns were favored by a warm climate and politically calm times. However, between 1409 and 1435 there was war between the Teutonic Order and Poland -- fields became fallow land, forests expanded again. After peace was concluded, five quiet decades followed again, during which an increase in handicrafts was also evident. Hardwood was cut to obtain building material and potash -- thus, birch pollen disappeared from lake sediments, rye again increased massively.

Huge army campaigns with thousands of riders and foot soldiers, plague epidemics in several waves and some very cold years with crop failures are also documented. Then, from the middle of the 19th century, the influence of agriculture, settlements and economic activity took over to such an extent that one can speak of a predominantly human influence, which continues to this day.

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That primate’s got rhythm!

Songbirds share the human sense of rhythm, but it is a rare trait in non-human mammals. An international research team led by senior investigators Marco Gamba from the University of Turin and MPI’s Andrea Ravignani set out to look for musical abilities in primates. “There is longstanding interest in understanding how human musicality evolved, but musicality is not restricted to humans”, says Ravignani. “Looking for musical features in other species allows us to build an ‘evolutionary tree’ of musical traits, and understand how rhythm capacities originated and evolved in humans.”

To find out whether non-human mammals have a sense of rhythm, the team decided to study one of the few ‘singing’ primates, the critically endangered lemur Indri indri. The researchers wanted to know whether indri songs have categorical rhythm, a ‘rhythmic universal’ found across human musical cultures. Rhythm is categorical when intervals between sounds have exactly the same duration (1:1 rhythm) or doubled duration (1:2 rhythm). This type of rhythm makes a song easily recognisable, even if it is sung at different speeds. Would indri songs show this “uniquely human” rhythm?

Ritardando in the rainforest

Over a period of twelve years, the researchers from Turin visited the rainforest of Madagascar to collaborate with a local primate study group. The investigators recorded songs from twenty indri groups (39 animals), living in their natural habitat. Members of an indri family group tend to sing together, in harmonised duets and choruses. The team found that indri songs had the classic rhythmic categories (both 1:1 and 1:2), as well as the typical ‘ritardando’ or slowing down found in several musical traditions. Male and female songs had a different tempo but showed the same rhythm.

According to first author Chiara de Gregorio and her colleagues, this is the first evidence of a ‘rhythmic universal’ in a non-human mammal. But why should another primate produce categorical ‘music-like’ rhythms? The ability may have evolved independently among ‘singing’ species, as the last common ancestor between humans and indri lived 77.5 million years ago. Rhythm may make it easier to produce and process songs, or even to learn them.

Endangered species

“Categorical rhythms are just one of the six universals that have been identified so far”, explains Ravignani. “We would like to look for evidence of others, including an underlying ‘repetitive’ beat and a hierarchical organisation of beats—in indri and other species.” The authors encourage other researchers to gather data on indri and other endangered species, “before it is too late to witness their breath-taking singing displays.”

From Science Daily

Men, women ride the same emotional roller coaster

Contrary to widely held gender stereotypes, women are not more emotional than men, researchers say.

Feelings such as enthusiasm, nervousness or strength are often interpreted differently between the two genders. It's what being "emotional" means to men vs. women that is part of a new University of Michigan study that dispels these biases.

For instance, a man whose emotions fluctuate during a sporting event is described as "passionate." But a woman whose emotions change due to any event, even if provoked, is considered "irrational," says the study's senior author Adriene Beltz, U-M assistant professor of psychology.

Beltz and colleagues Alexander Weigard, U-M assistant professor of psychiatry, and Amy Loviska, a graduate student at Purdue University, followed 142 men and women over 75 days to learn more about their daily emotions, both positive and negative. The women were divided into four groups: one naturally cycling and three others using different forms of oral contraceptives.

The researchers detected fluctuations in emotions three different ways, and then compared the sexes. They found little-to-no differences between the men and the various groups of women, suggesting that men's emotions fluctuate to the same extent as women's do (although likely for different reasons).

"We also didn't find meaningful differences between the groups of women, making clear that emotional highs and lows are due to many influences -- not only hormones," she said.

The findings have implications beyond everyday people, the researchers say. Women have historically been excluded from research participation in part due to the assumption that ovarian hormone fluctuations lead to variation, especially in emotion, that can't be experimentally controlled, they say.

"Our study uniquely provides psychological data to show that the justifications for excluding women in the first place (because fluctuating ovarian hormones, and consequently emotions, confounded experiments) were misguided," Beltz said.

From Science Daily

Infant planet discovered

One of the youngest planets ever found around a distant infant star has been discovered by an international team of scientists led by University of Hawaii at Manoa faculty, students, and alumni.

Thousands of planets have been discovered around other stars, but what sets this one apart is that it is newly-formed and can be directly observed. The planet, named 2M0437b, joins a handful of objects advancing our understanding of how planets form and change with time, helping shed new light on the origin of the Solar System and Earth. The in-depth research was recently published in Monthly Notices of the Royal Astronomical Society.

"This serendipitous discovery adds to an elite list of planets that we can directly observe with our telescopes," explained lead author Eric Gaidos, a professor in the UH Manoa Department of Earth Sciences. "By analyzing the light from this planet we can say something about its composition, and perhaps where and how it formed in a long-vanished disk of gas and dust around its host star."

The researchers estimate that the planet is a few times more massive than Jupiter, and that it formed with its star several million years ago, around the time the main Hawaiian Islands first emerged above the ocean. The planet is so young that it is still hot from the energy released during its formation, with a temperature similar to the lava erupting from Kilauea Volcano.

Key Maunakea telescopes

In 2018, 2M0437b was first seen with the Subaru Telescope on Maunakea by UH Institute for Astronomy (IfA) visiting researcher Teruyuki Hirano. For the past several years, it has been studied carefully utilizing other telescopes on the mauna.

Gaidos and his collaborators used the Keck Observatory on Maunakea to monitor the position of the host star as it moved across the sky, confirming that planet 2M0437b was truly a companion to the star, and not a more distant object. The observations required three years because the star moves slowly across the sky.

The planet and its parent star lie in a stellar "nursery" called the Taurus Cloud. 2M0437b is on a much wider orbit than the planets in the Solar System; its current separation is about one hundred times the Earth-Sun distance, making it easier to observe. However, sophisticated "adaptive" optics are still needed to compensate for the image distortion caused by Earth's atmosphere.

"Two of the world's largest telescopes, adaptive optics technology and Maunakea's clear skies were all needed to make this discovery," said co-author Michael Liu, an astronomer at IfA. "We are all looking forward to more such discoveries, and more detailed studies of such planets with the technologies and telescopes of the future."

Future research potential

Gathering more in-depth research about the newly-discovered planet may not be too far away. "Observations with space telescopes such as NASA's Hubble and the soon-to-be-launched James Webb Space Telescope could identify gases in its atmosphere and reveal whether the planet has a moon-forming disk," Gaidos added.

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A new Earth bombardment model

A team led by Southwest Research Institute has updated its asteroid bombardment model of the Earth with the latest geologic evidence of ancient, large collisions. These models have been used to understand how impacts may have affected oxygen levels in the Earth's atmosphere in the Archean eon, 2.5 to 4 billion years ago.

When large asteroids or comets struck early Earth, the energy released melted and vaporized rocky materials in the Earth's crust. The small droplets of molten rock in the impact plume would condense, solidify and fall back to Earth, creating round, globally distributed sand-size particles. Known as impact spherules, these glassy particles populated multiple thin, discrete layers in the Earth's crust, ranging in age from about 2.4 to 3.5 billion years old. These Archean spherule layers are markers of ancient collisions. "In recent years, a number of new spherule layers have been identified in drill cores and outcrops, increasing the total number of known impact events during the early Earth," said Dr. Nadja Drabon, a professor at Harvard University and a co-author of the paper.

"Current bombardment models underestimate the number of late Archean spherule layers, suggesting that the impactor flux at that time was up to 10 times higher than previously thought," said SwRI's Dr. Simone Marchi, lead author of a paper about this research in Nature Geoscience. "What's more, we find that the cumulative impactor mass delivered to the early Earth was an important 'sink' of oxygen, suggesting that early bombardment could have delayed oxidation of Earth's atmosphere."

The abundance of oxygen in Earth's atmosphere is due to a balance of production and removal processes. These new findings correspond to the geological record, which shows that oxygen levels in the atmosphere varied but stayed relatively low in the early Archean eon. Impacts by bodies larger than six miles (10 km) in diameter may have contributed to its scarcity, as limited oxygen present in the atmosphere of early Earth would have been chemically consumed by impact vapors, further reducing its abundance in the atmosphere.

"Late Archean bombardment by objects over six miles in diameter would have produced enough reactive gases to completely consume low levels of atmospheric oxygen," said Dr. Laura Schaefer, a professor at Stanford University and a co-author of the paper. "This pattern was consistent with evidence for so-called 'whiffs' of oxygen, relatively steep but transient increases in atmospheric oxygen that occurred around 2.5 billion years ago. We think that the whiffs were broken up by impacts that removed the oxygen from the atmosphere. This is consistent with large impacts recorded by spherule layers in Australia's Bee Gorge and Dales Gorge."

SwRI's results indicate that the Earth was subject to substantial numbers of large impacts throughout the late Archean era. Around 2.4 billion years ago, during the tail end of this bombardment, the Earth went through a major shift in surface chemistry triggered by the rise of atmospheric oxygen, dubbed the Great Oxidation Event (GOE), which is attributed to changes in the oxygen production-sink balance. Among the proposed scenarios are a presumed increase in oxygen production and decrease in gases capable of removing oxygen, either from volcanic sources or through their gradual loss to space.

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‘Raptor-like’ dinosaur discovered in Australian mine, actually uncovered as a timid vegetarian

Fossil footprints found in an Australian coal mine around 50 years ago have long been thought to be that of a large 'raptor-like' predatory dinosaur, but scientists have in fact discovered they were instead left by a timid long-necked herbivore.

University of Queensland palaeontologist Dr Anthony Romilio recently led an international team to re-analyse the footprints, dated to the latter part of the Triassic Period, around 220 million-year-ago.

"For years it's been believed that these tracks were made by a massive theropod predator that was part of the dinosaur family Eubrontes, with legs over two metres tall," Dr Romilio said.

"This idea caused a sensation decades ago because no other meat-eating dinosaur in the world approached that size during the Triassic period."

However, findings made by a team of international researchers, published today in the peer-reviewed journal Historical Biology, in fact shows the tracks were instead made by a dinosaur known as a Prosauropod - a vegetarian dinosaur that were smaller, with legs about 1.4 metres tall and a body length of six metres.

The research team suspected there was something not-quite-right with the original size estimates and there was a good reason for their doubts.

"Unfortunately, most earlier researchers could not directly access the footprint specimen for their study, instead relying on old drawings and photographs that lacked detail," Dr Romilio said.

The dinosaur fossils were discovered more than half a century ago around 200 metres deep underground at an Ipswich coal mine, just west of Brisbane.

"It must have been quite a sight for the first miners in the 1960s to see big bird-like footprints jutting down from the ceiling," Dr Romilio said.

Hendrik Klein, co-author and fossil expert from Saurierwelt Paläontologisches Museum in Germany, said the footprints -- referred to as 'Evazoum', scientifically, the footprint type made by prosauropod dinosaurs -- were made on the water-sodden layers of ancient plant debris with the tracks later in-filled by silt and sand.

"This explains why today they occur in an upside-down position right above our heads," Mr Klein said.

"After millions of years, the plant material turned into coal which was extracted by the miners to reveal a ceiling of siltstone and sandstone, complete with the natural casts of dinosaur footprints."

The mine has long since closed, but fortunately, in 1964, geologists and the Queensland Museum mapped the trackway and made plaster casts, now used in current research.

"We made a virtual 3D model of the dinosaur footprint that was emailed to team members across the world to study," Mr Klein said.

"The more we looked at the footprint and toe impression shapes and proportions, the less they resembled tracks made by predatory dinosaurs -- this monster dinosaur was definitely a much friendlier plant-eater.

"This is still a significant discovery even if it isn't a scary Triassic carnivore.

"This is the earliest evidence we have for this type of dinosaur in Australia, marking a 50-million-year gap before the first quadrupedal sauropod fossils known."

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