Oldest remains of insects from bed bug genus found in Oregon

Common bed bug (Cimex lectularius) first nymph slide plate.

A cave in southern Oregon that is the site of some the oldest preserved evidence of human activity in North America was also once home to not-too-distant cousins of the common bed bug.

In research to be published next week in the Entomological Society of America's Journal of Medical Entomology, a pair of archaeologists describe remains found in caves near Paisley, Oregon, that represent the oldest specimens of insects from the genus Cimex ever found, ranging between 5,100 and 11,000 years old.

The remains were identified as relatives of the bed bug, Cimex lectularius, but they were "not the bed bug we all know and love from hotel rooms," says Martin E. Adams of Paleoinsect Research and co-author on the study with Dennis L. Jenkins of the Museum of Natural and Cultural History at the University of Oregon. The species in the Paisley Five Mile Point Caves (Cimex pilosellus, Cimex latipennis, and Cimex antennatus) are all parasites of bats.

Previously, the oldest remains of "cimicids" ever found were just 3,500 years old, found in Egypt in 1999, meaning the remains found at the Paisley Caves are the oldest Cimex specimens by a wide margin, and they raise some interesting questions for researchers about how cimicids have interacted (or not) with humans in the past.

Cimex lectularius and Cimex hemipterus are the two bed bug species that are known to parasitize humans, widely believed to have adapted to that role thousands of years ago when humans shared caves with bats in Europe, Asia, and Africa. The species found in the Oregon caves, however, never made that jump, and Adams says it's unclear why not.

"Were the cimicid populations too small to establish themselves outside the caves, or were the host populations too small?" Adams says. "Given that Paisley Caves was only a seasonal occupation area for human hunter-gatherers, did the humans move around too much, or were the bugs not able to withstand the environment outside the caves for very long? Or, were there other constraints involved? I'm working on these last few archaeological questions right now."

The identification of the three Cimex species may also offer some clues to climactic trends during the eras they were dated to, Adams says. Cimex antennatus, for instance, tends to favor the warmer climates of California and Nevada. "The presence of warm-tolerant cimicids in the caves, such as Cimex antennatus, may suggest that climatic conditions at Paisley Caves 5,100 years ago were similar to what Cimex antennatus enjoys today in its current range."

From Science Daily

The World's Most Venomous Scorpion Caught on Camera in Strike Mode

The world's most lethal scorpion, the death stalker, has been caught on high-speed camera for the first time lashing out with its lethal stinger, scientists reported Tuesday.

A comparison of half a dozen scorpion species shown in ultra-slow motion revealed an unsuspected variety of strike modes, they reported in the journal Functional Ecology.

The death stalker had the fastest lunge of all, with its venomous stinger snapping over its head like a whip at 130 centimeters (51 inches) per second.

It has a no-nonsense trajectory, moving straight towards its target before flicking upward. The emperor scorpion — the world's largest — has a similar open strike.

Other species, such as the black spitting scorpion, which can squirt venom at a distance, and various members of the hottentotta genus, strike with a more circular motion, forming an "O".

"We found that different 'tail' shapes" — some slim, some fatter — "appear to permit different strike performances," said senior author Arie van der Meijden, a professor at the University of Porto in Portugal.

To record and analyse the lightning-fast strikes, van der Meijden and his team built a small platform surrounded by mirrors on all four sides.

They filmed the scorpion strikes from above with a video camera at 500 frames per second, and then created 3D models with computers.

"Just taking them out of their container and putting them in the arena was enough to get them in stinging mood," van der Meijden said.

"All that was necessary to make them strike was touching their pincers with a thin piece of wire."

Next on the research agenda is to figure out the evolutionary forces which explain why the strike patterns are so varied.

It could be "related to the kind of predators they need to defend themselves against," van der Meijden told AFP.

The differences could also arise from the fact that some scorpions rely less on their tail stingers, and more on their pincers to ward off a threat.

Scorpions use their defensive arsenal against bats, snakes, lizards and other predators.

They also use their stinger to catch prey, and during mating.

A 2008 study in the journal Acta Tropica estimated that more than 3,000 people die every year from scorpion bites.

Read more at Discovery News

Medieval Villagers Hacked Their Dead to Pieces in Fear of Zombie Apocalypse

Composite diagram showing distribution of cut marks in the remains.

Researchers may have uncovered the first scientific evidence of a “zombie madness” that obsessed medieval England, according to a study of 137 human bones that were excavated from a deserted English village.

Dating from the 11th to 14th centuries, the skeletal remains were reduced to chopped, smashed, and burnt fragments in an apparent attempt to forestall revenants rising from the grave.

The bones were recovered in the 1960s from a pit at the site of Wharram Percy, a long-abandoned village in rural Yorkshire, but were never examined closely until now.

Gruesome evidence of extensive human activity was immediately clear.

“Some of the bones showed sharp force marks, signs of burning and perimortem breakage,” Simon Mays, human skeletal biologist at Historic England, Alistair Pike, professor of archaeological sciences at the University of Southampton, and their colleagues wrote in the Journal of Archaeological Science: Reports.

While they considered starvation cannibalism as a possible cause, the researchers said they had ruled out a scenario in which the remains were cannibalized by villagers who were enduring one of the 12 known famines that occurred in England between 1066 and 1300.

“The patterns of breakage and cut marks on the bones are not consistent with the removal of flesh for eating,” Pike told Seeker.

Rather than indicate starvation cannibalism, the breakage, burning, and knife and chop marks on the skeletal remains appear to be consistent with dismemberment and decapitation, which would reflect the dark side of medieval beliefs.

The most likely explanation, according to Mays, is that the bones are “the remains of corpses burnt and dismembered to stop them walking from their graves.”

“Belief in revenants was widespread in Medieval northern and western Europe. Revenants were usually malevolent, spreading disease and physically assaulting the living,” the researchers wrote. “Methods of dealing with the undead involved physical and/or spiritual means, with an emphasis on the former. The most usual way was to dig up the body and subject it to mutilation (particularly decapitation) and burning.”

Osteological examination of the 137 bones revealed that they belonged to at least 10 individuals, ranging in age from two to 50 years old.

Monastic documents describe the behavior of the restless undead and detail how to treat a body to prevent it from rising again.

The most common way was to dig up the corpse, which was mutilated and decapitated to destroy its integrity and burned, rendering it unrecognizable.

“Our research is the first archaeological evidence for such treatment in the UK,” Pike said. “It tells us that the fear of revenant corpses was real. People really did believe that corpses can rise from the dead.”

The Wharram Percy bones show a total of 76 sharp-force marks, mainly knife-marks, on the upper body parts. The marks were made “with a fine knife drawn across the bone,” the researchers noted.

“The knife marks can be interpreted in terms of dismemberment or other mutilation of the body, and those in the head and neck area may be associated with decapitation,” they wrote.
 
They added that at least 17 bones show evidence for low-temperature burning, while six long bones feature breakage that occurred at or sometime after death.

Why these 10 individuals would have been treated by the villagers in this way, or elicited such fear, remains a mystery.

“We don't know,” Pike said. “We have historical accounts of how the dead who may have been killed suddenly, or wronged in some way, come back to life and cause trouble.”

He added that no frightening diseases were detected from the bones.

“We found just a few cases of joint disease, but with a similar frequency to the individuals buried in the nearby graveyard, so there is no reason to believe these individuals were unusual,” he remarked.

Strontium isotopic analyses in the teeth suggest that the people whose corpses were mutilated likely grew up in an area close to where they were buried, possibly in the village.

“This was surprising to us, as we first wondered if the unusual treatment of the bodies might relate to their being from further afield,” Pike said.

Read more at Discovery News

Stretching the boundaries of neural implants

Researchers have developed a rubber-like fiber, shown here, that can flex and stretch while simultaneously delivering both optical impulses, for optoelectronic stimulation, and electrical connections, for stimulation and monitoring.

Implantable fibers have been an enormous boon to brain research, allowing scientists to stimulate specific targets in the brain and monitor electrical responses. But similar studies in the nerves of the spinal cord, which might ultimately lead to treatments to alleviate spinal cord injuries, have been more difficult to carry out. That's because the spine flexes and stretches as the body moves, and the relatively stiff, brittle fibers used today could damage the delicate spinal cord tissue.

Now, researchers have developed a rubber-like fiber that can flex and stretch while simultaneously delivering both optical impulses, for optoelectronic stimulation, and electrical connections, for stimulation and monitoring. The new fibers are described in a paper in the journal Science Advances, by MIT graduate students Chi (Alice) Lu and Seongjun Park, Professor Polina Anikeeva, and eight others at MIT, the University of Washington, and Oxford University.

"I wanted to create a multimodal interface with mechanical properties compatible with tissues, for neural stimulation and recording," as a tool for better understanding spinal cord functions, says Lu. But it was essential for the device to be stretchable, because "the spinal cord is not only bending but also stretching during movement." The obvious choice would be some kind of elastomer, a rubber-like compound, but most of these materials are not adaptable to the process of fiber drawing, which turns a relatively large bundle of materials into a thread that can be narrower than a hair.

The spinal cord "undergoes stretches of about 12 percent during normal movement," says Anikeeva, who is the Class of 1942 Career Development Professor in the Department of Materials Science and Engineering. "You don't even need to get into a 'downward dog' [yoga position] to have such changes." So finding a material that can match that degree of stretchiness could potentially make a big difference to research. "The goal was to mimic the stretchiness and softness and flexibility of the spinal cord," she says. "You can match the stretchiness with a rubber. But drawing rubber is difficult -- most of them just melt," she says.

"Eventually, we'd like to be able to use something like this to combat spinal cord injury. But first, we have to have biocompatibility and to be able to withstand the stresses in the spinal cord without causing any damage," she says.

The team combined a newly developed transparent elastomer, which could act as a waveguide for optical signals, and a coating formed of a mesh of silver nanowires, producing a conductive layer for the electrical signals. To process the transparent elastomer, the material was embedded in a polymer cladding that enabled it to be drawn into a fiber that proved to be highly stretchable as well as flexible, Lu says. The cladding is dissolved away after the drawing process.

After the entire fabrication process, what's left is the transparent fiber with electrically conductive, stretchy nanowire coatings. "It's really just a piece of rubber, but conductive," Anikeeva says. The fiber can stretch by at least 20 to 30 percent without affecting its properties, she says.

The fibers are not only stretchable but also very flexible. "They're so floppy, you could use them to do sutures and deliver light at the same time," she says.

"We're the first to develop something that enables simultaneous electrical recording and optical stimulation in the spinal cords of freely moving mice," Lu says. "So we hope our work opens up new avenues for neuroscience research." Scientists doing research on spinal cord injuries or disease usually must use larger animals in their studies, because the larger nerve fibers can withstand the more rigid wires used for stimulus and recording. While mice are generally much easier to study and available in many genetically modified strains, there was previously no technology that allowed them to be used for this type of research, she says.

"There are many different types of cells in the spinal cord, and we don't know how the different types respond to recovery, or lack of recovery, after an injury," she says. These new fibers, the researchers hope, could help to fill in some of those blanks.

Read more at Science Daily

Surprise discovery of Europe's first cave fish

This photograph shows a male cave loach of 8.5 cm body length.

Researchers reporting in Current Biology on April 3 have discovered the first European cave fish. A hobby cave diver first sighted the fish, a loach in the genus Barbatula, living in a hard-to-reach, underground water system in South Germany.

"The cave fish was found surprisingly far in the north in Southern Germany," says Jasminca Behrmann-Godel of Germany's University of Konstanz. "This is spectacular as it was believed before that the Pleistocene glaciations had prevented fish from colonizing subterranean habitats so far north."

Their genetic studies of the fish together with knowledge on the geological history of the region suggest that the cave loach arose recently, within the last 20,000 years.

"It was only when the glaciers retreated that the system first became a suitable habitat for fish," says Arne Nolte from the University of Oldenburg/Max Planck Institute for Evolutionary Biology, Plön.

Despite that relatively short period of evolutionary time, the fish already show adaptations characteristic of "real" cave fish. As Jörg Freyhof from the Leibniz Institute for Freshwater Ecology and Inland Fisheries (IGB) Berlin explains, their eyes are much smaller, appearing almost as if curved inwards, and their color has all but disappeared. The fish also have elongated whisker-like barbels on their heads and larger nostrils than related fish living closer to the surface.

Joachim Kreiselmaier first sighted the loaches in August 2015 while exploring the deepest parts of the Danube-Aach system, which can only be reached under particularly dry conditions in summer and fall. Noticing that the fish were "strange looking" to him, he snapped some photos and showed them to the hobby geologist and co-author Roland Berka, who contacted Behrmann-Godel, knowing her from former work. Study co-author and fish taxonomist Freyhof later confirmed that the fish could be showing cave adaptations.

"It took someone with the 'right eye' to realize that this might be something special and I believe that, on top of the right conditions and the difficult trip, this discovery depended on an exceptional diver like Joachim to realize in the first place that the fish might be special," Behrmann-Godel says.

"No more than 30 divers have ever reached the place where the fish have been found," Kreiselmaier says. "Due to the usually bad visibility, strong current, cold temperature, and a labyrinth at the entrance, most divers do not come back again for diving."

But that didn't stop Kreiselmaier. In November 2015, on another dive, Kreiselmaier succeeded in catching a live specimen, which allowed the researchers to study its features in greater detail. The following year, he caught four more fish, enabling further study of the loach's form and genetics. Based on morphological and genetic comparison to surface fish caught upstream and downstream of the cave, the researchers report that the cave loaches are indeed an isolated population and the first known European cave fish.

The findings show that adaptation to subterranean habitats can be fast -- requiring only a few thousand years. They also come as reminder that "wonders of nature can turn up anywhere, even in your own backyard," Freyhof notes.

Read more at Science Daily

New indications of gradual decline of dinosaurs before the end of the cretaceous period

Landscape in the Paredon area: There the researchers encountered fossil imprints while conducting paleontological research.

According to the latest research results of a German-Mexican team of geoscientists, the gradual decline of the dinosaurs and pterosaurs presumably came before the impact of the Chicxulub asteroid and the global mass extinction at the end of the Cretaceous Period. Studies under the direction of Prof. Dr Wolfgang Stinnesbeck of Heidelberg University and Prof. Dr Eberhard Frey of the State Museum of Natural History Karlsruhe also indicate that bird species spread and diversified at the same time the dinosaurs disappeared. Their results were published in the journal Geological Society of America Bulletin.

While conducting paleontological research in northeastern Mexico, the scientists came upon sedimentary rock deposited toward the end of the Cretaceous Period that evidenced an enormous diversity of fossils, including the tracks of birds, dinosaurs and pterosaurs. "Most of the imprints come from at least five different species of birds; dinosaur tracks, however, are rare. Only a single footprint comes from a predatory dinosaur," explains Prof. Stinnesbeck. The finds therefore indicate a gradual decline of the dinosaurs with a simultaneous increase in the diversity of birds even before the end of the Cretaceous Period. "Until now, it was generally assumed that the dinosaurs died out first and bird species diversified afterward," states the researcher. "Our data, however, substantiate the theory that birds ascended before dinosaurs became extinct."

Fossil analysis also showed that the decline of the dinosaurs occurred gradually, with probably only a few species surviving until the end of the Cretaceous Period. The extinction of the dinosaurs is therefore not -- as science frequently assumes -- due to the impact of the Chicxulub asteroid that struck Earth more than 65 million years ago. "For most of the dinosaurs and pterosaurs, this strike no longer had any effect," explains Prof. Stinnesbeck. Even the group of cephalopods, the so-called ammonites, was not annihilated by the asteroid strike at the end of the Cretaceous Period. According to Prof. Stinnesbeck, fossil finds of the Sphenodiscus pleurisepta ammonite show their successive decline beyond the Cretaceous Period. "The effects of the Chicxulub impact were therefore not the cause of a global mass extinction, which probably came about considerably less catastrophically than previously assumed," states the Heidelberg researcher.

From Science Daily

Mutant lifestyles: Researchers uncover a potent genetic element in Earth's smallest life forms

An ultra-small bacterial cell (scale bar is 100 nanometers) is thought to be a relative of the microorganisms that encode diversity-generating retroelements.

It's the stuff of science fiction, though there's nothing fiction about it: Researchers have discovered a multitude of previously unidentified microorganisms possess a genetic element that enables them to self-mutate.

What's more, these organisms are so great in number that they dramatically expand the diversity of the tree of life.

"These microorganisms can be 500 times smaller than bacteria like E. Coli," said UC Santa Barbara microbiologist David Valentine. "They also do unusual things to some of the key genes used for identification, like splitting them into pieces small enough to render them invisible to scientific surveillance. This combined with their ultra-small size explains why they were missed until recently."

To pinpoint these miniscule organisms -- tiny enough to pass through filters that capture traditional microbes -- the scientists turned to groundwater samples from a Colorado aquifer. Analyzing numerous genomes therein, they detected a prevalence of an unusual genetic element they had encountered once before: diversity-generating retroelements (DGRs). The new findings appear in the journal Nature Microbiology.

Co-author Valentine, a professor in UCSB's Department of Earth Science, along with postdoctoral scholar Blair Paul and co-authors from UC Berkeley, UC San Diego and UCLA, show that these DGRs are active in sprawling lineages of recently discovered phyla: two classes of archaea -- primitive, single-celled, bacteria-like microorganisms -- and among potential new bacterial candidates in the biological tree of life. These new biological classes appear to disproportionately harbor DGRs, which enable them to target their own genes for accelerated mutation.

Lead author Paul analyzed more than 500 genomes out of a pool of 2,500 and found that the majority of a certain class of archaea, as well as a yet-to-be-characterized phyla closely related to bacteria, appear to have DGRs. In fact, many possess multiple DGRs.

"These microorganisms are so small they have minimized the amount of information they can code, so they are probably not totally self-reliant," said Valentine, also a professor in UCSB's Marine Science Institute. "This means that they engage in some form of either symbiosis or parasitism. If a microorganism shrinks down its genome and its cell to this very minimal lifestyle, it has to have mechanisms that allow it to evolve new capabilities but also to shed unneeded ones."

Valentine noted that the DGR mechanism might allow these organisms to do both. Or perhaps, he posited, they optimize to the point where it's no longer beneficial to mutate and have to rid themselves of the capability.

"The finding that DGRs are relatively widespread in tiny bacteria with symbiotic lifestyles is of great interest because these elements likely contribute to the incredible diversity of protein sequences found in these organisms," said co-author Jill Banfield, a professor of earth and planetary sciences at UC Berkeley.

While very little is known about how DGRs self-regulate, scientists are finding that these elements are able to guide and target specific sites for mutation. By examining DNA sequence from the genomes, the researchers saw recent mutation activity and observed the mechanism in action by virtue of its RNA being transcribed.

"One of the reasons we were able to see the pattern of mutations in the DNA was because the data set recovered such a depth of genomes that we could see the variability within them," Paul said.

The mechanism targets only one of the four different nucleotides (A, C, G, T) that form the basic structure of nucleic acids such as DNA. Nucleic acid synthesis and degradation require enzymes to facilitate either process. In fact, a biochemical artifact of an enzyme was what first revealed this mechanism to the UCSB investigators. A distinctive signature and location as well as only A mutations are hallmarks of this mechanism.

"There are similar proteins that don't mutate only A but are error prone," Paul explained. "We think that this enzyme is similarly prone to creating mutations."

Because the scientists are dealing with new organisms, they have not yet been able to determine what the vast majority of the diversified proteins do.

"An important question is whether these mutations alter the proteins that the genes encode or are they meant to interrupt the genes themselves and target them for removal from the genome?" Paul asked. "If this mechanism forces mutations that cause some genes to go defunct, it could be associated with evolutionary benefits."

"This discovery reveals how rapid evolution happens in some of Earth's smallest and most common, yet least-known, microbes," says Mike Sieracki of National Science Foundation's Division of Ocean Sciences, and a director for the Dimensions of Biodiversity program, which sponsored the research.

Read more at Science Daily

Tyrannosaurs show their sensitive side

A team of researchers, including UNM Honors College Professor Jason R. Moore, has found a new species of tyrannosaur dinosaur -- the most popular of the prehistoric creatures. After the fossils were pulled out of the muddy banks of a Montana river, the team was able to analyze the texture of the facial bones of the new species. The findings suggest that the face of tyrannosaurs was covered in a scaly protective layer with a high degree of tactile sensitivity, similar to crocodiles.

A team of researchers, including UNM Honors College Professor Jason R. Moore, has found a new species of tyrannosaur dinosaur -- the most popular of the prehistoric creatures.

After the fossils were pulled out of the muddy banks of a Montana river, the team was able to analyze the texture of the facial bones of the new species. The findings suggest that the face of tyrannosaurs was covered in a scaly protective layer with a high degree of tactile sensitivity, similar to crocodiles.

"Being a tyrannosaur, they had really small arms," says Moore. "They wouldn't be able to interact with their environment with their hands the way mammals do -- find food, build nests, tend to eggs and young. In order to do these things, Daspletosaurus needed to use its feet or head. The discovery and analysis of the tyrannosaur shows that the dinosaur had a developed face sensitivity similar to the sensitivity in our finger tips, suggesting it could use its snout for all those complex ecological interactions, similar to the way crocodiles do today."

An investigation by a team of scientists from Wisconsin, Australia, Louisiana, Montana and New Mexico has identified and named the new species of the tyrannosaur clan: Daspletosaurus horneri -- "Horner's Frightful Lizard."

The species is named for the renowned dinosaur paleontologist, John "Jack" R. Horner, formerly curator at the Museum of the Rockies (MOR) in Bozeman, Montana. The tyrannosaur's name honors his discoveries of numerous dinosaur fossils and his mentorship of so many students that launched them on to accomplished scientific careers. The name-bearing specimens are stored in the research collections of the MOR.

The fossil resources of Montana, where the new tyrannosaur was found, are central to studies of dinosaur evolution.

"Montana, similar to many Rocky Mountain states, has lots of rock exposed at the right time and right environment to contain dinosaurs," says Moore. "The fossils are found preserved in ancient river channels and flood plains. If you know what you're looking for, they are widespread."

The research is led by Thomas Carr of Carthage College's Department of Biology in Wisconsin, an expert on the evolution and growth of Tyrannosaurus rex and its closest relatives, collectively called tyrannosaurs.

The family tree

In addition to adding a new species to the tyrannosaur family tree, the team's research provides new information about the mode of evolution and life appearance of tyrannosaurs, specifically the face.

This latest study, published in Nature Publishing Group's Scientific Reports, found evidence for a rare, nonbranching type of evolution in tyrannosaurs and that tyrannosaurs had scaly, lipless faces and a highly touch-sensitive snout.

"Daspletosaurus horneri was the youngest, and last, of its lineage that lived after its closest relative, D. torosus, which is found in Alberta, Canada," says Carr. "The geographic proximity of these species and their sequential occurrence suggests that they represent a single lineage where D. torosus has evolved into D. horneri."

Moore elaborated, "One of the difficulties in demonstrating this style of evolution is establishing that the different species don't overlap in time. The new radiometric dates we measured help support this temporal separation between D. torosus and D. horneri."

The research confirms that the ages of the two species shows that the evolution of the dinosaur was slow -- happening over a span of 2.3 million years.

The team's work literally changes the face of tyrannosaurs, which they found was covered by a lipless 'mask' of large flat scales and extensive patches of armor-like skin. This conclusion results from comparison of tyrannosaur skulls with those of crocodylians, birds and mammals, and earlier work by other researchers who had matched bone texture with different types of skin covering.

Jayc Sedlmayr, professor at the Louisiana State University Health Sciences Center New Orleans, explained, "Much of our research ... was generated from lab based comparative anatomy, where you get arms deep in 'blood and guts' dissecting birds -- living dinosaurs and crocodilians -- their closest living relatives."

The crocodile connection

"It turns out that tyrannosaurs are identical to crocodylians in that the bones of their snouts and jaws are rough, except for a narrow band of smooth bone along the tooth row," explained Carr. "We did not find any evidence for lips in tyrannosaurs: the rough texture covered by scales extends nearly to the tooth row, providing no space for lips."

"However, we did find evidence for other types of skin on the face, including areas of extremely coarse bone that supported armor-like skin on the snout and on the sides of the lower jaws. The armor-like skin would have protected tyrannosaurs from abrasions, perhaps sustained when hunting and feeding."

The researchers found that, like in crocodylians, the snout and jaws of the tyrannosaurs are penetrated by numerous small nerve openings, allowing hundreds of branches of nerves to innervate the skin, producing a sensitivity similar to that of human fingertips.

Read more at Science Daily

A badger can bury a cow by itself

This is a camera trap image of a badger burying a calf carcass in Utah's Grassy Mountains, January 2016.

While studying scavenger behavior in Utah's Great Basin Desert, University of Utah biologists observed an American badger do something that no other scientists had documented before: bury an entire calf carcass by itself.

Watch a video of the badger here: https://www.youtube.com/watch?v=dsHiOwR7cfc&feature=youtu.be

While badgers and their relatives are known to cache food stores, this is the first known instance of a badger burying an animal larger than itself. The finding suggests that badgers may have no limit to the size of animal they can cache, and that they may play an important role in sequestering large carcasses, which could benefit cattle ranchers in the West. The study is published in Western North American Naturalist.

"We know a lot about badgers morphologically and genetically, but behaviorally there's a lot of blank spaces that need to be filled," says senior Ethan Frehner, first author on the paper documenting the badger behavior. "This is a substantial behavior that wasn't at all known about."

The work was funded by a National Science Foundation Graduate Research Fellowship to doctoral candidate Evan Buechley.

Scavenger bait

The team didn't originally intend to study badgers. In January 2016, Buechley set out seven calf carcasses in Utah's Grassy Mountains, west of Salt Lake City. Each carcass was staked down and equipped with a camera trap to document what scavengers visited which carcasses. Buechley, who studies vultures and other avian scavengers, hoped to learn more about the ecology of scavengers in the Great Basin during the winter.

Buechley went out to check on the carcasses after a week, and found that one was missing.

"When I first got there I was bummed because it's hard to get these carcasses, to haul them out and set them up," he says. "I thought 'Oh, well we've lost one after a week.'"

He searched around the area, thinking that perhaps a coyote or mountain lion had dragged the carcass away, but after finding nothing, returned to the site and realized the ground where the carcass had been was disturbed. "Right on the spot I downloaded the photos," he says, "We didn't go out to study badgers specifically, but the badger declared itself to us."

A happy badger

Little was previously known about badger behavior, Frehner says. "They're an enigmatic species. A substantial amount of their lifetime is spent either underground or a lot of nocturnal behavior, so it's hard to directly observe that." Camera traps, a relatively new tool for researchers, made it possible to observe more natural behaviors.

In the photos, Buechley saw the badger dig around and beneath the carcass, which disappeared into the cavity created by the excavation. "Watching badgers undertake this massive excavation around and underneath is impressive," Frehner says. "It's a lot of excavation engineering they put into accomplishing this."

Camera trap records show that the badger completely buried the roughly 50-pound carcass over the course of five days, and then spent around two weeks in his underground burrow before leaving and intermittently returning to the burrow for the next few weeks until early March. According to the researchers, badgers cache food to isolate it from other scavengers and to keep it in an environment where it will last longer. "Like putting it in the fridge," Buechley says. Previously, biologists saw badgers caching rodents and rabbits, but never an animal larger than itself.

Senior Tara Christensen assembled a time-lapse video of the burial, which shows the badger sitting contently atop the burrow. Buechley says, "Not to anthropomorphize too much, but he looks like a really really happy badger, rolling in the dirt and living the high life."

Badgers' ecological role

Another badger, at another site in the same study, also attempted to bury a calf carcass, suggesting that the behavior is likely widespread for badgers. It's unclear whether badger relatives, called mustelids, can also cache such large animals. Other mustelids such as weasels, wolverines and martens aren't as specialized for digging as badgers are, but one account does document a fisher caching a black bear carcass under branches and bracken.

Buechley says that large-animal caching could have a large impact in the harsh and sparse ecosystem of the Great Basin. "There's not a lot of resources out there," he says. "A large dead ungulate can provide a ton of resources. So far on the carcasses we've put out, we've had turkey vultures, golden eagles, many ravens, bobcats, kit fox and coyote, so there's a lot of animals that could be using this resource, and the badger just monopolizes it."

The badger could also provide an ecological service to ranchers. Many ranchers see badgers as pests, because they dig burrows through rangeland and can eat chickens. But if badgers can bury a calf, they may bury other carrion before any diseases incubating in the carcass can infect other cows. "It's not beneficial to have rotting carcasses out among your other cattle because of disease vectors," Frehner says. Christensen adds, "Keeping large predators away is a big deal for a lot of ranchers. You could argue that if the carcasses are being buried, they're not going to be attracting large predators."

Both Frehner and Christensen participated in this study as undergraduates, an experience that gave them an early insight into the research process. "Doing research and getting involved in a lab is a great way to see how science is done," Christensen says. "I've learned a lot in the last few months about data analysis and using these things to find real results."

Frehner adds, "Writing the paper has been a substantial learning experience for me that I don't think I would have gotten any other way."

Read more at Science Daily

Massive, computer-analyzed geological database reveals chemistry of ancient ocean

Julia Wilcots, a Madison native who was then at Princeton University, at a rock quarry in Shorewood Hills, Wisconsin. The layers at her head and chest level are both composed of different types of stromatolites.

A study that used a new digital library and machine reading system to suck the factual marrow from millions of geologic publications dating back decades has unraveled a longstanding mystery of ancient life: Why did easy-to-see and once-common structures called stromatolites essentially cease forming over the long arc of earth history?

Stromatolites are contorted layers of sediment formed by microbes, and they are often found in limestone and other ancient sedimentary rocks deposited beneath oceans.

"Geologists have known for a long time that stromatolites were abundant in shallow marine environments during the Precambrian, before the emergence of multi-cellular life" more than 560 million years ago, says Jon Husson, a post-doctoral researcher and co-author of a study now online in the journal Geology. "But, stromatolites are rare in the ocean today."

The new study measures the slide in stromatolite prevalence based on descriptions of rocks sifted from more than 3 million scientific publications.

"Paleontologists have largely attributed the decline in stromatolites to the evolution of animals, starting some 560 million years ago," says Shanan Peters, a professor of geoscience at University of Wisconsin-Madison and study first author. "Many multi-cellular animals, like snails, eat microbes. The evolution of these big microbe-grazing animals hit 'reset' on the stromatolite's world. Or so the story has gone."

The new study found a weak correlation between stromatolite occurrence and the diversity of animals, but a stronger link to seawater chemistry.

"The best predictor of stromatolite prevalence, both before and after the evolution of animals, is the abundance of dolomite in shallow marine sediments," says Husson. Dolomite is a high-magnesium variety of carbonate, the type of sediment that forms limestone. Dolomite is harder to make than low-magnesium carbonate and it forms today in only a narrow range of marine environments.

When the ocean water is super-saturated with carbonate, "that can make it easier for things like stromatolites to form," says Husson. "In Lake Tanganyika [Africa], there are stromatolites forming today, even though there are animals everywhere, snails and fish. The lake is super-saturated with carbonate, and it's begging to be precipitated. The microbes come along and help it to precipitate, and the result is an abundance of stromatolites." Elevated carbonate saturation can also help the formation of dolomite, thereby driving the correlation with stromatolites found in this study.

Measuring the prevalence of stromatolites through all Earth history is difficult because counting the number of stromatolites alone is not sufficient. You must also know how many rocks could potentially have stromatolites, but do not.

The big innovation of this study is the interplay of a new type of digital library and machine reading system called GeoDeepDive with a geological database called Macrostrat. Both were spearheaded by Peters at UW-Madison.

GeoDeepDive is a digital library built on high throughput computing technology that can "read" millions of papers and siphon off specific information. To date, the GeoDeepDive library contains more than 3 million scientific publications from all scientific disciplines; some 10,000 new published papers are added daily.

Macrostrat is a database describing the known geological properties of North America's upper crust, at different times and depths.

The massive computing capacity at UW-Madison's Center for High Throughput Computing and HTCondor system, the brainchild of UW-Madison computer scientist Miron Livny, powers GeoDeepDive. Combining the digital library with the geological database allowed the researchers to estimate, at different time periods, the percentage of shallow marine rocks that actually have stromatolites.

The study began in the summer of 2015, when the third author, Julia Wilcots, a Madison-native who was then an undergraduate at Princeton, asked Peters for a summer project. "In my typical fashion I gave Julia a few options," Peters says. "She picked stromatolites, so I said, 'Okay, go do it!' With minimal help from us, she developed a working application to discover and extract every mention of stromatolites from our library."

Among 10,200 papers that mentioned stromatolites, "our program was able to extract 1,013 with a name of a rock unit, which enabled us to link stromatolite occurrences to Macrostrat," says Husson.

Wilcots did not have to travel to see stromatolites, Peters says. "In Madison, we are sitting on top of rocks recording one of the biggest rises in stromatolite abundance -- at least during the age of animals."

Scientists long ago observed that stromatolites started a long decline just before the start of the Cambrian era, but that decline represented a "fundamental question of paleobiology," Husson says. "Stromatolites are the oldest fossils that are visible to the naked eye. If you look at rock that is a billion years old, the chance for seeing evidence of life equals the chance of seeing stromatolites."

Beyond answering a fundamental question of Earth's history, the new study "allows us to do the kind of analyses that scientists used to only dream about, Peters says: 'If we could just compile all the published information on... anything!'

"Doing this study without GeoDeepDive would be all but impossible," Peters adds. "Reading thousands of papers to pick out references to stromatolites, and then linking them to a certain rock unit and geologic period, would take an entire career, even with Google Scholar. Here we got started with a talented undergrad working on a summer project. GeoDeepDive has greatly lowered the barrier to compiling literature data in order to answer many questions."

Another beauty of the big data, machine-reading approach is the baked-in capability for replication and improvement. "Now that this study has been done, we can run the stromatolite application again and again. We can refine the searches, and they will evaluate the new data that is being published all the time," Peters says. "So a rerun could make a better study, with minimal effort."

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