Iron Age Skeletons Found Buried With Turtles

Excavations at a site in southeastern Turkey has revealed the more than 2,500-year-old remains of a woman and a child who were buried with several previously slaughtered and butchered turtles.

Most of the turtles belonged to the Euphrates softshell species, known for their aggression.

The unique burial was found at Kavuşan Höyük, a multi-period mound site on the southern bank of the Tigris River, some six miles from the modern town of Bismil in Turkey.

Dated to the late Iron Age, which is known locally as the post-Assyrian period, the pit revealed the skeletons of a 6-7-year-old child and a woman aged between 45 and 55 years.

Lying face down, the infant, whose sex wasn't identified, had the left leg bent at the knee and the right leg fully extended. The right arm lay under the body, while the left was stretched above the shoulder, as if protecting the face.

"A broken iron fibula grave good that was placed next to the skull may indicate that the child was a girl," Rémi Berthon, archaeozoologist at the National Museum of Natural History in Paris, France, Güriz Kozbe, professor of archaeology at the Batman University, Turkey, and colleagues wrote in the latest issue of Antiquity.

Directly beneath the child, was the female skeleton, lying on her back in a semi-flexed position. No evidence of trauma related to a violent death was found in both skeletons.

Since ancient DNA analyses were not performed, the researchers have no information on the relationship between the adult women and the child.

“We know that the child and the woman were buried in a short time range because the woman’s skeleton, found just below the child, has not been disturbed when the child’s body was placed into the grave,” Berthon told Discovery News.

All around the edge of the pit, the archaeologists found numerous remains of turtles. Two carapaces and some scattered skeletal elements were also found in the middle of the grave.

One of the centrally deposited shells belonged to a spur-thighed tortoise (Testudo graeca), 17 remains were of Euphrates soft-shelled turtles (Rafetus euphraticus) and three belonged to Middle Eastern terrapins(Mauremys caspica).

“Although the Middle Eastern terrapin is very common in eastern Turkey, this is the first evidence of its use as a grave good. Finding Euphrates soft-shelled turtles in a burial is unprecedented as well,” Berthon said.

Characterized by an olive-green leathery skin that covers the carapace, the Euphrates softshell turtles are primarily known as having a carnivorous diet, although they also feed on plants and vegetables.

“They are also scavengers and have frequently been observed feeding on the drifting carcasses of various mammals, which can be as large as a horse,” the researchers wrote.

The Euphrates soft-shelled turtles that were placed in the grave were clearly butchered.

“Some anatomical parts are missing, suggesting they were taken away, probably for consumption in the frame of a funerary feasting,” Berthon said.

The tortoise and terrapins, meanwhile, were seemingly neither butchered nor consumed during the funerary rites.

“Only their empty carapaces were used as grave goods,” the researchers noted.

Chelonians had a strong symbolic value in the ancient Near East and were strongly connected with afterlife.

“We call them psychopomp animals, responsible for escorting newly deceased souls to the afterlife, Berthon said. “The ritual evidenced in the burial probably attests to the peculiar social status of the deceased."

Read more at Discovery News

Rare Charles Darwin Letter Will Be Sold at Auction

A rare handwritten letter by famed naturalist Charles Darwin to a British marine biologist will be auctioned off Thursday, in which he details plans to release a corrected version of the book “The Origin of Species.”

In the letter, Darwin also expresses excitement about the work of the marine biologist George Charles Wallich on brittle starfish but also wonders about his findings on basaltic pebbles. He also thanks Wallich for sending his book “Notes on the Presence of Animal at Vast Depth in the Sea” and asks about Wallich’s observations regarding shell deposits, which are important “for me in relation to some few passages in my Book.”

“This signed letter concerning deep ocean discoveries shows Darwin’s interest in biological life and geology at the ocean bottom and his meticulous efforts at clarifying the findings of Wallich,” Nate Sanders, owner of Nate D. Sanders Auctions, said in a statement. “Darwin’s attention to details demonstrates why he was such a superb naturalist.”

It is the latest of several Darwin letters to be auctioned off. In September, a Darwin letter in which he stated he did not believe in God was sold for $197,000 at Bonhams New York. That was three times the previous record of $59,142 for a four-page letter that Darwin had penned to his niece.

A month later, Bonhams sold a letter from Darwin on the sex life of barnacles for $25,000.

This letter was written on Dec. 12, 1860, about a year after the publication of “The Origin of Species.” The book is considered the foundation of evolutionary biology and introduced the idea that species evolved over generations through the process of natural selection.

Read more at Discovery News

Warming Slowdown Was Real, Scientists Say

A global warming slowdown has come and gone, but an academic brouhaha continues to boil over the nitty gritty details of what once was a great scientific mystery.

On Wednesday, a group of prominent scientists published a commentary faulting colleagues who have published papers downplaying or dismissing the significance of a 13-year slowdown in warming rates at the planet’s surface.

“We shouldn’t sweep the early 2000s warming slowdown under the rug,” said Penn State meteorology professor Michael Mann, one of 11 authors of the commentary published in Nature Climate Change.

Temperature measurements taken at the surface of the planet from 2001 to 2014 revealed a lull in the rate of global warming, sometimes called the “warming hiatus,” before spiking upward again. Then 2014 was the hottest year on record until the record was easily beaten in 2015.

Until 2009, scientists had little explanation for the phenomenon. By 2014, though, it was known that the slowdown was caused primarily by a phase in a slow-moving Pacific Ocean cycle, with fierce trade winds driving more heat than normal into ocean depths.

The slowdown at the planet’s surface coincided with a rise in temperatures in ocean depths, worsening sea-level rise.

“The temporary slowdown in no way implies that human-caused warming has ceased or slowed down,” Mann said. “It was temporarily masked by natural factors.”

Several recent papers have called into question whether the surface warming slowdown was significant. Some of the disagreements boil down to semantics; others relate to interpretations of data.

Wednesday’s commentary lauded the advances in climate science that helped solve the mystery of the slowdown, while rebuking other scientists whose research has concluded that the slowdown was insignificant or unimportant.

“Given the intense political and public scrutiny that global climate change now receives, it has been imperative for scientists to provide a timely explanation of the warming slowdown,” wrote the 11 scientists, who are based in Canada, England, Australia and the U.S. “Despite recently voiced concerns, we believe this has largely been accomplished.”

One of the studies singled out in the commentary was produced by National Oceanic and Atmospheric Administration scientists led by Thomas Karl, who directs the agency’s National Climatic Data Center.

Karl’s team believes some historical records of ocean temperatures are flawed, and they corrected them accordingly.  The result of that analysis led them to conclude in a paper published last year in Science that warming during the early 2000s was “far more similar” to the longer-term trends “than previously estimated.”

That surprise finding prompted Rep. Lamar Smith, a Republican from Texas who is chairman of the House Committee on Science, Space and Technology, to aggressively push for access to the government scientist’s emails, part of an investigation that others have characterized as a witch hunt.

Smith has argued that the NOAA study was “expedited to fit” the Obama Administration’s “aggressive” climate policies — a claim the agency strongly denies.

Karl on Wednesday stood by his work, saying “there is no disagreement” that temperatures and warming rates vary between decades. “We showed that one could not claim that the long-term warming trend was significantly different from the shorter period,” he said.

Wednesday’s commentary was a reminder that opposition to NOAA’s findings is not just from politicians and fossil fuel groups, but from researchers who are convinced that the warming slowdown was real — and worthy of a public conversation.

The new commentary included new analysis of temperature data that showed what the authors described as a “mismatch” between early-century rates of warming and rates projected by model simulations.

“We’re presenting results to support previous findings of reduced rates of surface warming,” said John Fyfe, a Canadian government climate scientist who coordinated publication of the commentary. “That essentially refutes the Karl et al. paper.”

Fyfe said he had “no doubt” that the commentary would be misused by climate science deniers, but that he had no hesitations about publishing it. “I don’t think we should be in the business of pandering to the climate deniers.”

Two other teams of scientists whose papers were critiqued in the commentary downplayed any differences in opinion, pointing to the consensus that global warming and natural variability both affected early-century surface temperatures.

“Their perspective is very much in line with our previously published work,” said Noah Diffenbaugh, one of four Stanford researchers who wrote a paper published last year in Climatic Change provocatively titled “Debunking the climate hiatus.” “Global warming has resulted in a long-term trend superimposed on natural climate variability.”

Another paper criticized in the commentary was published last year by the Bulletin of the American Meteorological Society. In it, three scientists led by University of Bristol cognitive psychology professor Stephan Lewandowsky concluded that “there is no evidence that identifies the recent period” of warming as “unique or particularly unusual.”

That paper argued against the use of the term “global warming hiatus,” or “pause,” which is sometimes used to describe the recent global warming slowdown.

Read more at Discovery News

Human Teeth Likely Shrank Due to Tool Use

Wisdom teeth may have shrunk during human evolution as part of changes that started with human tool use, according to a new study.

The research behind this finding could lead to a new way of figuring out how closely related fossil species are to modern humans, scientists added.

Although modern humans are the only surviving members of the human family tree, other species once lived on Earth. However, deducing the relationships between modern humans and these extinct hominins — humans and related species dating back to the split from the chimpanzee lineage — is difficult because fossils of ancient hominins are rare.

Teeth are the hominin fossils most often found because they are the hardest parts of the human body. “Teeth are central to how a fossil ancestor lived, and can tell us about which species they belonged to, how they are related to other species, what they ate, and how quickly or slowly they developed during childhood,” said lead study author Alistair Evans, an evolutionary biologist at Monash University in Melbourne, Australia.

Hominin teeth have shrunk in size throughout evolution, a trend perhaps most clearly seen with the wisdom teeth located at the back of the mouth, the researchers said. In modern humans, wisdom teeth are often very small or do not even develop, while in many other hominin species they were huge, with chewing surfaces two to four times larger than those of their modern human counterparts.

Previous research suggested this profound shrinking in modern human wisdom tooth size was due to the advent of cooking or other changes in diet unique to modern humans. However, Evans and his colleagues now suggest this shift may have begun much earlier in human evolution.

The scientists analyzed tooth size in modern humans and fossil hominins. They found that hominin teeth fell into two major groups. One group was composed of the genus Homo, which includes both modern humans and extinct human relatives. The other group was made up of early hominins preceding Homo, such as the australopiths, the first primates to walk on two feet.

In australopiths and other early hominins, the scientists found that teeth tended to get bigger toward the back of the mouth, with proportions that stayed constant regardless of the overall size of the teeth. However, in the genus Homo, the smaller all the teeth were, the smaller the teeth were toward the back of the mouth.

“There seems to be a key difference between the two groups of hominins — perhaps one of the things that defines our genus Homo,” Evans said in a statement.

This change in how teeth developed between genus Homo and earlier hominins may have occurred due to the advent of advanced tool use in the genus Homo, Evans said.

“It’s always been presumed that sometime in early Homo, we started using more advanced tools,” Evans told Live Science. “Tool use meant we didn’t need as big teeth and jaws as earlier hominins. This may then have increased evolutionary pressure to spend less energy developing teeth, making our teeth smaller.”

In modern humans, tooth-size reduction has reached the point where wisdom teeth are increasingly failing to develop, Evans said. “The advent of cooking made food easier to eat, meaning we didn’t need big teeth as much,” Evans said.

Prior work suggested there was a lot of variation in how teeth evolved in hominins. “Now we’re seeing some very simple, clear patterns in hominin tooth evolution instead,” Evans said. [Infographic: Human Origins – How Hominids Evolved]

These patterns could help researchers decide whether ancient hominins were members of genus Homo or not, Evans said.

“It’s been suggested a number of times over the past 20 years that maybe Homo habilis, often considered the earliest member of Homo, should be considered an australopith instead,” Evans said. “We found Homo habilis tooth proportions followed the australopith rule and not the Homo rule, which supports the argument that Homo habilis should be reclassified to something like Australopithecus habilis.”

This new work builds on previous experiments with mice that suggested teeth could influence each other during development. In this “inhibitory cascade model,” teeth that develop early can inhibit the size of teeth that develop later. These new findings suggest this mechanism underlying tooth size in mice and most mammals is seen in hominins as well, Evans said.

These findings suggest that by knowing the size of a single hominin tooth and the group to which it belongs, scientists could infer the size of the hominin’s remaining teeth with considerable accuracy. “Sometimes we find only a few teeth in a fossil,” Evans said. “With our new insight, we can reliably estimate how big the missing teeth were.”

Read more at Discovery News

Mystery Ocean Hum May be Migration Signal, or Fish Farting

Vast communities of migrating deep-sea marine life are the culprits behind a mysterious, low-frequency humming sound in the ocean, made as the creatures swim to and from the surface at feeding time.

The discovery, made by University of California, San Diego assistant research biologist Simone Baumann-Pickering, answers a long-standing question. The source of the hum has for years vexed marine biologists, as NPR reports. They knew the sound wasn't consistent with whale calls or other marine mammals, such as dolphins, communicating.

Now, thanks to high-sensitivity undersea audio recordings, Baumann-Pickering says it's animals such as fish, jellies, shrimp, and squid living in what’s known as the ocean’s mesopelagic zone – a range 200 to 1000 meters (660 to 3300 feet) below the surface – that are behind the sound.

Creatures in the mesopelagic neighborhood live deep down, in a dark world where the sun barely shines and there’s not exactly a bounty of food. So each night, with the safety of darkness, they venture up to the surface where food is more plentiful.

And when they head up top (or back down) the hum -- about 3 to 6 decibels louder than ocean background noise -- kicks in.

“It’s not that loud,” Baumann-Pickering said in a statement. “It sounds like a buzzing or humming, and that goes on for an hour to two hours, depending on the day.” (Check out a sound clip of the humming here.)

The purpose behind the sound is still an open question. Baumann-Pickering said it could be a signal to the entire group to head up to the surface or back down.

While it’s neat to think that such communication could be happening among the animals, there could also be a less high-minded reason for the hum. It turns out the creatures might just be passing gas, as their swim bladders regulate their buoyancy.

“It’s known that some fish are considered to be farting,” Baumann-Pickering told NPR, “that they emit gas as they change depths in the water column.”

Read more at Discovery News

Beaten-Up Dinosaur Lived Through Intense Pain

A carnivorous dinosaur from Arizona suffered from “record-breaking pain,” according to a new study that looked at the animal’s remains.

The dinosaur, Dilophosaurus wetherilli, lived about 193 million years ago and shows evidence of having survived the largest number of broken forelimb bones in any known meat-eating dino. The findings are published in the journal PLOS ONE.

“It is not possible to determine with certainty the number of traumatic events that this plethora of pathological features represents,” co-authors Phil Senter of Fayetteville State University and Sara Juengst of Appalachian State University wrote. “It is possible that the entire array of fractures and punctures is the result of a single, high-energy encounter.”

For example, the authors say the dinosaur’s fractures may have occurred when the animal was smashed into a tree or rock face during a fight. It also had puncture wounds that may have been inflicted by its foe’s claws during the same encounter. The authors say it’s at least certain the animal survived its traumatic encounter since they could detect a high level of healing at its wound sites.

Senter and Juengst analyzed the remains of the dinosaur, which once measured about 20 feet long and weighed around 1100 pounds. The fossils were found in the Arizona’s Kayenta Formation that is spread across the Colorado Plateau.

The researchers believe signs of healing indicate the dinosaur “survived for months and possibly years after its ailments began, but its right third finger was permanently deformed and lacked the capability” of flexing.

Some of the deformities might have been due to a condition known as “developmental osteodysplasia,” which afflicts some modern birds. This is an abnormality in the way that bone develops. The affliction, combined with one or more traumatic events, could explain what happened to the victim.

The scientists suspect that life was incredibly challenging for the dinosaur, after the bone problems occurred.

Read more at Discovery News

Dodo Birds Not So Dumb After All

Dodos weren’t as dumb as their reputation suggests. New research finds that these extinct, flightless birds were likely as smart as modern pigeons, and had a better sense of smell.

Dodos (Raphus cucullatus) had gone extinct by 1662, less than 100 years after their island home of Mauritius became a destination for Dutch explorers. The birds, unfamiliar with humans, were initially fearless. This made them easy pickings for hunters and also cemented their reputation as dullards.

A new computed tomography (CT) scan of a rare, intact dodo skull reveals that these birds had brain-to-body sizes that are similar to those of modern pigeons.

“It’s not impressively large or impressively small — it’s exactly the size you would predict it to be for its body size,” study researcher Eugenia Gold of Stony Brook University said in a statement, referring to the dodo’s brain. “So if you take brain size as a proxy for intelligence, dodos probably had a similar intelligence level to pigeons.”

And pigeons aren’t that dumb. Studies find that they’re capable of recognizing and remembering human faces. They’re also very trainable and have mathematical abilities similar to those of rhesus monkeys.

Gold, an anatomist, was interested in learning more about the dodo’s ecology, as this bird is mostly known through the contemporaneous accounts of the sailors and settlers who brought about the animal’s demise. A few living dodos were brought back to Europe, she and her colleagues wrote today (Feb. 23) in the Zoological Journal of the Linnean Society. But those animals were kept confined and fed human food, making them fat. Wild dodos may not have looked like the portly birds seen in European illustrations.

Gold and her colleagues conducted a CT scan of the dodo skull, which was at the Natural History Museum, London. They also scanned the skull of the dodo’s closest relative, the Rodrigues solitaire (Pezophaps solitaria). This flightless bird lived on the Indian Ocean island of Rodrigues and went extinct in the 1700s, due to overhunting and other human activities. Using the scans, the researchers then reconstructed virtual “casts” of the bird brains.

Read more at Discovery News

Gravitational Wave Black Holes Born From One Star?

The pair of black holes the set off the first detection of gravitational waves through space may have been spawned by the death of a single, massive star.

“It’s the cosmic equivalent of a pregnant woman carrying twins,” astrophysicist Avi Loeb, with the Harvard-Smithsonian Center for Astrophysics, said in a statement.

Scientists believe that when a massive star explodes, its core collapses into a black hole, which is a region so dense with matter that not even photons of light can escape from the gravitational warping of space and time.

Scientists detected a gamma ray flash on Sept. 14, 2015, just a fraction of a second after the Laser Interferometer Gravitational-wave Observatory (LIGO) picked up the first signals of gravitational waves, caused in this case by the merger of two black holes.

Gravitational waves are similar to electromagnetic radiation, such as radio, visible, light and X-rays, except that it is space itself that is waving.

Loeb believes that that gamma ray burst may be a clue that the black holes seen by LIGO were twins, born out of the destruction of a single star.

He theorizes that if the star was spinning very fast, the core may have been stretched into a dumbbell shape, and then separated into two sections, each forming a black hole.

“In order to power both the gravitational wave event and the gamma-ray burst, the twin black holes must have been born close together, with an initial separation of order the size of the Earth, and merged within minutes. The newly formed single black hole then fed on the in-falling matter, consuming up to a sun’s worth of material every second and powering jets of matter that blasted outward to create the burst,” the Harvard-Smithsonian Center for Astrophysics said in a statement.

NASA’s Fermi Gamma-ray Space Telescope discovered the gamma burst just 0.4 seconds after the LIGO gravitational waves’ detection, the center said. Both events came from the same general area of the sky.

Read more at Discovery News

Stunning Survey Reveals Our Mesmerizing Milky Way

They say a picture is worth a thousand words, but this picture is worth tens of billions of stars.

And that’s what we are seeing here; this is the plane of our galaxy, seen through the eyes of a powerful telescope called the Atacama Pathfinder EXperiment telescope (APEX), located high on the Chajnantor Plateau in Chile’s Atacama region and managed by the European Southern Observatory (ESO).

The mosaic of images represents the completion of the APEX Telescope Large Area Survey of the Galaxy (ATLASGAL) project that imaged the entirety of the Milky Way’s plane seen edge-on from APEX’s Southern Hemisphere location. It is the first galactic survey in sub-millimeter wavelengths — a region of the electromagnetic spectrum between infrared and radio waves — and because of the telescope’s awesome 12-meter wide aperture, astronomers can reveal far more detail in these observations than even space-based telescopes.

Sub-millimeter wavelengths are important to astronomers as they are generated by gas and dust only a few tens of degrees above absolute zero. Seeing our galaxy in these wavelengths can help us better understand the distribution of interstellar gas clouds that ultimately provide fuel for baby stars.

“ATLASGAL provides exciting insights into where the next generation of high-mass stars and clusters form,” said Timea Csengeri from the Max Planck Institute for Radio Astronomy (MPIfR), Bonn, Germany, in an ESO news release. “By combining these with observations from Planck, we can now obtain a link to the large-scale structures of giant molecular clouds.”

In a selection of release images, ATLASGAL is compared with data from the European Planck space observatory, surveys in visible light and views from NASA’s Spitzer Space Telescope, which sees the universe in infrared.

From Discovery News

Rattlesnake Colony Planned for Uninhabited Island

Conservationists in Massachusetts plan to establish a population of native venomous timber rattlesnakes on an uninhabited island, according to the state’s Division of Fisheries and Wildlife (MassWildlife).

Locals are so alarmed by the idea that officials are holding a public meeting on Tuesday to present their case and address concerns.

“Not only has the timber rattlesnake declined in Massachusetts and throughout New England, it is now completely extirpated from Maine and Rhode Island,” according to the MassWildlife statement. “Humans are the greatest threat to (the) timber rattlesnake. In Massachusetts, the timber rattlesnake has lived continuously since long before European settlement, and has persisted in the face of sometimes intense persecution, but its decline over the past 30 years has been more severe than (at) any other time in history.”

Tom French, assistant director of MassWildlife’s Natural Heritage and Endangered Species program, and his colleagues propose to establish a small group of the rattlesnakes on Mount Zion, which is a large island closed to public access at the Quabbin Reservoir located in central Massachusetts. The reservoir is owned and managed by the Department of Conservation and Recreation’s Division of Water Supply Protection.

The plan is to raise juvenile snakes from Massachusetts in captivity by the Roger Williams Zoo in Providence, R.I. After about two years they grow to a size that deters predators, and the young snakes would then be released on the island. French and his team say that only between one and 10 of the timber rattlesnakes would be released in any given year.

To ease worried minds, they reminded that “in the southern Appalachians, a healthy rattlesnake population may be as high as 150 individuals, however here in Massachusetts, our populations are generally much smaller.”

Many locals, however, are not eagerly embracing the plan just yet. Peter Mallett, president of the Millers River Fishermen’s Association, was asked by the Boston Globe, “What could go wrong?” He replied: “Well, they swim.”

MassWildlife countered with this explanation: “While rattlesnakes are perfectly good swimmers, their survival depends on access to unusually deep hibernation sites, usually in a rock talus or boulder field below a ledge, or a deep fissure in bedrock. These special habitats are scarce on our landscape. Any snake that leaves the island whether by water or over the causeway will not be able to find a suitable hibernation site and if unable to return will die over the winter.”

Read more at Discovery News