Paleontology: Aftermath of a mass extinction

A specimen of the newly identified fossil species Ticinolepis crassidens (above) and of the species Ticinolepis longaeva.

A new study of fossil fishes from Middle Triassic sediments on the shores of Lake Lugano provides new insights into the recovery of biodiversity following the great mass extinction event at the Permo-Triassic boundary 240 million years ago.

The largest episode of mass extinction in the history of the Earth, which led to the demise of about 90% of marine organisms and a majority of terrestrial species, took place between the Late Permian and Early Triassic, around 240 million years ago. How long it took for biological communities to recover from such a catastrophic loss of biodiversity remains the subject of controversial debate among paleontologists. A new study of fossil fishes from Middle Triassic strata on the shores of Lake Lugano throws new light on the issue.

The study, undertaken by researchers led by Dr. Adriana López-Arbarello, who is a member of the GeoBiocenter at Ludwig-Maximilians-Universitaet (LMU) in Munich and the Bavarian State Collection for Paleontology and Geology, suggests that the process of recovery was well underway within a few million years. The authors, including Dr. Heinz Furrer of Zurich University and Dr. Rudolf Stockar of the Museo Cantonale di Storia Naturale in Lugano, who led the excavations at the sites, and Dr. Toni Bürgin of the Naturmuseum St. Gallen report their findings in the journal PeerJ.

The fossil fishes analyzed by López-Arbarello and her colleagues originate from Monte San Giorgio in the canton Ticino in Switzerland, which is one of the most important sources of marine fossils from the Middle Triassic in the world. The Monte San Giorgio rises to an altitude of 1000 m on the promontory that separates the southern arms of Lake Lugano in the Southern Swiss Alps. But in the Middle Triassic, it was part of a shallow basin dotted with islands fringed by lagoons, which were separated by reefs from the open sea. "

The particular significance of its fossil fauna lies in the careful stratigraphic work that has accompanied the excavations here. The positions of each of the fossil finds discovered here have been documented to the centimeter," says Adriana López-Arbarello. On the basis of detailed anatomical studies of new material and a taxonomic re-evaluation of previously known specimens from the locality, she and her colleagues have identified a new genus of fossil neopterygians, which they name Ticinolepis. The Neopterygii include the teleost fishes, which account for more than half of all extant vertebrate species. However, the new fossil species are assigned to the second major group of neopterygians, the Holostei, of which only a handful of species survives today. The researchers assign two new fossil species to the genus Ticinolepis, namely T. longaeva and T. crassidens, which occur in different sedimentary beds within the so-called Besano Formation on Monte San Giorgio.

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Ancient rocks reveal how Earth recovered from mass extinction

Analysis of rocks unearthed in Oman that were formed in an ancient ocean around the time of Earth's greatest mass extinction have helped explain why life on Earth took so long to recover.

Scientists have shed light on why life on Earth took millions of years to recover from the greatest mass extinction of all time.

The study provides fresh insight into how Earth's oceans became starved of oxygen in the wake of the event 252 million years ago, delaying the recovery of life by five million years.

Findings from the study are helping scientists to better understand how environmental change can have disastrous consequences for life on Earth.

The Permian-Triassic Boundary extinction wiped out more than 90 per cent of marine life and around two thirds of animals living on land. During the recovery period, Earth's oceans became starved of oxygen -- conditions known as anoxia.

Previous research suggested the mass extinction and delayed recovery were linked to the presence of anoxic waters that also contained high levels of harmful compounds known as sulphides.

However, researchers say anoxic conditions at the time were more complex, and that this toxic, sulphide-rich state was not present throughout all the world's oceans.

The team, led by researchers at the University of Edinburgh, used precise chemical techniques to analyse rocks unearthed in Oman that were formed in an ancient ocean around the time of the extinction.

Data from six sampling sites, spanning shallow regions to the deeper ocean, reveal that while the water was lacking in oxygen, toxic sulphide was not present. Instead, the waters were rich in iron.

The finding suggests that iron-rich, low oxygen waters were a major cause of the delayed recovery of marine life following the mass extinction.

The study also shows how oxygen levels varied at different depths in the ocean. While low oxygen levels were present at some depths and restricted the recovery of marine life, shallower waters contained oxygen for short periods, briefly supporting diverse forms of life.

The precise cause of the long recovery period remains unclear, but increased run-off from erosion of rocks on land -- caused by high global temperatures -- likely triggered anoxic conditions in the oceans, researchers say.

The study, published in the journal Nature Communications, was funded by the Natural Environment Research Council and the International Centre for Carbonate Reservoirs. The work is a contribution to the UNESCO International Geoscience Programme. It was carried out in collaboration with the Universities of Leeds, Gratz, Bremen and Vienna University.

Dr Matthew Clarkson, of the University of Edinburgh's School of GeoSciences, who led the study, said: "We knew that lack of oxygen in the oceans played a key role in the extinction and recovery processes, but we are still discovering how exactly it was involved. Our findings about the chemistry of the ocean at the time provide us with a clearer picture of how this complex process delayed the recovery of life for so long."

Read more at Science Daily

Ozone Layer Protections Actually Warmed the Planet

Back in 1987, 60 countries signed the Montreal Protocol, a landmark agreement to phase out gases called chlorofluorocarbons, or CFCs, which were used in refrigerators, air conditioners, and aerosol cans, because they were eroding the atmospheric ozone layer that protects us against getting too much solar radiation.

Unfortunately, this caused a big problem that no one foresaw at the time. The hydrofluorocarbons (HFCs) that replaced the CFCs in those devices didn't hurt the ozone layer. But HFCs were potent greenhouse gases that contributed disproportionately to global warming, which wasn't getting as much attention as it is now.

That's why diplomats and officials from various countries have assembled in Vienna this week to amend the Montreal Protocol and phase out HFCs, which are vastly more powerful than carbon dioxide when it comes to greenhouse effects.

The Institute for Sustainable Development says that HFCs are 1,300 times more potent than a similar quantity of C02, when it comes to warming the planet. A 2015 article published in the Journal of Geophysical Research Atmospheres reported that by 2050, one particular type of HFC, HFC-134a, could add as much as 19 percent to the warming effect of carbon dioxide.

Veerabhadran Ramanathan, a climate scientist at the Scripps Institution of Oceanography, told the Washington Post that "by banning HFCs, you prevent another disaster downstream."

Another expert, former Clinton Administration climate change adviser Paul Bledsoe, said such a ban would reduce global warming in the 21st Century by 0.9 degrees Fahrenheit.

The U.S. Environmental Protection Agency already has approved several alternative refrigerants that could be used to replace HFCs.

From Discovery News

2 Newfound Alien Planets Could Support Life

NASA's Kepler space telescope recently discovered 104 exoplanets, including four possibly rocky worlds that circle a red dwarf star called K2-72.

NASA's Kepler space telescope has spotted four possibly rocky alien planets orbiting the same star, and two of these newfound worlds might be capable of supporting life.

The four exoplanets circle a red dwarf — a star smaller and dimmer than the sun — called K2-72, which lies 181 light-years from Earth in the Aquarius constellation. All four worlds are between 20 percent and 50 percent wider than Earth, making them good candidates to be rocky, discovery team members said.

Two of the four planets, known as K2-72c and K2-72e, appear to be in the star's "habitable zone" — that just-right range of distances at which liquid water can exist on a world's surface, the scientists added.

Because K2-72 is a red dwarf, its habitable zone is much closer in than that of the sun. For example, K2-72c completes one orbit every 15 Earth days, yet it is likely just 10 percent warmer than our planet. K2-72e has a 24-Earth-day year, and it's about 6 percent colder than Earth, the scientists said. (All four newfound planets complete an orbit in 24 Earth days or less, making them closer to K2-72 than Mercury is to the sun.)

The K2-72 planets are among 104 alien worlds recently discovered by the Kepler telescope during its bounce-back K2 mission. Study leader Ian Crossfield, of the University of Arizona's Lunar and Planetary Laboratory, first announced this haul in January, during a presentation at the 227th Meeting of the American Astronomical Society in Kissimmee, Florida, and the results were just published online in The Astrophysical Journal Supplement Series.

Kepler finds alien planets by noticing the tiny brightness dips they cause when they cross their host stars' faces from the spacecraft's perspective. This work requires incredibly precise pointing — an ability Kepler lost in May 2013 when the second of its four orientation-maintaining reaction wheels failed.

However, Kepler team members soon figured out a way to stabilize the telescope using sunlight pressure and the two remaining reaction wheels. In 2014, Kepler embarked on a new mission called K2, during which it is observing a variety of cosmic objects and phenomena, including exoplanets.

But Kepler's planet hunt is quite different this time around. Whereas the observatory stared continuously at one small patch of sky during its original mission, Kepler is now peering at different regions during a series of 80-day "campaigns."

Read more at Discovery News

A glimpse inside the atom

Atomic orbitals of carbon atoms in graphene.

An electron microscope can't just snap a photo like a mobile phone camera can. The ability of an electron microscope to image a structure -- and how successful this imaging will be -- depends on how well you understand the structure. Complex physics calculations are often needed to make full use of the potential of electron microscopy. An international research team led by TU Wien's Prof. Peter Schattschneider set out to analyse the opportunities offered by EFTEM, that is energy-filtered transmission electron microscopy. The team demonstrated numerically that under certain conditions, it is possible to obtain clear images of the orbital of each individual electron within an atom. Electron microscopy can therefore be used to penetrate down to the subatomic level -- experiments in this area are already planned. The study has now been published in the physics journal Physical Review Letters.

In search of the electron orbital

We often think of atomic electrons as little spheres that circle around the nucleus of the atom like tiny planets around a sun. This image is barely reflected in reality, however. The laws of quantum physics state that the position of an electron cannot be clearly defined at any given point in time. The electron is effectively smeared across an area close to the nucleus. The area that could contain the electron is called the orbital. Although it has been possible to calculate the shape of these orbitals for a long time, efforts to image them with electron microscopes have been unsuccessful to date.

"We have calculated how we might have a chance of visualising orbitals with an electron microscope," says Stefan Löffler from the University Service Centre for Transmission Electron Microscopy (USTEM) at TU Wien. "Graphene, which is made of just one single layer of carbon atoms, is an excellent candidate for this task. The electron ray is able to pass easily through the graphene with hardly any elastic scattering. An image of the graphene structure can be created with these electrons."

Researchers have been aware of the principle of "energy-filtered transmission electron microscopy" (EFTEM) for some time. EFTEM can be used to create quite specific visualisations of certain kinds of atoms whilst blocking out the others. For this reason, it is often used today to analyse the chemical composition of microscopic samples. "The electrons shot through the sample can excite the sample's atoms," explains Stefan Löffler. "This costs energy, so when the electrons emerging emerge from the sample, they are slower than when they entered it. This velocity and energy change is characteristic for certain excitations of electron orbitals within the sample."

After the electrons have passed through the sample, a magnetic field sorts the electrons by energy. "A filter is used to block out electrons that aren't of interest: the recorded image contains only those electrons that carry the desired information."

Defects can be helpful

The team used simulations to investigate how this technique could help reach a turning point in the study of electron orbitals. While doing so, they discovered something that actually facilitated the imaging of individual orbitals: "The symmetry of the graphene has to be broken," says Stefan. "If, for instance, there is a hole in the graphene structure, the atoms right beside this hole have a slightly different electronic structure, making it possible to image the orbitals of these atoms. The same thing can happen if a nitrogen atom rather than a carbon atom is found somewhere in the graphene. When doing this, it's important to focus on the electrons found within a narrow and precise energy window, minimise certain aberrations of the electromagnetic lens and, last but not least, use a first-rate electron microscope." All of these issues can be overcome, however, as the research group's calculations show.

Read more at Science Daily

New discoveries about photosynthesis may lead to solar cells of the future

For the first time, researchers have successfully measured in detail the flow of solar energy, in and between different parts of a photosynthetic organism. The result is a first step in research that could ultimately contribute to the development of technologies that use solar energy far more efficiently than what is currently possible.

For about 80 years, researchers have known that photochemical reactions inside an organism do not occur in the same place as where it absorbs sunlight. What has not been known, however, is how and along what routes the solar energy is transported into the photosynthetic organism -- until now.

"Not even the best solar cells that we as humans are capable of producing can be compared to what nature performs in the first stages of energy conversion. That is why new knowledge about photosynthesis will become useful for the development of future solar technologies," says Donatas Zigmantas, Faculty of Science at Lund University, Sweden.

Together with his colleagues Jakub Dostál, Lund University, and Jakub Pšenčík, Charles University in Prague, Donatas Zigmantas has studied the photosynthesis of bacterial cells. Using ultrafast spectroscopy -- a measurement method that uses light to study molecules etc. -- they were able to locate the routes along which solar energy is transported. The routes run both within and between the components of a photosynthetic cell. According to the researchers, their discovery demonstrates how the biological machinery is connected.

The research results show that the transport of solar energy is much more efficient within, than between, different cell components. It limits the transfer of energy between the components and thereby also the efficiency of the entire photosynthetic energy conversion process.

"We have identified the transport routes as well as the bottlenecks that cause congestion in the photosynthetic energy conversion. In the future, this knowledge can be used within solar cell technology," says Donatas Zigmantas.

So far this is basic research -- more studies of how energy is transported in both natural and artificial systems are needed before the results can be turned into practice.

Read more at Science Daily

Researchers build a crawling robot from sea slug parts and a 3-D printed body

A sea slug's buccal I2 muscle powers this biohybrid robot as it crawls like a sea turtle. The body and arms are made from a 3-D printed polymer.

Researchers at Case Western Reserve University have combined tissues from a sea slug with flexible 3-D printed components to build "biohybrid" robots that crawl like sea turtles on the beach.

A muscle from the slug's mouth provides the movement, which is currently controlled by an external electrical field. However, future iterations of the device will include ganglia, bundles of neurons and nerves that normally conduct signals to the muscle as the slug feeds, as an organic controller.

The researchers also manipulated collagen from the slug's skin to build an organic scaffold to be tested in new versions of the robot.

In the future, swarms of biohybrid robots could be released for such tasks as locating the source of a toxic leak in a pond that would send animals fleeing, the scientists say. Or they could search the ocean floor for a black box flight data recorder, a potentially long process that may leave current robots stilled with dead batteries.

"We're building a living machine -- a biohybrid robot that's not completely organic -- yet," said Victoria Webster, a PhD student who is leading the research. Webster will discuss mining the sea slug for materials and constructing the hybrid, which is a little under 2 inches long, at the Living Machines conference in Edinburgh, Scotland, this week.

Webster worked with Roger Quinn, the Arthur P. Armington Professor of Engineering and director of Case Western Reserve's Biologically Inspired Robotics Laboratory; Hillel Chiel, a biology professor who has studied the California sea slug for decades; Ozan Akkus, professor of mechanical and aerospace engineering and director of the CWRU Tissue Fabrication and Mechanobiology Lab; Umut Gurkan, head of the CWRU Biomanufacturing and Microfabrication Laboratory, undergraduate researchers Emma L. Hawley and Jill M. Patel and recent master's graduate Katherine J. Chapin

By combining materials from the California sea slug, Aplysia californica, with three-dimensional printed parts, "we're creating a robot that can manage different tasks than an animal or a purely manmade robot could," Quinn said.

The researchers chose the sea slug because the animal is durable down to its cells, withstanding substantial changes in temperature, salinity and more as Pacific Ocean tides shift its environment between deep water and shallow pools. Compared to mammal and bird muscles, which require strictly controlled environments to operate, the slug's are much more adaptable.

For the searching tasks, "we want the robots to be compliant, to interact with the environment," Webster said. "One of the problems with traditional robotics, especially on the small scale, is that actuators -- the units that provide movement -- tend to be rigid."

Muscle cells are compliant and also carry their own fuel source -- nutrients in the medium around them. Because they're soft, they're safer for operations than nuts-and-bolts actuators and have a much higher power-to-weight ratio, Webster said.

The researchers originally tried using muscle cells but changed to using the entire I2 muscle from the mouth area, or buccal mass. "The muscle already had the optimal structure and form to provide the function and strength needed," Chiel said.

Akkus said, "When we integrate the muscle with its natural biological structure, it's hundreds to 1,000 times better."

In their first robots, the buccal muscle, which naturally has two "arms," is connected to the robots printed polymer arms and body. The robot moves when the buccal muscle contracts and releases, swinging the arms back and forth. In early testing, the bot pulled itself about 0.4 centimeters per minute.

To control movement, the scientists are turning to the animal's own ganglia. They can use either chemical or electrical stimuli to induce the nerves to contract the muscle.

"With the ganglia, the muscle is capable of much more complex movement, compared to using a manmade control, and it's capable of learning," Webster said.

The team hopes to train ganglia to move the robot forward in response to one signal and backward in response to a second.

With the goal of making a completely organic robot, Akkus' lab gelled collagen from the slug's skin and also used electrical currents to align and compact collagen threads together, to build a lightweight, flexible, yet strong scaffold.

Read more at Science Daily

2,000-Year-Old Dog Graveyard Found in Siberia

Archaeologists have discovered a prehistoric dog graveyard at a 2,000-year-old village near the Arctic Circle in Russia's Siberia.

The carefully buried remains of five dogs were recently found in a 2,000-year-old doggy graveyard near the Arctic Circle in Siberia, according to archaeologists.

This discovery at the Ust-Polui archaeological site, in Salekhard, Russia, reveals close relationships between the region's people and their animal "best friends" two millennia B.C. The dogs likely served as pets, workers and sources of food — and possibly as sacrificial offerings in religious ceremonies, the researchers said.

"The role of dogs at Ust-Polui is really complex and variable," Robert Losey, an archaeologist at the University of Alberta in Canada, wrote in an email to Live Science from Salekhard, where he is carrying out fieldwork at Ust-Polui.

"The most striking thing is that the dog remains are really abundant compared to all other sites in the Arctic — there are over 115 dogs represented at the site," Losey said. "Typically, sites have only a few dog remains — 10 at most."

The dogs were likely involved in various tasks in the ancient Arctic village, including pulling sleds, he said. The remains of two sleds, as well as a carved bone knife handle thought to depict a sled dog in a harness, have been found at the site.

"Some [dogs] were probably also used in hunting, for reindeer and birds, the remains of which were both abundant at the site," Losey said.

Parts of a reindeer harness had also been found at Ust-Polui, he added, and dogs may have been used to herd reindeer, as is still done today by some communities in the region.

But despite evidence that the dogs worked with people and other animals, it was also clear that many of the dogs at Ust-Polui had been butchered and probably eaten, Losey said. Many of the dog bones had cut marks on them, and were found scattered around the site in the same way as the bones of other food animals, such as deer and birds, he said.

Some of the dog consumption may have been related to sacrifices or rituals, or even feasting, Losey noted. In fact, "at one place in the site, the heads of 15 dogs were piled together, all with their brain cases broken open in the same manner," he said.

He added that the sacrificing of dogs was well documented among indigenous people in this region of Siberia, "and is done to appease spirits, or to ensure community health, and so on."

But though it might have been a dog's life for most of the canine population of Ust-Polui, a few top dogs seem to have enjoyed special treatment, the archaeologists said.

Of the more than 115 dogs that archaeologists identified among the animal bones at Ust-Polui, the remains of just five dogs were found carefully buried in a group near one edge of the site, Losey said.

This separation likely indicates close bonds between some people and some dogs in the ancient village, he said.

Each of the prehistoric doggy graves contained the entire dog skeleton, laid on its side in a shallow pit, similar to three human burials at the site, and they showed no signs of butchery or of being intentionally killed, the researchers found.

"The only thing that distinguishes them from the human burials is their location. No other animals at Ust-Polui were treated like this," Losey said.

Losey started working with the dog remains from Ust-Polui three years ago, as part of his work studying the ancient relationships between people and dogs in the world's northern regions.

Read more at Discovery News

Health benefits of Pokémon Go

Pokémon Go being played.

Do you want to be the very best, like no one ever was? Real-life positive health consequences of playing Pokémon Go -- a new GPS-based augmented reality game -- are happening across the nation. According to Matt Hoffman, DNP, clinical assistant professor at the Texas A&M College of Nursing, this quest to "catch 'em all" is great news for public health.

I will travel across the land, searching far and wide

Players, known as "trainers," download the Pokémon Go game to their smartphones. To progress in the game, trainers must walk around to find and catch Pokémon and access specific locations called Pokéstops -- where Pokéballs and other useful items are collected. Poké eggs are among the things that can be collected at these locations. Getting to Pokéstops, catching different Pokémon and hatching the Poké eggs requires walking; lots of walking.

"Playing the game is a lot of fun, and it has been a catalyst to get people moving," said Hoffman who has been affectionately dubbed the "Pokémon Professor" by co-workers.

"What began as just playing the game has now become a hobby for me that provides certain health benefits," Hoffman continued. "I've spent an hour or two at a time venturing around the community to find Pokéstops. And, to hatch one egg, a trainer must walk anywhere from one to six miles. There's no doubt about it, I am exercising more as a result of playing the game, and I am enjoying it."

Hoffman isn't alone. Estimates of the number of Pokémon Go daily users range from nine to 21 million people, and this user base is growing daily. In addition to inspiring exercise, playing Pokémon Go may have additional benefits.

Pokémon, (gotta catch'em all!) it's you and me

"There is a sense of community when trainers converge in search of Pokémon, or when they gather together at Pokéstops," Hoffman said. "The game is bringing people together, providing opportunity for social interaction and increasing our sense of belonging, which can have a positive impact on our emotional and mental health."

Additionally, families may find that Pokémon Go lessens the technology tension that divides the generations. "This is a relatively non-violent game, and I have seen families walking around playing the game together," Hoffman said. "Or, it encourages parents to go outside with their children while they play. Pokémon Go has the ability to transport families away from an evening on the couch to walking around the neighborhood."

You teach me and I'll teach you

Hoffman said playing the game has even broadened his sense of curiosity and knowledge about his local community. "I discovered new experiences within my community because the game has led me to areas that I haven't explored, or, previously only driven through," he said. "Additionally, I've met many interesting people while playing the game, and I enjoy seeing the variation in the character designs and abilities."

Come with me, the time is right, there's no better team

Multiply the number of Pokémon Go players by the number of kilometers they must travel to progress in the game, and the chances of negative consequences increase. "We often hear of people falling off curbs or sustaining injuries as a result of staring at their phones and not paying attention to their surroundings," Hoffman said. "It's good to always keep safety and best practices in mind."

Hoffman emphasized players watch where they walk and be aware of surroundings when playing. There is safety in numbers, and he encourages playing with friends as a team.

Read more at Science Daily

Victim's Ghost Seen in Accident Photo? Unlikely

A photo taken at the scene of a fatal motorcycle crash in Kentucky has gone viral this week, with many claiming they can see the accident victim's spirit leaving his body.

The image, showing what seems to be a gray or white vertical form in the air above two ambulances, was photographed and shared on social media by Kentucky resident Saul Vazquez.

"I pulled over roll the passenger side window and snap the picture," Mr. Vazquez posted on his Facebook post of the photo, which as of today has nearly 9,000 shares.

A People magazine online article was headlined "Photo of Fatal Accident Become Online Sensation Over Claims It Shows Victim's Spirit." Others have suggested it's not a spirit but instead an angel. Stories of miracles or seemingly supernatural events at the scene of accidents are not uncommon; last year police officers who helped rescue a baby from an overturned car in a Utah river claimed that they heard an unexplained voice calling from the car—despite the fact that the mother had been dead for hours.

There are several reasons to suspect that the image may not be paranormal, but the best (and most obvious) reason to doubt that the whitish blur is the spirit of the accident victim appears in the news story about the incident: "He [the motorcylist] was transported to the hospital where he later died." Since the motorcyclist wasn't dead when the photo was taken, it would seem very unlikely that his spirit would be leaving his body at that time.

If spirits (or angels) can be photographed at scenes of tragic accidents—especially those involving many victims—then they should appear regularly. News photos and video of train, plane, and bus accidents, for example, should reveal ghostly images in and around the wreckage. In fact, if the soul leaves the body at death (as theology and ghost folklore suggest), then hospitals—not graveyards nor haunted houses—should be filled with ghosts and blurry white images in the hallways and emergency rooms.

The idea that the soul can somehow be quantified or recorded at the time of death goes back over a century. The most famous scientific experiment on that topic was conducted by Dr. Duncan MacDougall, who in 1907 tried to measure the weight of the soul. He weighed a half-dozen terminally ill patients before, during, and after death, concluding that there was an average of 21 grams difference in the weight of the bodies before and after death. His experiments were badly designed, however, with a tiny sample size and crude measurement tools. More modern measurements find no such effect, though the myth that the human soul weighs 21 grams remains today.

So if the vertical whitish thing in the photo isn't a ghost, what is it?

Vazquez has denied that the image has been altered, and there's no reason to think it has. It's much more likely to be an ordinary object that has taken on a spooky context because of the circumstances; in other words that same photo could likely have been taken at that same spot a day earlier, and no one would have associated it with anything odd or tragic.

Writer Hemant Mehta offered the following explanation on his blog: "It could easily be a discolored tree trunk. Seriously. I pulled up a Google Maps image of Highway 15 near Stanton, Kentucky where the accident took place. I don't know if this is the exact spot, but it was *very* easy to find a discolored tree trunk in the image."

It's difficult to tell what exactly the image is, but the image shows other foliage emerging from the shade of the trees in the same area; a tree trunk or light-colored branch is a real possibility. It could also be smoke from the wreck, though the motorcycle seems to be off to one side.

In any event, it's noteworthy that apparently no one at the scene reported seeing anything unusual, nor the supposed apparition just above them.

Read more at Discovery News