Skin-ditching gecko inexplicably leaves body armor behind when threatened

Fish-scale geckos shed their skin when threatened. But CT scans reveal bony deposits -- essentially body armor -- in their scales, raising the question of why the geckos seem to have conflicting defense strategies.

When trouble looms, the fish-scale geckos of Madagascar resort to what might seem like an extreme form of self-defense -- tearing out of their own skin.

Their unusually large, overlapping scales flake off so easily that one biologist in the late 1800s tried collecting the geckos with cotton, but even with careful handling, few fish-scale gecko specimens have been preserved with all scales intact.

Now, new research published in the African Journal of Herpetology shows the geckos' fragile skin contains a hidden strength. Inside the scales are bony deposits known as osteoderms, the same material that makes up the tough scales and plates of crocodilians and armadillos. But the presence of osteoderms in fish-scale geckos raises a herpetological mystery: If they have armor, why do they discard it?

"The big question is why there are these conflicting defense strategies," said Daniel Paluh, the study's lead author and a doctoral student at the Florida Museum of Natural History. "This gecko can actually drop its skin as a defense mechanism, but it also has these mineralizations -- usually thought of as body armor -- that it's just leaving behind."

As part of his research as a master's student at Villanova University, Paluh studied hundreds of geckos using computed tomography (CT) technology, which uses thousands of X-rays to create high-resolution, multilayered 3-D images of specimens. The CT scan of Geckolepis maculata, a species in the fish-scale genus, revealed dense bony material inside the skin, a feature Paluh had not noticed in most other geckos.

"I thought, 'Wow, this is really strange,' " he said. "We started diving deeper to verify that what we were seeing in the CT scan were actually these mineralized elements."

Osteoderms are found in some lizards, but they are rare in geckos, a group that includes more than 1,600 species. Prior to Paluh's study, only the genus Tarentola, or wall geckos, and Gekko gecko, the tokay gecko, were known to have this protective outer armor.

Most geckos have thin skin covered in tiny, granular scales and tend to rely on camouflage and the cover of night to hide from predators, Paluh said.

Some groups, such as Geckolepis, have also evolved weak skin as a form of defense, said Aaron Bauer, the Gerald M. Lemole Endowed Chair in Integrative Biology at Villanova University and co-author of the study. When a predator strikes, these geckos can rip out of their skin to escape, "like the tear-away football jerseys of the 1970s," he said.

The apparent paradox of "sheddable armor" contributed to the widespread questioning of a paper by biologist W.J. Schmidt, who in 1911 published his observations of osteoderms in the scales of Geckolepis polyepis. His findings were met with skepticism for decades until Paluh's CT scan proved Schmidt was right.

"Schmidt had to illustrate what he saw, which could have contributed to his work being questioned," Paluh said. "It was unclear whether he was replicating the histology accurately. The advantage we have today is that we can combine newer, innovative tools with traditional methods than have been used for hundreds of years. It provides a new perspective to some of the classical anatomical observations."

To verify the presence of osteoderms in G. maculata, Paluh used techniques similar to Schmidt's. He cleared and stained excised patches of skin containing multiple scales to determine if the tissue was mineralized. Removing the skin revealed tiny, interlocking osteoderms similar to those Schmidt described and illustrated more than a century earlier.

"Schmidt was a great anatomist, and I'm sure that he was confident in what he saw," Bauer said. "Indeed, anatomists of his time, working with much less technically advanced equipment than we have today, were pretty good about getting animal anatomy right."

Paluh said osteoderms might not necessarily serve as a defensive shield. They could contribute calcium for egg development in female geckos or help regulate body temperature.

The researchers hypothesize that osteoderms likely evolved independently in Geckolepis, Tarentola and Gekko gecko. The geckos are not close relatives, and CT scans showed osteoderm structure and density vary among the three. G. gecko and Tarentola mauritanica have plate-like and granular osteoderms, while in G. maculata, the deposits resemble the small irregular pieces of a mosaic.

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Origin of human genus may have occurred by chance

Archaeological excavation

An often cited claim that humans, who are smarter and more technologically advanced than their ancestors, originated in response to climate change is challenged in a new report by a Center for the Advanced Study of Human Paleobiology researcher at George Washington University.

Many scientists have argued that an influx, described as a "pulse," of new animal species appear in the African fossil record between 2.8 and 2.5 million years ago, including our own genus Homo. Experts believe it takes a broad-scale event like global climate change to spark the origination of so many diverse new species. However, W. Andrew Barr, a visiting assistant professor of anthropology, published a report that says it's possible the pulse of new species could have occurred by chance and might not be directly related to climate change.

It is generally accepted that when major environmental changes occur, some species will go extinct and others will originate, which can create a cluster or pulse of new species in the fossil record. However, there is not a set definition of what is considered a pulse, so experts have disagreed about which clusters constitute meaningful events and which can be explained as random fluctuations.

Dr. Barr used computer simulation to model what the fossil record might look like over time in the absence of any climate change and found clusters of species originations that were of similar magnitude to the clusters observed in the fossil record. This means random patterns are likely under-credited for their role in speciation fluctuation, he said.

Dr. Barr's findings mean scientists may need to rethink widely-accepted ideas about why human ancestors became smarter and more sophisticated.

"The idea that our genus originated more than 2.5 million years ago as part of a turnover pulse in direct response to climate change has a deep history in paleonthropology," Dr. Barr said. "My study shows that the magnitude of that pulse could be caused by random fluctuations in speciation rates. One implication is that we may need to broaden our search for why our genus arose at that time and place."

He compared the pattern to flipping a coin. If you flip a coin 100 times, you would expect to record 50 heads and 50 tails. However, if you are only looking at 10 coin flips, you could see a greater imbalance, instead recording seven heads and only three tails. This would even out over time, but in the short-run, you could see clusters of these independent coin flips, he said.

Similarly, fluctuations in turnover in Dr. Barr's model are pronounced, but are caused purely by random processes.

"The idea the the origin of Homo is part of a climate-caused turnover pulse doesn't really bear out when you carefully look at the evidence and compare it against other possible explanations," Dr. Barr said.

This research challenges scientists to be careful about the stories they tell about the history of human adaption, Dr. Barr said. Traits that make humans different from our ancestors, like larger brains and greater technological sophistication, could have arisen for a variety of reasons, he said.

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Primordial black holes may have helped to forge heavy elements

Artist’s depiction of a neutron star.

Astronomers like to say we are the byproducts of stars, stellar furnaces that long ago fused hydrogen and helium into the elements needed for life through the process of stellar nucleosynthesis.

As the late Carl Sagan once put it: "The nitrogen in our DNA, the calcium in our teeth, the iron in our blood, the carbon in our apple pies were made in the interiors of collapsing stars. We are made of star stuff."

But what about the heavier elements in the periodic chart, elements such as gold, platinum and uranium?

Astronomers believe most of these "r-process elements" -- elements much heavier than iron -- were created, either in the aftermath of the collapse of massive stars and the associated supernova explosions, or in the merging of binary neutron star systems.

"A different kind of furnace was needed to forge gold, platinum, uranium and most other elements heavier than iron," explained George Fuller, a theoretical astrophysicist and professor of physics who directs UC San Diego's Center for Astrophysics and Space Sciences. "These elements most likely formed in an environment rich with neutrons."

In a paper published August 7 in the journal Physical Review Letters, he and two other theoretical astrophysicists at UCLA -- Alex Kusenko and Volodymyr Takhistov -- offer another means by which stars could have produced these heavy elements: tiny black holes that came into contact with and are captured by neutron stars, and then destroy them.

Neutron stars are the smallest and densest stars known to exist, so dense that a spoonful of their surface has an equivalent mass of three billion tons.

Tiny black holes are more speculative, but many astronomers believe they could be a byproduct of the Big Bang and that they could now make up some fraction of the "dark matter" -- the unseen, nearly non-interacting stuff that observations reveal exists in the universe.

If these tiny black holes follow the distribution of dark matter in space and co-exist with neutron stars, Fuller and his colleagues contend in their paper that some interesting physics would occur.

They calculate that, in rare instances, a neutron star will capture such a black hole and then devoured from the inside out by it. This violent process can lead to the ejection of some of the dense neutron star matter into space.

"Small black holes produced in the Big Bang can invade a neutron star and eat it from the inside," Fuller explained. "In the last milliseconds of the neutron star's demise, the amount of ejected neutron-rich material is sufficient to explain the observed abundances of heavy elements."

"As the neutron stars are devoured," he added, "they spin up and eject cold neutron matter, which decompresses, heats up and make these elements."

This process of creating the periodic table's heaviest elements would also provide explanations for a number of other unresolved puzzles in the universe and within our own Milky Way galaxy.

"Since these events happen rarely, one can understand why only one in ten dwarf galaxies is enriched with heavy elements," said Fuller. "The systematic destruction of neutron stars by primordial black holes is consistent with the paucity of neutron stars in the galactic center and in dwarf galaxies, where the density of black holes should be very high."

In addition, the scientists calculated that ejection of nuclear matter from the tiny black holes devouring neutron stars would produce three other unexplained phenomenon observed by astronomers.

"They are a distinctive display of infrared light (sometimes termed a "kilonova"), a radio emission that may explain the mysterious Fast Radio Bursts from unknown sources deep in the cosmos, and the positrons detected in the galactic center by X-ray observations," said Fuller. "Each of these represent long-standing mysteries. It is indeed surprising that the solutions of these seemingly unrelated phenomena may be connected with the violent end of neutron stars at the hands of tiny black holes."

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Source of Human Heartbeat Revealed in 3-D

Scan of a heart.

A pioneering new study is set to help surgeons repair hearts without damaging precious tissue.

A team of scientists from Liverpool John Moores University (LJMU), The University of Manchester, Aarhus University and Newcastle University, have developed a way of producing 3D data to show the cardiac conduction system -- the special cells that enable our hearts to beat -- in unprecedented detail. The findings were published in Scientific Reports.

The new data in this study gives them a much more accurate framework than previously available for computer models of the heartbeat and should improve our ability to make sense of troublesome heart rhythms like atrial fibrillation that affects 1.4 million people in the UK. The data reveals exactly where the cardiac conduction system is in a normal heart. For example, it shows just how close it runs to the aortic valve.

Professor Jonathan Jarvis who is based at the LJMU School of Sport and Exercise Sciences explained: "The 3D data makes it much easier to understand the complex relationships between the cardiac conduction system and the rest of the heart. We also use the data to make 3D printed models that are really useful in our discussions with heart doctors, other researchers and patients with heart problems.

"New strategies to repair or replace the aortic valve must therefore make sure that they do not damage or compress this precious tissue. In future work we will be able to see where the cardiac conduction system runs in hearts that have not formed properly. This will help the surgeons who repair such hearts to design operations that have the least risk of damaging the cardiac conduction system."

Co-author Dr Halina Dobrzynski, who is based in The University of Manchester's Cardiovascular Division, has been working on the anatomy of the cardiac conduction system for 20 years. She says: "This is just the beginning. The British Heart Foundation is supporting my group to visualise this system in 3D from aged and failing hearts. With my research assistant Andrew Atkinson and working with Professor Jonathan Jarvis, Robert Stephenson and others, we will produce families of data from aged and failing hearts in 3D."

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Unknown virus discovered in 'throwaway' DNA

A chance discovery has opened up a new method of finding unknown viruses.

A chance discovery has opened up a new method of finding unknown viruses.

In research published in the journal Virus Evolution, scientists from Oxford University's Department of Zoology have revealed that Next-Generation Sequencing and its associated online DNA databases could be used in the field of viral discovery. They have developed algorithms that detect DNA from viruses that happen to be in fish blood or tissue samples, and could be used to identify viruses in a range of different species.

Next-Generation Sequencing has revolutionised genomics research and is currently used to study and understand genetic material. It allows scientists to gather vast amounts of data, from a single piece of DNA, which is then collated into huge, online, genome databases that are publicly accessible.

Dr Aris Katzourakis and Dr Amr Aswad, Research Associates at Oxford's Department of Zoology, initially discovered the new use for the database, by chance. While looking for an ancient herpes virus in primates, they found evidence of two new undocumented viruses.

Spurred by their accidental discovery, they set out to see if they could intentionally achieve the same result. In a separate project to find new fish-infecting herpes viruses, they used the technique to examine more than 50 fish genomes for recognisable viral DNA. Sure enough, in addition to the herpes viruses they were expecting to find, the researchers identified a distant lineage of unusual viruses -- that may even be a new viral family. The traits were found scattered in fragments of 15 different species of fish, including the Atlantic salmon and rainbow trout.

To confirm that the viral evidence was not simply a fluke, or a data processing error, they tested additional samples from a local supermarket and sushi restaurant. The same viral fragments were found in the bought samples.

Study author Dr Aris Katzourakis, from Oxford University's Department of Zoology, said: 'In the salmon genome we found what seems to be a complete and independent viral genome, as well as dozens of fragments of viral DNA that had integrated into the fish DNA. We know from recent studies that viruses are able to integrate into the genome of their host, sometimes remaining there for millions of years. In this case, it looks like the virus may have acquired the ability to integrate by stealing a gene from the salmon itself, which explains how it has become so widespread in the salmon genome.'

The key to the success of this research is in its inter-disciplinary approach, combining techniques from two fields: evolutionary biology and genomics. Together, these are at the core of the new field of paleovirology -- the study of ancient viruses that have integrated their DNA into that of their hosts, sometimes millions of years ago. Each technique used has been developed to analyse huge quantities of DNA sequence data.

Co-author and Research Associate at Oxford's Department of Zoology and St. Hilda's College, Dr Amr Aswad, said: 'Discovering new viruses has historically been biased towards people and animals that exhibit symptoms of disease. But, our research shows how useful next generation DNA sequencing can be in viral identification. To many, viral DNA in say, chimp or falcon data is a nuisance, and a rogue contaminant that needs to be filtered from results. But we consider these an opportunity waiting to be exploited, as they could include novel viruses that are worth studying -- as we have found in our research. We could be throwing away very valuable data.'

Finding new viruses has historically not been an easy process. Cells do not grow on their own, so must be cultured in a laboratory before they can be analysed, which involves months of work. But the Oxford research represents a massive opportunity for the future.

Beyond this study, the approach could be used to identify viruses in a range of different species, particularly those known to harbour transmissible disease. Bats and rodents, for example, are notorious carriers of infectious disease that they are seemingly immune to. Insects such as mosquitoes are also carriers of viral diseases that harm humans, such as Zika. If applied effectively the method could uncover other viruses before an outbreak even happens.

Dr Katzourakis added: 'One of the real strengths of this technique, as compared to more traditional virology approaches, is the speed of discovery, and the lack of reliance on identifying a diseased individual. The viral data collected, that may otherwise be discarded as a nuisance, is a unique resource for looking for both pathogenic and benign viruses that would otherwise have remained undiscovered.'

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On the early human's menu: Mammoth and plenty of raw vegetables

Occipital bone of an anatomically modern human from the fossil site Buran-Kaya III.

Senckenberg scientists have studied the diet of anatomically modern humans. With their recent study, published in the journal Scientific Reports, they were able to refute the theory that the diet of early representatives of Homo sapiens was more flexible than that of Neanderthals. Just like the Neanderthals, our ancestors had mainly mammoth and plants on their plates -- the researchers were unable to document fish as part of their diet. Therefore, the international team assumes that the displacement of the Neanderthals was the result of direct competition.

The first representatives of Homo sapiens colonized Europe around 43,000 years ago, replacing the Neanderthals there approximately 3,000 years later. "Many studies examine the question of what led to this displacement -- one hypothesis postulates that the diet of the anatomically modern humans was more diverse and flexible and often included fish," explains Prof. Dr. Hervé Bocherens of the Senckenberg Center for Human Evolution and Palaeoenvironment (HEP) at the University of Tübingen

Together with his colleague, Dr. Dorothée Drucker, the biogeologist from Tübingen now set out to get to the bottom of this hypothesis. In conjunction with an international team, he studied the dietary habits of early modern man on the basis of the oldest know fossils from the Buran Kaya caves on the Crimean Peninsula in the Ukraine. "In the course of this study, we examined the finds of early humans in the context of the local fauna," explains Drucker, and she continues, "Until now, all analyses of the diet of early modern humans were based on isolated discoveries; therefore, they are very difficult to interpret."

In order to reconstruct our ancestor's menu -- despite the lack of a fossil dietary record -- the team around the scientists from Tübingen measured the percentage of stable carbon and nitrogen isotopes in the bones of the early humans and the locally present potential prey animals such as Saiga, horses, and deer. In addition, they also analyzed the nitrogen-15 content of individual amino acids, making it possible to not only determine the origin, but also the proportion of the nitrogen. "Our results reveal a very high proportion of the nitrogen isotope 15N in early modern humans," adds Bocherens, and he continues, "However, contrary to our previous assumptions, these do not originate from the consumption of fish products, but primarily from mammoths."

And yet another result came as a surprise for the scientists: The proportion of plants in the diet of the anatomically modern humans was significantly higher than in comparable Neanderthal finds -- mammoths, on the other hand, appear to have been one of the primary sources of meat in both species.

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Egyptologists Embrace Cutting-Edge Technology to Solve Ancient Mysteries

The Pyramids of Menkaure, Khafre and Khufu, Giza Necropolis (UNESCO World Heritage List, 1979), Egypt. Egyptian civilization, Old Kingdom, Dynasty IV.

From the Giza pyramids to the pharaonic tombs of Luxor, Egypt's ancient monuments are holding onto mysteries which researchers now aim to unravel with cutting edge technology.

For more than 200 years since Napoleon Bonaparte landed in Egypt with a retinue of scholars who laid the groundwork for modern Egyptology, experts have used science to unlock the secrets of the country's ancient treasures.

In the 21st century, the scientists have been using electronic devices and chemical testing to date artifacts.

Chemical testing still requires small samples, but advanced techniques coming into use are meant to be noninvasive so as not to damage the ancient relics.

ScanPyramids is among the most ambitious of the projects to demystify the Khufu Pyramid near Cairo, the only surviving monument from the ancient Seven Wonders of the World.

It has employed infrared thermography and muography — a technique that records images using muon particles — in its quest.

The project had announced last October that the massive pyramid may contain undiscovered recesses.

"All the devices we put in place are designed to find where the cavity is located. We know there is one, but we're trying to find out where," said Mehdi Tayoubi, president of the HIP Institute heading the ScanPyramids project.

The muon devices include chemical emulsion instruments from Japan's University of Nagoya, electronic sensors from the KEK Japanese Research Laboratory, and muon telescopes from the French Atomic Energy Commission.

The results are then compared with infrared and 3D images.

Some archaeologists have pinned hopes on the sophisticated technology to locate the burial place of the legendary queen Nefertiti.   

The wife of King Akhenaten, who initiated a monotheistic cult in ancient Egypt, Nefertiti remains an enigma, best known for a bust depicting her that is now on exhibition in Berlin's Neues Museum.

A British Egyptologist, Nicholas Reeves, believed her remains were hidden in a secret chamber in the tomb of Tutankhamun, in the southern Valley of the Kings.

In 2015, archaeologists scanned the tomb with radar hoping for clues.

Both Reeves's theory and the inconclusive results have been dismissed by other Egyptologists.

One of them, former antiquities minister Zahi Hawass, said that an adept of the sun god Aton would never have been allowed to be buried in the Valley of the Kings.

Mapping out ancient dynasties

The excitement over the possible discovery has died down since the inconclusive results, but a team from Politecnico University in Turin, Italy, intends to give it another shot.

This time they will employ tomography — a method used in medical scans — and magnetometry, which measures magnetic fields.

Neither the Politecnico team nor the antiquities ministry has been inclined to discuss the fresh attempt, possibly put off by the anticlimactic media frenzy over the previous bid.

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Primordial asteroids discovered

Astronomers have identified the oldest asteroid families and, by process of elimination, the oldest intact asteroids in the main belt. A team including SwRI scientists developed a technique to identify ancient asteroid families that have drifted apart. Asteroid surfaces heat up during the day (as illustrated by this image) and cool down at night, giving off radiation that can act as a sort of mini-thruster. This force can cause asteroids to drift widely over time, making it difficult to identify families of fragments leftover after asteroid collisions eons ago.

Southwest Research Institute (SwRI) was part of an international team that recently discovered a relatively unpopulated region of the main asteroid belt, where the few asteroids present are likely pristine relics from early in solar system history. The team used a new search technique that also identified the oldest known asteroid family, which extends throughout the inner region of the main asteroid belt.

The main belt contains vast numbers of irregularly shaped asteroids, also known as planetesimals, orbiting the Sun between Mars and Jupiter. As improved telescope technology finds smaller and more distant asteroids, astronomers have identified clusters of similar-looking bodies clumped in analogous orbits. These familial objects are likely fragments of catastrophic collisions between larger asteroids eons ago. Finding and studying asteroid families allows scientists to better understand the history of main belt asteroids.

"By identifying all the families in the main belt, we can figure out which asteroids have been formed by collisions and which might be some of the original members of the asteroid belt," said SwRI Astronomer Dr. Kevin Walsh, a coauthor of the online Science paper detailing the findings. "We identified all known families and their members and discovered a gigantic void in the main belt, populated by only a handful of asteroids. These relics must be part of the original asteroid belt. That is the real prize, to know what the main belt looked like just after it formed."

Identifying the very oldest asteroid families, those billions of years old, is challenging, because over time, a family spreads out. As asteroids rotate in orbit around the Sun, their surfaces heat up during the day and cool down at night. This creates radiation that can act as a sort of mini-thruster, causing asteroids to drift widely over time. After billions of years, family members would be almost impossible to identify, until now. The team used a novel technique, searching asteroid data from the inner region of the belt for old, dispersed families. They looked for the "edges" of families, those fragments that have drifted the furthest.

"Each family member drifts away from the center of the family in a way that depends on its size, with small guys drifting faster and further than the larger guys," said team leader Marco Delbo, an astronomer from the Observatory of Cote d'Azur in Nice, France. "If you look for correlations of size and distance, you can see the shapes of old families."

"The family we identified has no name, because it is not clear which asteroid is the parent," Walsh said. "This family is so old that it appears to have formed over 4 billion years ago, before the gas giants in the outer solar system moved into their current orbits. The giant planet migration shook up the asteroid belt, removing many bodies, possibly including the parent of this family."

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We Could Be on the Threshold of a New Era of Color Science

Sunset over the colorful tulip fields in Karatay, Konya, Turkey on April 13, 2016.

An international team of 27 scientists has just declared that we are on the threshold of a new era of color science that could have far-reaching impacts on everything from the security industry to our understanding of animal and human behavior.

The declaration, published in the journal Science, follows multiple advances in the study of animal and plant coloration.

“New technology is opening new windows into exploration of color perception, production, and function,” senior author Tim Caro of the University of California, Davis, said.

Co-author Justin Marshall of the University of Queensland recently determined that mantis shrimp have four times as many color receptors as humans do. He explained that we have three — red, green, and blue — while the shrimp have twelve.

Lead author Innes Cuthill of the University of Bristol said mantis shrimp use those extra color channels to analyze light coming from objects in ways much different than humans and most other animals.

“They analyze light like a machine called a spectrometer, which a physicist would use to measure how much light there is in a set of wavebands,” he said. “We, and most other animals, instead transform the relative amounts of light in different wavebands into a single continuous percept: the sensation we call color.”

Peacock mantis shrimp (Odontodactylus scyllarus) photographed in the Andaman Sea, Thailand

Animals see the world differently than we do. For example, no human has yet set eyes on “bird white.” What we think of as “white” could also be something completely different to a bird.

“Objects that all look white to us may look different to a bird depending on how much ultraviolet light there is,” Cuthill said. “If there’s as much UV as blue, green, and red, that would be ‘bird white.’ If there was no UV, then that would be a saturated primary color to a bird, one we cannot imagine.”

Another recent finding in the field of color biology suggests patterns of color on a species can signal how well an individual can fight. Co-author Elizabeth Tibbetts of the University of Michigan first noted that black facial patterns vary on paper wasps. She then discovered that females with larger or a greater number of irregular black marks on their faces tended to win fights with their rivals.

Tibbetts explained that the facial signals help reduce the costs of conflict.

“Lots of animals have color patterns that convey information about fighting ability: birds, lizards, fish, mammals, insects,” she said. “It’s the animal version of advertising your fighting prowess with karate belt color. If you are a wimpy wasp, it doesn’t make sense to challenge the strongest wasp in the neighborhood to a fight.”

European paper wasp

Body coloration can be tied to many behaviors. Humans are not exempt from the color-behavior connection. In fact, many people who head to a sunny climate for spring or summer vacation may exemplify the phenomenon.

Caro explained that skin color in humans is the result of a trade-off between avoiding the harmful effects of ultraviolet radiation and the beneficial effects of vitamin-D production caused by sunlight hitting the skin.

“This trade-off can affect behavior,” he continued. “For example, people in northern European climates like to take advantage of the sun in spring and sunbathe to produce vitamin D after the long winter.”

Color in nature is usually tied to honest visual information. Human heritage, in this way, is reflected in an individual’s skin color.

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Exceptionally Well-Preserved Dinosaur Had Hefty Armor and Elaborate Camouflage

Right side of Borealopelta markmitchelli’s head

On March 21, 2011, mining machine operator Shawn Funk at the Suncor Millennium Mine in Alberta, Canada, spotted some unusual rock formations that he suspected could contain fossils. Since a bunch of plesiosaur and ichthyosaur remains had been previously excavated from the region, Donald Henderson, who is the curator of dinosaurs at Royal Tyrrell Museum in Drumheller, Canada, and a crew were sent to the mine to investigate.

Henderson and his colleagues at first were baffled by the fossils, which looked nothing like the marine reptile remains that had been unearthed in the Alberta area. The chunk of rock encasing the fossils was transported to the museum, where technician Mark Mitchell spent more than 7,000 hours slowly and gently removing material away from the specimen. When paleontologist Caleb Marshall Brown of the museum first saw the preserved beast in full, his jaw dropped.

There, in vivid 3D, was a nodosaur, which is a type of hefty armored dinosaur.

“This specimen is one of the best-preserved dinosaur specimens ever found,” Brown said. “What sets this nodosaur apart from other exceptionally preserved dinosaur specimens, is the unique combination of both abundant skin preservation and retention of the original three-dimensional form of the body.”

“This unique combination means that, with the exception of the color, the animal looks the same today as it did when it was alive,” he added. “It is almost as if the animal went to sleep and turned to stone — a fossil masterpiece.”

In honor of Mitchell, the dinosaur was named Borealopelta markmitchelli. The new species, now considered to be the world’s best-preserved armored dinosaur, is described in the journal Current Biology. Dated to 110 million years ago, this “dinosaur equivalent of a tank,” according to the authors, weighed in at more than 2,800 pounds and grew to at least 18 feet long.

The mine site during the Early Cretaceous was a sea, which is one reason why Henderson and his team first thought the fossils belonged to a marine reptile. The researchers, whose work was supported by the National Geographic Society, can piece together the extraordinary circumstances that led to the dinosaur’s preservation.

Henderson explained that, after the dino died, its armor still would have been anchored into the skin in a dense, collagenous mesh.

“This armor would have deterred scavengers from trying to pull off chunks while it floated on the water surface,” he said. “The thick hide also was able to contain the high gas pressure that would have built up inside the decaying carcass. A fully inflated, super buoyant carcass was able to float far offshore away from damaging waves crashing on a beach.”

An illustration of the 110-million-year-old Borealopelta markmitchelli discovered in Alberta, Canada

The dinosaur’s body wall did eventually rupture. The carcass then drifted down to the seabed in water that was at least 164 feet deep. Few fossils from burrowing species exist at that spot, suggesting low-oxygen conditions with little biological activity. There, the carcass remained undisturbed until Funk’s fateful day.

The animal’s thick hide, which aided preservation of the remains, still retains organic material, such as pigments. These biomolecules show that B. markmitchelli had reddish-brown skin that was darker at the top and lighter on the animal’s underside. This light-dark combination is common in animals alive today and is known as countershading.

Co-author Jakob Vinther of the University of Bristol explained that countershading helps animals to blend into their landscapes, camouflaging their 3D forms. The dinosaur lived in a dry and open environment where the ground and vegetation exhibited earthen tones of brown, yellow, and red. Its reddish-brown hues strengthened the camouflage effect.

It was thought that few predators dared to take on husky armored dinosaurs, but B. markmitchelli evolved more for defense than offense. Brown and Henderson suspect that Acrocanthosaurus, a gigantic meat-loving dinosaur that measured around 38 feet long and weighed about 6.8 tons, hunted the armored dinosaur.

“The best anti-predatory defense that Borealopelta had would have been avoiding detection in the first place, and then looking like an unappetizing meal — by being covered in bony armor,” Brown said.

Frontal view of Borealopelta markmitchelli

Henderson agreed, adding that the nodosaur probably hunkered down as a last resort, hoping that its armor would hold if the predator tried to take a bite.

The dinosaur is so well preserved that organic remains of its last meal appear to be present in its fossilized gut. Vinther said he and his colleagues “have some idea” concerning what this meal consisted of, but they wish to conduct a chemical analysis and other investigations before coming to a conclusion.

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