On April 25th, 2018 we learned about

Mini model meteorites demonstrate how well hot rocks can deliver water to dry planets

While we live on an impressively wet planet today, the Earth probably didn’t start out with our lush collections of rivers, lakes and oceans. With no obvious way for the planet’s iron and other minerals to have spontaneously transmuted into H2O billions of years ago, scientists have long suspected that our water was instead delivered from space via icy objects like comets. Further research found that our water looked more like the water found on icy asteroids like Ceres, which was clearly abundant in the asteroid belt, but it still posed a problem. Asteroids tend to burn and explode a lot when they get too close to the Earth, so how would any of their water survived long enough to help soak our planet?

Proxy-asteroid projectiles

With no asteroids or spare planets at their disposal, researchers from Brown University turned to the Vertical Gun Range at the NASA Ames Research Center to simulate icy impactors. Marble-sized projectiles were fabricated to match the composition of carbonaceous chondrites, or meteorites suspected of being formed in ancient, icy asteroids. The miniature proxy-meteors were then fired at a chunk of dry pumice powder, which served as their stand-in for the once-parched surface of the Earth.

The small impactors hit their targets at more than 11,000 miles-per-hour, releasing heat and an impressive amount of debris in all directions. As with real asteroid impacts, enough heat was generated in these collisions to outright destroy some material, including some of the water ice. However, some of the mineral content also melted, which weirdly enough was key to some of the water’s survival. Because the rock melted and re-cooled so quickly, it could capture some of the water inside the resulting glass, keeping it “safe” from vaporizing. Additional water was similarly captured by flying breccias— random debris thrown and heated by the impact that were hot enough to become “welded” together.

Making sense of previous predictions

This experiment not only helps explain some of the water on Earth, but also some of the confusing H2O around the solar system. Since previous estimates found that asteroid impacts should vaporize water, researchers had a hard time explaining the presence of water in impact craters on places like the Moon and Mercury. The physical test proved that those estimates hadn’t captured the full complexity of such an impact, and that delivering water via screamingly-fast hunks of icy rock is apparently more practical than you might think.


My five-year-old asked: What does the Vertical Gun Range look like?

“Gun” may be a misleading term here, because the equipment in question doesn’t really look much like pistol, rifle or cannon, at least outside science fiction. A large barrel launches a projectile into an enclosed, reinforced chamber. That chamber is outfitted with a number of sensors and cameras so that researchers can learn more details about the behavior of whatever collision is being studied. NASA has more on the AVGR in this handy PDF.

Source: Projectile cannon experiments show how asteroids can deliver water by Brown University, Phys.org

On April 23rd, 2018 we learned about

Crocodiles can change their skin coloration based on environmental color cues

Few predators would antagonize an adult saltwater crocodile (Crocodylus porosus). Weighing close to a thousand pounds, these huge reptiles have little to fear in their local ecosystems. Their hatchlings, on the other hand, are usually around 2.5 ounces at birth, and need to be a bit more wary about becoming someone’s lunch. To stay safe, these tiny crocs, as well as other members of the Crocodylidae family, have developed the ability to better hide themselves by changing the color of their skin. Through a series of experiments, researchers have been able to isolate the exact mechanisms that allow these scaly predators to obscure themselves according to environmental conditions.

Shading skin according to what they see

The color changes in question are noticeable to the naked eye, assuming you’re comfortable staying in proximity to a crocodile for 60 to 90 minutes. While no crocodile was observed creating new patterning or bright shifts in hue like a chameleon, they could shift their skin from lighter to darker shades of their normal coloration. Members of the Crocodylus genus, like saltwater crocodiles, would make their tails, backs, and heads turn darker in darker environments, while members of the Gavialidae family did the opposite, lightening their backs when placed in dark environments.

In the context of this study, dark environments consisted of black or white tubs of water. It was easy to see the crocodiles change color according to their surroundings, but researchers needed to make sure that this was really triggered by what each animal was seeing, rather than other conditions like body temperature or stress levels. One way to do this was to place a crocodile in one color tub, blindfold it, then move it to the opposite lighting conditions. In those cases, the crocodiles’ coloring didn’t change according to the new environment- they kept the color that matched the last environment that their eyes were able to see. This was fairly conclusive, particularly after factors like temperature and stress hormones were found to be consistent between light and dark tubs. Finally, tests with red lights, which crocodiles don’t see as well as colors like blue, showed that if the crocodile didn’t visually perceive the difference, their skin didn’t react either.

Pinching and stretching pigments

Of course, visual stimulation can only be part of the story. Researchers also examined the crocodiles’ skin to see how it could change color once the animal noticed it was in a dark or light environment. They found that an α-melanocyte-stimulating hormone was released in the body, which triggered changes in cells’ melanosomes. When a crocodile needed to darken, the pigment in the melanosome would spread out, increasing the percentage of each cell that would absorb light. When a crocodile lightened, the same melanosomes would contract into tight packets, leaving more surface area without pigment to absorb light. This expansion and contraction is all that’s needed to achieve the relatively quick but reversible color change seen across multiple species’ skin.

Estimating when this abilities evolved

The species of crocodile that change colors revealed some information about when this ability likely evolved. Alligators, for instance, don’t change colors, which suggests that this ability had not developed when that family split from Crocodylidae 80 million years ago. Outside the genus Crocodylus, two African members of Crocodylidae showed little to no color-shifting ability, which then suggests that this trait evolved after that branch in the family tree occurred 30-40 million years ago. However, Crocodylus diversified a lot around 12 to 17 million years ago, so researchers assume that this trait was likely established by then in order for it to turn up in species that have since become separated from each other.


My third-grader asked: Do adult crocodiles do this too, or is it just the babies? Why do some of them turn the opposite color? Are they sure the pigment isn’t to help prevent sunburns?

The tests were done with baby crocodiles, possibly because they’re a lot easier to move between tubs of water. However, adults would benefit from dynamic coloration, as hiding from prey would aid in the ambush-style hunting crocodiles typically rely on.

The benefits of Gavialidae crocodiles’ reversed coloration wasn’t directly tested in this study. Researchers speculate that it acts like a form of countershading, similar to the way a shark’s white belly makes it harder to see when viewed as a silhouette from below. If true, this further supports the notion that adult crocodiles make use of these abilities to help them surprise their prey.

The sunburn question was likely sparked by Claude, the albino alligator living at San Francisco’s California Academy of Sciences. As an albino, Claude had no pigment it his skin, putting him at greater risk from ultraviolet light damage (and predation! and being spotted by prey!) While it might seem handy to be able to activate built-in sunscreen on command, it’s hard to see how that would benefit an animal more than good protection all the time. Since these animals mostly live in equatorial regions, they wouldn’t really have a pressure to decrease their ultraviolet light protection at any point, making the perception to hormone to melanosomes system needless complicated. Temperature control would seem like a better tool for a cold-blooded reptile to have, but the study directly controlled for temperature changes, and found that it didn’t influence the crocodile’s coloration.

Source: Crocodiles Alter Skin Color in Response to Environmental Color Conditions by Mark Merchant, Amber Hale, Jen Brueggen, Curt Harbsmeier & Colette Adams, Scientific Reports, volume 8

On April 23rd, 2018 we learned about

Testing if know-it-alls actually know more than the average person

Nothing elicits eye-rolling like a statement starting with “you know what your problem is…” Once someone crosses the line from confident to overconfident, it’s hard to feel anything but annoyed at what a speaker has to say. Rather dutifully, scientists posed an uncomfortable question though— what if know-it-alls, or those with “belief superiority,” truly deserved the praise they’d heap upon their own opinions? It wasn’t that scientists were looking to pat these folks on the back— they were characterized as people who already felt they knew more than other people, after all. The hope was that if know-it-alls actually did know more than their peers, then maybe we could all learn some of the techniques they employed to gain that knowledge, possibly making learning easier for everyone.

Know-it-alls don’t know better

For better or for worse, it turned out that society’s low opinion of belief-superior people was right all along. When quizzed on topics they claimed to have a special mastery of, know-it-alls didn’t actually know as much as they’d claim, demonstrating no special grasp of information at all. Conversely, people who spoke more humbly of their knowledge often performed better than they predicted.

The over-inflated opinions of belief-superior people seems related to the Dunning-Kruger effect, wherein people who don’t know how limited their knowledge is greatly overestimate their mastery of a topic. However, a second phase of this experiment found an important wrinkle in that model. Even though belief-superior people didn’t show any advantage in their knowledge, researchers still tested how they seek out new information. When offered six sources of information on a topic, know-it-alls tended to purposely pick sources that they thought would agree with their own opinions. This indicates that they knew other ideas existed, but seemed to prefer hearing their own “expertise” echoed back to them.

More than mere opinions

Some of this may not be the know-it-all’s fault. Other studies have previously looked at how even average people react to opinions contrary to their own on neurological level. By monitoring brain activity in an fMRI, researchers found that ideas that conflicted with test participant’s opinions were processed by the brain like physical threats. This may help explain why simply being exposed to contrasting opinions doesn’t change minds very easily; in at least one experiment, contrary opinions actually reinforced readers’ original viewpoints, pushing them towards political extremes. Belief-superiority doesn’t require an extreme viewpoint, of course, but all these factors may help explain why overconfident beliefs can feel so insufferable.

Source: Scientists Tested How Much Know-It-Alls Actually Know, And The Results Speak For Themselves by Futurity, Science Alert

On April 19th, 2018 we learned about

Fossilized, cavity-ridden teeth reveal bears’ long history of eating high-sugar foods to prepare for hibernation

Skeletal fossils help describe the shape of an ancient creature, as they were literally part of the animal’s anatomy. Trace fossils record an interaction of some sort, such when a dinosaur stepped into some soft mud to make a footprint. In some cases, paleontologists get lucky, and find both types of evidence at once, as with a collection of cavity-pocked bear teeth found On Ellesmere Island in Canada.

The 3.5 million-year-old teeth not only describe the dental anatomy of two Protarctos abstrusus, but they show evidence of how their behavior ate holes in their teeth. Eliminating speculation about what events lead to the small bears’ dental decay, the fossils were found alongside an ancient collection of raspberry, blueberry, lingonberry and crowberry plants. Like 44 percent of modern bears, it seems that a love of sugar-filled foods caused a fair amount of damage to these animals’ teeth while they were alive.

Bulking up for winter since bears began

The evidence suggests that this kind of sugary, high-calorie diet was readily available millions of years ago, but it certainly isn’t present any longer. The area is now a polar desert, but in the Pliocene it was 20 degrees warmer, and able to support a forest full of trees, primitive horses, beavers and deer. However, the winters were cold enough to freeze, which is probably why P. abstrusus was looking to bulk up on berries— all that sugar would have helped the bear pack on fat to help it hibernate when food was scarce.

If those berry-binges truly were part of the bears’ preparations for winter, it would be the earliest known example of this behavior. While this species is not thought to have been a direct ancestor of modern species like the black bear, the fact that it hibernated to survive northern winters shows that this strategy must have developed very early on in bears’ evolution.

Source: Primitive fossil bear with a sweet tooth identified from Canada’s High Arctic, Canadian Museum of Nature

On April 19th, 2018 we learned about

A meteorite delivered diamonds carrying traces of our solar system’s less successful protoplanets

Building a planet out of dust isn’t easy. Sure, the recipe basically requires innate forces like gravity to do a lot of the work, but not every clump of debris successfully forms into a durable planet. Those first steps are called protoplanets, and while we’ve seen them around other stars, we’ve only recently found evidence of the protoplanets that helped build the planets in our own solar system.

Learning from dirty diamonds

The evidence found in diamonds carried to Earth in a meteorite that struck the Earth in 2008. Those diamonds carried small bits of other metals and minerals that were present when the diamond was formed. The composition and structure of this extra material, known as inclusions, can tell us a lot about the conditions that created the diamond.

In this case, the structure of the diamond indicates that it was formed as an achondrite— a rock formed in an object large and hot enough to create a metallic core inside a layer of rock. That could include very large asteroids, but other features of these diamonds make it more likely to have been formed in a larger protoplanet instead. The inclusions also show that these diamonds were formed under at least 20 gigapascals of pressure, well beyond diamond’s normal elastic breaking point. With that reference point, geophysicists can estimate that the protoplanet that created these diamonds was somewhere between the size of Mercury and Mars.

This may seem like a crazy amount of information to infer from a single space rock, but we’ve been reading history from diamonds here on Earth for years. Actually, we’ve been getting history out of the Earth, as diamonds are known to carry information about the formation and movement of materials deep under the Earth’s crust, carrying them to the surface like shiny time-capsules, including deposits of water over a 100 miles below the Earth’s surface.

Potential planets from the past

None of this suggests that we have a new planet forming next door. Simulations of our solar system’s formation predicted that multiple protoplanets formed within 10 million years of our Sun’s formation. While at least eight of those objects managed to survive long enough to become the planets we know today, the diamonds found in the 2008 meteorite are probably just pieces of some of the other protoplanets that were destroyed in collisions in a more crowded solar system.

 

Source: Diamonds in Meteorite May Hail from Our Ancient Solar System by Doris Elin Slazar, Space.com

On April 17th, 2018 we learned about

Mosquitoes let researchers indirectly monitor the movements of invasive pythons

Burmese pythons (Python bivittatus) often grow up to twelve-feet long, but they’re still surprisingly hard to find in the wild. This is bad enough for the prey these snakes want to ambush, but it’s created challenges for researchers tracking their activity as well, even in environments where these snakes aren’t supposed to live. Since the 1980s, failed pet-owners have been importing and releasing pythons in the Florida Everglades, harming the native wildlife in those swamps. Fortunately, one local species seems to be quite adept at locating pythons, which is why researchers are “recruiting” mosquitoes to help track the snakes.

Following snakes via swarming mosquitoes

Despite the mobility of an individual mosquito, they’re still easier to capture than a single Burmese python. The work starts with cardboard funnels and hand-held vacuum cleaners, but is then followed with DNA sequencing in the lab to see what species of animals the mosquitoes have been eating. When python DNA turns up, it lets researchers construct a map of where they’re moving, and possibly how they’re multiplying across the Florida swamps.

Since this work started in 2015, a few trends are already clear. Python populations have been growing, and expanding northward. At this point researchers don’t have a strict head-count on the snakes, but they know that there are enough to be making an impact on other species in the Everglades. Raccoons, for instance, have been getting eaten often enough that the turtle and alligator eggs they usually eat are hatching at unusually high rates.

Other types of tracking

If digging through mosquito stomachs seems too indirect, conservationists have a few other ways to follow invasive pythons. One option is to collect samples of dirt found near burrows, then dig through them for traces of python DNA. Each time a snake slithers by, it sheds a bit of DNA, eventually leaving enough to confirm activity in specific locations.

For something a bit more actionable, there’s the sentry snake program, conducted by the Conservancy of Southwest Florida. Male pythons are outfitted with radio trackers, then released back into the wild where they’ll hopefully find a mate, and possibly some friends. Once contact seems to be made, conservationists can raid the “aggregation” of snakes, capturing other males and any fertile female snakes that were fertilizing eggs. This method is rather labor intensive, but it has led to the removal of over 3,000 fertilized eggs from the Florida swamps before they had a chance to hatch.

Source: A UF researcher is tracking snakes using mosquitoes by Wyatt Schreiber, The Alligator

On April 17th, 2018 we learned about

Describing, and disabling, a carnivorous plant’s version of consciousness

“Wait, how do plants know things? Do they know things? They can’t, right?”

My third-grader’s brow furrowed as she ran scenarios over in her head. Plants aren’t the same as animals. They don’t have muscles to move with. They don’t have eyes like we do, and no brain to do any thinking. Nonetheless, they are known to follow the Sun, open and close flowers, and even react to the sound of predators eating their neighbors’ leaves. How was any of this possible without the anatomical gear we depend on to do any of those jobs?

It’s a tough question, and we don’t know all those answers yet. The sound sensory in particular is quite odd, but fortunately, some very reactive plants have helped botanists figure out how a plant can sense and respond to stimuli without nerve cells and a brain to do so. Because carnivorous plants like the Venus flytrap (Dionaea muscipula) and sundew plants (Drosera) have to actively trap their prey, they need to operate in a time-frame that matches the critters they want to catch. To do that, the plants are relying on so-called trigger hairs that essentially give the plant a way to “sense” when something has touched it.

As the titular fly lands on the attractively-scented “lobe” at the end of a leaf, it’s likely to bump into one or more trigger hairs. Unlike your nerve cells, those hairs don’t report back to any brain to trigger further activity. Instead, they create an action potential, which is an electrical charge that builds up in the trigger cell, eventually reaching a threshold where it gets discharged to the next cell, and the next, and the next. Eventually, this signal reaches the plant’s version of a muscle cell, which either expands or contracts to change the water pressure along the joint of the mouth-shaped lobe, causing it to close shut on the bug. With further stimulation of those trigger hairs, the flytrap will start to excrete digestive enzymes to it can actually eat its prey.

Turning off the trigger hairs

Even though trigger hairs aren’t exact matches for animal nerve cells, they’re close enough that they can be used to study the effects of the general anesthetics we use on animals. Even though those drugs are used every day to numb and temporarily paralyze people in surgery, we don’t know exactly how they do it. By using them on reactive plants like Venus flytraps and the “shy plant” Mimosa pudica, researchers are getting closer to understanding the exact cellular mechanisms that make modern surgery possible.

The answer seems to go back to the idea of action potentials, and how they get started in the first place. In both the plants trigger cells and animal nerves, a charge is built up on the outside of the cell membrane or wall. In the membrane are openings called ion channels that open and close when specific molecules are present to unlock them, a bit like a key opening a gate. Charged molecules, ions, can then move into the cell, helping it accumulate a larger charge, until eventually it triggers the release of an electrical charge to kick off another cell.

Paralyzing the plants

When carnivorous plants were subjected to anesthetics like diethyl ether, their trigger cells became unresponsive. The shy plant didn’t curl its leaves. Flytraps didn’t close after being poked. More importantly, no charge was detected at the plants’ trigger cells, indicating that the ion channels weren’t opening, heading off any action potential before it started. A second test with the roots of a mustard plant, Arabidopsis thaliana, found that the lipids, or fat proteins, in the cell membrane were being disrupted, helping researchers narrow their focus even further.

This wasn’t done to numb Venus flytraps, of course. They seem to be quite good at regulating their own activity already; they only close if multiple hairs have been touched, don’t usually close down on their pollinators, and reserve digestive enzymes for when they really have lunch in their clutches. Instead, this work may help us understand and then design better anesthetics for humans and other animals, taking some of the trial and error out of how we temporarily stop each other from sensing the world around us.

Source: We can make plants pass out—with the same drugs that mysteriously knock us out by Beth Mole, Ars Technica

On April 15th, 2018 we learned about

Beyond bugs, mammals, birds and reptiles play big roles in the pollination of flowering plants

On paper, the tongue of a Pallas’ long-tongued bat (Glossophaga soricina) may sound a bit like something from a horror movie. The South American bat’s tongue is made of spongy, erectile tissue, allowing it to increase its length by 50 percent when engorged with blood. It’s covered in an array of tiny, densely-packed hairs, which then stand perpendicular to the tongue when fully extended, allowing it to better capture the fluids the bat devours to stay alive. In practice though, none of this seems very grotesque, because G. soricina only uses its tongue to lap up nectar out of flowers, placing this bat in a niche closer to a honeybee than a vampiric parasite.

Scientists studying pollinators have found that the importance of vertebrate pollinators like G. soricina may be widely underappreciated. For all the attention played to pollinating bees and butterflies, a large number of plant species largely depend on bigger critters like bats, mice and even lemurs to fertilize their flowers. These aren’t strictly fringe cases either, as some flowers have evolved to be highly specialized, and thus dependent on just the right species of mammal or bird to be able to reproduce.

Nectar-eating bats and birds

Among mammals, bats are the most common pollinators, sometimes accounting for 83 percent of fruit production in a geographic region. They’re known to pollinate close to 530 species of plants around the world, often in relatively exclusive arrangements. For example, the blue agave cactus (Agave tequilana) which is used to make tequila, only open their flowers at night in order to attract greater (Leptonycteris nivalis) and lesser (Leptonycteris yerbabuenae) long-nosed bats. These bats don’t have hairy tongues, but the hair on their bodies collect and spread pollen just like the fuzz on a bumble bee.

As the specialized beak and tongue of a hummingbird indicates, many species of our feathered friends also act as important pollinators. Beyond hummingbirds, 920 species of bird are known to spread pollen between flowers, and are estimated to account for five percent of flower fertilization where they live. In more isolated environments, like islands, that number goes up, with birds being responsible for at least ten percent of flower pollination.

No need to fly to flowers

The success of pollinating bees, bats and birds may suggest that flight is somehow necessary to pollinate a flower, but that’s not the case. Any animal that wants to sip nectar without destroying the flower that produced it can potentially act as a pollinator, which has lead to at least 85 plant species around the world that get regular visits from non-winged mammals. Mice, squirrels, possums and lemurs may all stick their noses into flowers enough to transport pollen. Even without fur, bluetail day geckos (Phelsuma cepediana) can act as pollinators, carrying sticky pollen on the tips of their noses.

As humans become more appreciative of how insect pollinators help keep ecosystems alive, this research shows that we need to also consider the bigger-bodied pollinators as well. As policies and even substitutes are being developed to help protect creatures we associate with plants humans grow on farms, we need to make sure the wider range of pollinators around the world are protected as well. After all, some of these pollinators have become very adept at their sticky, hairy line of work, and won’t be easily replaced.

Source: Lizards, mice, bats and other vertebrates are important pollinators too by Ecological Society of America, Phys.org

On April 15th, 2018 we learned about

Staged speeches find nuances in the stressful side of seeing smiles

A smile is supposed to always be a sign of good news, but that may be biased towards the person doing the smiling. A big grin communicates a smiler’s happiness, boosts their mood and may convince them of other people’s happiness as well. On the other hand, while nobody wants to be scowled at, it turns out that people don’t always find it pleasant to be on the receiving end of a happy face. Depending on context, someone else’s smile can even be a source of stress.

Aside from the uncontrollable grin you have in response to personal enjoyment, there are three major types of social smiles. These smiles may be tied to a person’s impression of an event, but are largely meant to communicate a message to another individual. As their name indicates, rewarding smiles are meant to provide positive feedback to someone, encouraging their activity. Affiliation smiles are meant to build relationships, or at least show an attempt to relate to another individual. Dominant smiles are the least friendly of the three, as they’re sort of a passive aggressive way to remind someone of the smiler’s social superiority.

How friendly are those faces?

It’s not hard to imagine which of these smiles is the most pleasant to receive, but researchers needed to quantify the effects of these social interactions before they could draw conclusions about how they work. As a test, volunteers were asked to give a short speech, then shown reactions from “judges” via video. Judges were actually prerecorded, and were really just there to flash different types of smiles to the test participants so that their levels of the stress hormone cortisol could be measured. In every case, cortisol levels went up in the test participants, even when seeing a rewarding smile. However, the dominant smile triggered the biggest response, raising cortisol levels three-times higher than other facial expressions.

The fact that a dominant smile was unconsciously perceived as slightly threatening may not be surprising. There was an odd twist with test participants that suffered from social anxiety disorders or depression though. The type of smile didn’t seem to make much of a difference to these people one way or the other. Being less responsive to unwanted dominant smiles may sound like a benefit, but this suggests that these emotional disorders may limit people’s responsiveness to any social signals.

Source: The condescending smiles of others stress us out by Kimberly Hickok, Science

On April 12th, 2018 we learned about

Disregarded fossils and footprints help disprove dicynodonts’ assumed extinction

Around 70 years ago, two sets of fossilized footprints were found in South Africa. One was clearly a Triassic era dinosaur, but the other… didn’t make sense. The five-toed prints most closely resembled the feet of a dicynodont— a group of stocky, beaked-and-tusked herbivores that were widely believed to have gone extinct at the start of the Triassic period. While both sets of prints were acknowledged to contemporaneous of each other, the confounding dicynodont prints were basically ignored. The puzzling prints are finally getting explained though, largely thanks to modern paleontologists and an eccentric librarian from the 19th century.

Discovered but not formally described

Alfred “Gogga” Brown was employed as a librarian, postmaster and postman, but his real vocation was as a paleontologist. The self-taught scientist is credited with the discovery of 21 species of dinosaurs, reptiles and fishes, although he only published on paper on his work. Working on his own, Brown managed to collect a set of fossils in his adopted South Africa in the 1870s. They were never properly examined and described, as Brown had difficulty getting any paleontologists in Europe to take much interest in his work. As such, this batch of mystery fossils remained in storage at the Natural History Museum in Vienna, presumed to be fragments of a Triassic dinosaur.

Fortunately, Brown’s fossils have now been given a closer look and a new species name to boot. Pentasaurus goggai, named for Brown’s “Gogga” nickname, was found to be a close match for the mysterious footprints found decades ago. The animal was clearly a dicynodont synapsid, and as such is more closely related to mammals than dinosaurs or reptiles. They were widespread in their heyday, living all around the world until (mostly) going extinct at the end of the Permian period. However, this combination of trace fossil footprints and recovered skeletal fossils helps prove that some species managed to survive alongside the dinosaurs that were coming to dominate the planet’s terrestrial ecosystems.

Surviving in secret?

Strangely, Pentasaurus goggai is not be the only dicynodont to cause confusion by not going extinct when it was supposed to. In 1915, fossils of a dicynodont were found in Queensland, Australia, although their identity was controversial because they were found in Cretaceous period rock layers. That’s around 60 million years past these creatures’ supposed extinction, prompting vigorous tests in 2003. Taken together, it’s becoming increasingly clear that dicynodonts lived much longer than paleontologists once believed, although how they managed to hang on as their ecosystems were upended by new species isn’t totally clear yet. Maybe the next answer is still in museum’s collection somewhere.

Source: 60-year-old paleontological mystery of a 'phantom' dicynodont by North Carolina Museum of Natural Sciences, Science Daily