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Seagulls Are Carrying a Dangerous Superbug Through the Skies

A European Herring Gull (Larus argentatus) takes off.
A European Herring Gull (Larus argentatus) takes off.
Photograph by Ben Cranke

A superbug that’s resistant to the absolutely last-ditch antibiotic colistin has been reported in seagulls on two continents—pinpointing one way, though almost certainly not the only way, that this dangerous drug resistance is moving around the world.

Since last November, when researchers in England and China announced the discovery of bacteria able to survive colistin, there has been an explosion of people looking for that resistance, and finding it. Scientists have published almost 100 reports of colistin resistance—known as MCR and conferred by a gene that’s been dubbed mcr-1—in almost two dozen countries.

It has been found in human patients, including a woman in the United States in May; in livestock, which get the drug on intensive farms, and are probably the original source of the problem; and even in pets.

Now, in letters to the Journal of Antimicrobial Chemotherapy, two research teams in Lithuania and Argentina report that they trapped birds and swabbed their butts, or scooped up seagull droppings, and found the resistance-conferring gene in E. coli being carried by two species: herring gulls in Lithuania (Larus argentatus) and kelp gulls in Argentina (Larus dominicanus). 

Both teams think the birds probably picked up the resistant E. coli by eating garbage, which may have contained sewage or medical waste. (The organisms in the South American gulls also contained another important type of antibiotic resistance, known for short as ESBL.)

This isn’t the first time that gulls have been identified as possible carriers of antibiotic-resistant bacteria. In 2011, French researchers found multi-drug resistant E. coli in seagull droppings in Miami Beach, and those researchers and others earlier found resistant bacteria in gulls in Portugal, France, Russia, and Greenland.

The point in all those stories, as well as in the new reports, is that gulls migrate, from hundreds to thousands of miles depending on the species—so they could serve as a vehicle for carrying resistant bacteria somewhere new.

Gulls migrate, from hundreds to thousands of miles, so they could serve as a vehicle for carrying resistant bacteria somewhere new.

“The lifestyle of gulls allows them to carry and disseminate pathogenic and resistant microorganisms despite country borders,” the Lithuanian researchers say in their report. “Water contaminated by feces of birds should be foreseen as an important risk factor for transmission of resistant bacteria.”

The undetected movement of bacteria is especially important in the case of MCR, because the discovery of colistin resistance is truly alarming. Colistin is an old drug that medicine consigned to the back of the shelf in the 1950s because it is toxic, and only recently started using again because so many other antibiotics have been undermined by overuse in medicine and agriculture.

The gene that creates colistin resistance is on what is called a plasmid, a loop of DNA that isn’t bound up in chromosomes but can move easily between bacteria. That has scientists worried that the gene could move into disease organisms that already possess resistance to other antibiotics, creating a superbug that would be completely untreatable.

Kelp gull (Larus domicanus) perched on rock, Caldera, Chile.
Kelp gull (Larus domicanus) perched on rock, Caldera, Chile.
Photograph by Chris Mattison

So far, mcr-1 has been found in the United States three times: in two stored samples from slaughtered pigs that were stashed in a U.S. Department of Agriculture database, and in a 49-year-old woman in Pennsylvania, not identified by name, who went to a clinic for help with a urinary tract infection.

At a meeting Tuesday afternoon in Washington, D.C., of the Presidential Advisory Council on Combating Antibiotic-Resistant Bacteria, federal officials relayed that the woman has recovered from her infection, but still continues to carry the highly resistant bacterium in her system. Dr. Beth Bell, director of the National Center for Emerging and Zoonotic Diseases at the Centers for Disease Control and Prevention, also said that 99 of the woman’s family members and close contacts have been checked, and none of them are carrying bacteria containing mcr-1, reinforcing the mystery of how the resistant bacteria reached her.

Bell and representatives of the U.S. Department of Agriculture said the gene remains rare in the U.S.: The CDC has checked more than 55,000 stored samples collected from patients, animals, and food, and the USDA is checking 2,000 additional samples that it has stored. So far, that search has revealed only the two samples from pigs that were slaughtered in Illinois and South Carolina.

The officials commenting Tuesday agreed that there may be no way of tracing the path that MCR took to reach the U.S.—the bacteria may have spread from another person, or on food—and that the key thing now is to build surveillance systems that alert health planners as it moves.

“The good news is we found it,” observed Dr. Martin Blaser, a professor of medicine and microbiology at NYU Medical Center and chair of the Presidential council. “The bad news is, it’s here.”

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Surprising History of Glowing Fish

Black Dragonfish (Idiacanthus).
Black Dragonfish (Idiacanthus).
Photograph by Matt Davis

During the Cretaceous period, while flowers and tyrant dinosaurs were spreading over the land, and pterosaurs and birds were taking over the skies, in the oceans, fish were starting to glow.

Today, some 1,500 fish species are bioluminescent—able to make their own light. They have luminous fishing lures coming out of their heads, glowing stripes on their flanks, bright goatees dangling from their chins, flashing headlamps beneath their eyes, or radiant bellies that cancel out their silhouettes to predators watching from below.

They evolved their glow in a variety of ways. Some came to generate it on their own, through chemical reactions within their own cells. Others formed partnerships with luminous bacteria, developing organs for housing these microscopic beacons.

Despite the obvious diversity of bioluminescent fish, no one knew exactly how often these animals evolved their self-made light. “We thought it might be a dozen or so just by eyeballing a list,” says Matthew Davis from St. Cloud State University, “but the actual number was considerably higher.”

Together with John Sparks and Leo Smith, Davis built a family tree of ray-finned fish—the group that includes some 99 percent of fish species. By marking out the bioluminescent lineages, they report Wednesday in the journal PLOS ONE that these animals independently evolved their own light at least 27 times.

Illuminated Netdevil (Linophryne arborifera). Credit: Leo Smith
Illuminated Netdevil (Linophryne arborifera). Credit: Leo Smith

Of those 27 origins, 17 involve partnerships with glowing bacteria, which the fish took up from the surrounding water. Deep-sea anglerfishes housed the microbes in their back fins, which they transformed into complex lures. Ponyfishes kept the microbes in their throats, and controlled the light they produced by evolving muscular shutters and translucent windows.

But to Steven Haddock from the Monterery Bay Aquarium Research Institute, these partnerships are fundamentally different from cases where fish evolved their own intrinsic light. “If one species of bacteria evolves the ability to glow, then is eaten and proliferates in the guts of four different fishes, you could argue that bioluminescence evolved once in the bacterium,” he says. “To me, this is much less interesting than fishes that have their own chemical and genetic machinery.”

Those intrinsic light-producers have come to dominate the open oceans. There are around 420 species of dragonfishes, most of which have long bodies and nightmarish faces armed with sharp teeth. They include the bristlemouth, the most common back-boned animal on the planet; hundred of trillions of them lurk in the deep ocean. The lanternfishes are similarly prolific; the 250 or so species account for around 65 percent of the fish in the deep sea by weight. “They’re among the most abundant vertebrates on the planet in terms of mass, but the average person doesn’t know anything about them,” says Davis.

Silver Hatchetfish (Argyropelecus). Credit: Leo Smith
Silver Hatchetfish (Argyropelecus). Credit: Leo Smith

These groups aren’t just diverse, but unexpectedly so. In the relatively short time they’ve been around, they’ve accumulated far more species than is normal, and far more so than lineages that got together with glowing bacteria. Why?

Davis thinks it’s because they can exert greater control over their light. While ponyfishes have to rely on body parts that obscure the continuous glow of their microbes, lanternfishes and dragonfishes can turn their glows on or off, using nerves that feed into their light organs. That means they can flash and pulse. They can use their light not just to lure prey or hide from predators, but to communicate with each other.

Many scientists think that deep-sea fish could use bioluminescence as badges of identity, allowing them to recognises others of their own kind and to mate with partners of the right species. This might also explain why these fish became so extraordinarily diverse, in an open world with no obvious features like mountains or rivers to separate them.

“Biodiversity in the deep sea used to be viewed as somewhat of a paradox given the apparent lack of genetic barriers,” says Edie Widder from the Ocean Research and Conservation Association. Davis’s study hints at an answer. After evolving their own light, some fish may have effectively built luminous towers of Babel—different flashing dialects that split single communities into many factions. (Something similar may have happened among electric fish in the rivers of Africa.)

The same story applies to sharks. They’ve evolved bioluminescent at least twice, and these luminous species account for 12 percent of the 550 or so species of shark. And the groups whose light organs allow them to communicate with each other seem to be exceptionally diverse. As Julien Claes from the Catholic University of Louvain told me last year, “They’re some of the most successful groups of sharks. We discover new ones every couple of years.”

So forget great whites and makos, salmon and tuna, clownfish and angelfish. The most common and diverse fish in the world are the obscure ones that you probably haven’t heard about, swimming somewhere in the open ocean, basking in their own glow.

 

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This Squid Has Glowing Eyeshadow That Acts Like An Invisibility Cloak

Galiteuthis
Galiteuthis. Credit: MBARI

The oceans of the world are home to animals that render themselves invisible with glowing eyeshadow.

They’re called glass squid and, as their name suggests, they are largely transparent. They’d be impossible to see in the darkness of the open ocean were it not for their eyes—the only obviously opaque parts of their bodies.

These animals live between 200 and 1000 metres below the ocean surface, where water is mostly dark. Still, some sunlight penetrates to these depths, and this light is hundreds of times brighter than anything reflected horizontally or upwards. As such, any predator looking upwards at a glass squid would see the squid’s eyes in dark silhouette against a relatively light background.

To hide itself, a glass squid uses a trick that’s common among many oceanic animals: counter-illumination. Two organs under its eyes, known as photophores, give off a dim light, which perfectly matches the weak light coming from the surface. Their glow cancels out the squid’s silhouette so that, from below, instead of just being mostly invisible, it is completely invisible.

It helps that the glass squid’s eyes stick out from the side of its head, and are controlled by powerful muscles. No matter where the squid’s body is pointing, its gyroscopic eyes always stay in the same position, with the light-producing photophore beneath them.

But that still leaves a significant problem. Without any guidance, light would leave the photophore in every direction, making the squid hard to see from directly below, but very conspicuous from other angles. Its glowing invisibility cloak would also be a beacon, were it not for yet another cunning anatomical feature.

Amanda Holt and Alison Sweeney from the University of Pennsylvania have now reported in the Journal of the Royal Society Interface that a glass squid’s photophore consists of long, skinny cells that are shaped like hockey sticks—they run parallel to the eye, and then take a sharp downward turn. The walls of these cells are lined with reflective proteins that turn them into living optic fibres. They channel the photophore’s light along their length and then downwards, into the ocean’s depths.

“They’re a way of building a literal pipe for light,” says Holt.

But wait, there’s more!

When the duo first saw the fibres, they “thought it was going to be straightforward and boring,” says Sweeney. “Oh, there are little fibres. That’s cute. We’ll describe how they work and move on.” But when they looked more closely, they noticed that the fibres are really leaky. That is, they’re not perfectly reflective. A little light always pours out along their length.

They don’t have to be like that. A few easy structural changes would turn them into perfect light guides. Instead, “they’re really inefficient,” says Sweeney. “We struggled with that for a while, before realising: Oh, that’s part of the point.”

In the deep ocean, most light comes from directly above, but a small fraction still travels at oblique angles. So the squid’s counter-illuminating light also needs to work in many directions. That’s why the photophore fibres are leaky. They’re like the diffusers that you can stick on a camera to spread the light from a flash over a large area.

Holt confirmed this by creating simulating of the fibres and calculating how much light they send sideways and downwards. She also calculated the light levels in the squid’s mid-water habitat and, again, calculated the amount of light travelling sideways and downwards. The two ratios matched.

“I remember sitting in my office comparing the two, and my jaw dropped,” says Sweeney. “I thought there must have been a mistake and we couldn’t possibly have been that lucky the first time round. But we were.”

So the glass squid’s photophores are omnidirectional invisibility cloaks. They obscure the animal’s eyes by perfectly matching the light coming in from every direction (at least, in the lower half).

The squid shows how imperfections can actually be a good thing—a lesson that, according to Sweeney, engineers should pay attention to. “Over and over in biology, we see that evolution harnesses disorder in very clever ways to make better devices than what you’d get with highly ordered structures,” she says. “Thinking [about this] will help engineers to leverage the disorder in their systems rather than trying to get rid of it.”

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See the Ugly Beauty That Lives in a Toxic Cave

Norman Pace collects samples of a microbial mat.
Microbiologist Norman Pace collects a sample of a brainy-looking mat made of microbes (called a vermiculation) that coats the ceiling of Sulphur Cave.
Photograph by Norman R. Thompson

Lurking below the quaint ski town of Steamboat Springs, Colorado, lies a cave belching deadly gases. Its ceiling is dotted with snottites, dangling blobs that look like thick mucus and drip sulfuric acid strong enough to burn holes through T-shirts. And the whole place is covered in slime.

So why would anyone want to go there?

“Being in the cave reminded me of being inside a huge organism—as if I had been swallowed by some gigantic, alien monster from deep in the ocean or from outer space,” says photographer Norman Thompson.

Thompson joined a small group of scientists who are among the few people to ever explore Sulphur Cave, and who found it eerily beautiful, and brimming with strange life. As shown in National Geographic’s exclusive video below, along with spiders and insects, the cave holds sulfur-breathing microbes and a new species of blood-red worm.

EXCLUSIVE VIDEO: Clumps of newly discovered blood-red worms thrive in Sulfur Cave, which contains levels of toxic gases so lethal that any human who enters unprotected could quickly die.

“In a sense, we really were inside of an organism,” Thompson says, “or perhaps more accurately, an ecosystem. Because the cave is a colony of organisms, living together in a lightless ecosystem, powered not by sunlight, but by the sulfur coming from deep within the Earth.”

Inside the Belly

To enter the 180-foot-long (54 meters) cave, the intrepid scientists had to squeeze into a pit entrance, a hole in the ground that skiers might glide right past. And if you happen to visit without special equipment, you ought to glide past. Otherwise, the cave’s gases could knock you unconscious in a jiffy.

“It’s sort of foreboding,” says David Steinmann, a cave biologist at the Denver Museum of Nature and Science. “You have to climb and crawl down a wet muddy slop that’s stinky and smells like rotten eggs.”

A snottite found in a sulphur cave.
Snottites are thick, mucus-like blobs formed by bacteria growing in a sulfur cave.
Photograph by Norman R. Thompson

“It’s belching toxic gases,” Steinmann says, “and in the winter you can see steam coming out. You have to stoop down and squeeze through to get into the first room. Once you’re in there, it’s totally dark.”

But when the team brought in lights, they found that the cave is also lovely, in its own way. Crystals made of gypsum glitter on walls, and a small stream washes across the floor. Long tendrils made of more microbial colonies wave in the water’s flow.

Thompson photographed the cave twice, entering only after scientists had aired out the crevice using large fans—appropriately, the kind normally used to flush out underground sewers. “Even with the poisonous air flushed out by the fan, the cave still stunk of sulfur,” he says.

Such sulfur-filled caves are rare, with some found in Mexico and Italy. The high levels of sulfur that create the gas in Colorado’s Sulphur Cave come from deep within the earth. The cave is formed in travertine, a type of stone formed by deposits from streams and mineral springs.

Hydrogen sulfide gas, which gives the cave its rotten-egg smell, can be deadly at high concentrations. Yet life thrives inside the cave despite both the hydrogen sulfide and carbon dioxide up to four times levels that could kill a human.

Wormy Wonders

The biggest surprise was the blood-red worms found in the cave. “There’s a hell of a lot of worms in there!” says Norm Pace, emeritus professor of microbiology at the University of Colorado Boulder.

Worms in Sulphur Cave, Steamboat Springs, Colorado. These worms are believed to live on the chemical energy in the sulfur in the cave, similar to the way tube worms live in a world without light at the bottom of the ocean. Also visible on the left side of the image are streamers—colonies of microorganism, similar to those seen in hot springs in Yellowstone National Park. Photograph by Norman R. Thompson
These worms in Colorado’s Sulphur Cave are believed to live on the chemical energy in the sulfur in the cave, similar to deep-ocean tube worms. On the left are streamers—colonies of microorganisms similar to those in hot springs in Yellowstone National Park.
Photograph by Norman R. Thompson

The small worms live clumped together on the cave floor, where they’re probably making a living by grazing on the bacteria growing in wet spots, Pace says.

They’re also intensely red, much like the famous Riftia worms found at deep-sea vents, which are also rich in hydrogen sulfide. Pace has studied life in the vents and expected the cave ecosystem to be similar. It wasn’t, exactly. The ocean worms have special structures called trophosomes filled with bacteria that are able to live on hydrogen sulfide; essentially they “breathe” it. The worms rely on the bacteria to do this, so Pace was surprised that so far, the team hasn’t found a special home for bacteria inside the Sulphur Cave worms.

As for the cave worms’ bright red color, it probably comes from high levels of hemoglobin and related compounds that protect the worm from hydrogen sulfide. Steinmann and his colleagues described the worms this year in the journal Zootaxa.

They named it Limnodrilus sulphurensis, in honor of the sulfur that powers the base of the food chain in this otherwise deadly environment.

“It took over a year for the sulfur smell to gradually air out from my cave coveralls,” Thompson says. But would he go back? He’s still drawn by its strange beauty he says, so yes— “in a heartbeat.”

 

Correction: The cave is 180 feet long, not deep. This has been updated, and I  deleted a sentence about organic matter in the cave’s travertine—the cave’s sulfur comes mainly from geothermal activity, with microbial breakdown of organic matter as an additional, but minor, source. A clarifying sentence has been added. —EE (updated 6/15)

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How This Fish Survives in a Sea Cucumber’s Bum

Picture of a leopard sea cucumber excreting cuvierian organs, which look like white streamers, for defense
A leopard sea cucumber excretes its organs for defense. Photograph by WaterFrame, Alamy
Photograph by WaterFrame, Alamy

In 1975, Victor Benno Meyer-Rochow was diving off the Banda Islands in Indonesia, when he collected a leopard sea cucumber—a cylindrical relative of starfish and sea urchins. It was a large and stubby specimen, 40 centimetres long (16 inches) and 14 centimetres wide. He dropped it in a bucket of water, which he placed in a refrigerated room.

Sometime later, a slender, eel-like fish swam out of the sea cucumber’s anus.

It was a star pearlfish, and it wasn’t alone. Another wriggled out. And another. After ten hours, 14 pearlfish had evacuated the animal’s bum, each between 10 and 16 centimetres long. Another one stayed inside.

There are many species of pearlfish. Some live independently, but several make their homes in the bodies of shellfish, starfish, and other marine animals. Indeed, they got their name after one individual was found inside an oyster, dead and embedded within mother-of-pearl.

But sea cucumbers are their most infamous hosts. Having found one by following its smell, a pearlfish will dive into the anus headfirst, “propelling itself by violent strokes of the tail,” according to Eric Parmentier. If the sea cucumber objects and closes down its anus… well, it still has to breathe.

Oh yeah, sea cucumbers breathe through their anuses. By rhythmically expanding and contracting their bodies, they drive water through the anal opening and into a branching, lung-like structure called the respiratory tree. This process creates gentle currents that a pearlfish can use to find its hosts. It also creates a vulnerability, because a sea cucumber that’s clenching its butt is also holding its breath. When it exhales, as it eventually must, it dilates its anus, allowing the pearlfish to thread itself in. This time, it goes tail-first, bit by bit, breath by breath.

Some species just use the sea cucumbers as shelters. But the Encheliophis pearlfishes are full-blown parasites that devour their host’s gonads from within.

Pearlfish are typically found alone, and adults have been known to kill rivals that try to infiltrate the same host. Still, as Meyer-Rochow found, the fish can sometimes be more sociable—or at the very least, tolerant. No one knows why. It’s possible that when sea cucumbers are rare, the fish are forced to share a host. Alternatively, they could have gathered to breed. “If indeed the 15 fish entered for sexual reasons, one cannot help but think of the orgy that must have taken place inside the sea cucumber,” Meyer-Rochow says.

These anal abodes aren’t easy places to live.

These anal abodes shelter pearlfish from predators, but they aren’t easy places in which to live. Sea cucumbers produce bitter toxins called saponins that punch small holes in the membranes of cells. These chemicals ought to be especially destructive towards fish gills, whose cells come in thin, sensitive layers with a large surface area.

Pearlfish should be especially vulnerable, since they are literally swimming inside the saponin-producing structures. And yet, when Igor Eeckhaut exposed various fishes to sea cucumber saponins, the pearlfish survived 45 times longer than other species. How do they cope?

Sea cucumbers resist their own poisons because their cell membranes comprise special chemicals that interact less strongly with saponins. But Lola Brasseur from Eeckhaut’s team found that pearlfishes don’t use such fancy chemistry. Nor do they have any tricks for detoxifying the saponins.

Instead, they rely on mucus, which they secrete onto their skins. The mucus helps to lubricate them on their way into their hosts, but it also acts as a physical barrier against the toxic saponins. It’s especially effective because the pearlfishes make so much of it—six to ten times more than other fishes that have no interest in sea cucumber bums.

Of course, none of this explains why the sea cucumbers don’t use their most effective defence. When threatened, they can expel their respiratory trees at their attackers, relying on their regenerative powers to re-grow the lost organ.

Why, then, do they never evict their pearlfish lodgers in this way? No one knows.

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How to Survive a Fast, Venomous, Flesh-Destroying Snake

The boy was thirteen years old when, while hunting for bush rats, he stuck his hand down the wrong hole. He was bitten by a saw-scaled viper. The boy’s hand swelled up and his skin turned white. He started bleeding from huge open gashes in his knuckles and arms. Worse still, the flesh in his hand started rotting.

The saw-scaled viper or carpet viper, Echis carinatus, Photograph by imageBROKER, Alamy
The saw-scaled viper or carpet viper, Echis carinatus, Photograph by imageBROKER, Alamy

Kempaiah Kemparaju from the University of Mysore in India shows me photos of the venom’s handiwork, and they’re hard to stomach. By the final image, the boy’s hand is a red, pulpy mess, and two fingers are missing. It looks like he reached into some kind of industrial machine.

The graphic images are, sadly, commonplace. Most snakes are harmless to humans, and even dangerously venomous ones are unlikely to bite us or to inject much venom. But the saw-scaled viper is a rare exception. It’s aggressive and hard to spot. It’s common to parts of the world that are densely populated by humans. And it has a potent venom. Toxins in the venom can break down the membranes that line our blood vessels, and max out our ability to clot, leading to catastrophic bleeding.

But the venom doesn’t just kill; it destroys.

It devastates the tissues around the site of the bite, so that even if people survive, they can still lose fingers, toes, or entire limbs. It’s estimated that around 125,000 people die from snakebites every year, but around 400,000 more face amputations. Antivenoms don’t help. They consist of large antibodies that are too big to effectively move from the blood into tissues that are being attacked. They save lives, but not limbs.

But we’re a little closer to a solution because Kemparaju and his colleagues, Gajanan Katkar and Kesturu Girish, have finally discovered how the viper’s venom wreaks so much havoc.

The team knew that the immune system reacts to viper venom by deploying white blood cells to the site of a bite. They suspected that some of these cells—the macrophages—might be inadvertently damage tissue, so they started isolating them. In the process, they snagged another kind of white blood cell, too—the neutrophils. What the hell, they thought. Might as well study the neutrophils too.

Good thing they did.

Neutrophils can sacrifice themselves to kill microbes by bursting open and releasing a tangled mesh of their own DNA. These webs, which are loaded with antimicrobial molecules, immobilise and kill invading cells. Rather aptly, they’re called neutrophil extracellular traps, or NETs.

When Kemparaju’s team saw the DNA threads under a microscope, they realised that neutrophils were also releasing NETs in the presence of viper toxins. But there, they do harm. The mesh blocks blood vessels and trap venom toxins at the site of the bite, where they attack local tissues. Those tissues also starve of oxygen, quickening their demise. Indeed, when the team injected viper venom into mice with low levels of neutrophils, the rodents succumbed to the venom but didn’t show any signs of tissue damage.

This leaves an unenviable choice. The actions of the neutrophils destroy tissue. But without them, the toxins circulate all over the body, damaging more organs and potentially killing the victim outright. The latter, incidentally, is what cobra venom does. It contains an enzyme called DNase that slices through the NETs and releases the trapped toxins.

Saw-scaled vipers lack DNase, which is probably a good thing on balance. “If the venom did have DNase activity, the systemic toxins along with the tissue-degrading enzymes would damage vital organs in no time, and a victim’s chances of survival would have been feeble,” says Kemparaju. It’s like this, he says: “Instead of life, you give your limb.”

But there might be a way to save both life and limb.

When the team injected mice with venom and DNase at the same time, the rodents died more quickly than they did with venom alone. But if the team waited for an hour or two before injecting the DNase, they prevented tissue damage without reducing the rodent’s odds of survival. “With our mice, we have achieved 100 percent success,” says Kemparaju. “Even if you administer the DNase three hours after the venom, you can prevent the loss of limb.”

“The results are very exciting, as they open up a potential new therapy for treating the debilitating, horrific, and destructive effects of certain snake venoms,” says Nicholas Casewell at the Liverpool School of Tropical Medicine. Still, the team must run clinical trials to ensure that DNAse treatments are safe and effective in people. Timing is everything, and the enzymes can do more harm than good if given at the wrong moment. And people would still need antivenoms to deal with the toxins already circulating in their blood.

“It will also be very interesting to see whether DNases will also reduce the local tissue effects caused by other snakes, such as puff adders and spitting cobras, thereby providing a generic treatment,” adds Casewell.

Paleo Profile: The Giant, Bone-Crushing Weasel

Three views of Megalictis: restoration, skull reconstruction, and original skull. Art by Adam Hartstone-Rose.
Three views of Megalictis: restoration, skull reconstruction, and original skull. Art by Adam Hartstone-Rose.

Some beasts catch you by surprise. I’m not talking about ambush predators – though such a statement would hold true – but rather prehistoric mammals whose very existence comes as something of a shock. The latest to make me go “What the hell?” is an enormous weasel that used to prowl western North America.

Paleontologist William Diller Matthew named carnivore Megalictis ferox way back in 1907. The mammal’s teeth and osteology clearly showed it to be a cousin of martens and stoats, yet their dimensions “indicate an animal which may best be described as a gigantic wolverene [sic], equaling a jaguar or a black bear in size.” And given that cats were meek little things at the time Megalictis lived, paleontologists thought that this weasel had evolved to take on a lion-like lifestyle during North America’s long Cat Gap.

But now paleontologist Alberto Valenciano and colleagues have discovered that Megalictis was no feline wannabe. Through a new analysis of previously-undescribed skull material, the researchers not only refine the evolutionary relationships of America’s giant weasels, but they also make the case that the teeth and jaws of Megalictis were more like those of hyenas and some deep-jawed dogs than to cats. In other words, this huge weasel was a bone-crusher.

Additional Megalictis skull material. From Valenciano et al., 2016.
Additional Megalictis skull material. From Valenciano et al., 2016.

Fossil Facts

Name: Megalictis ferox

Meaning: The entire name translates roughly to “fierce giant wolverine.”

Age: Between 22.7 and 18.5 million years ago.

Where in the world?: South Dakota, Nebraska, and Wyoming.

What sort of critter?: A mustelid, or a member of the group that includes weasels and their relatives.

Size: Estimated as being about the size of a jaguar.

How much of the creature’s body is known?: The new study focused on skull material from several individuals, including a nearly-complete cranium and almost-perfect lower jaws.

References:

Matthew, W. 1907. A lower Miocene fauna from South Dakota. Bulletin of the American Museum of Natural History. 23 (9): 169-219

Valenciano, A., Baskin, J., Abella, J., Pérez-Ramos, A., Álvarez-Sierra, M., Morales, J., Hartstone-Rose, A. 2016. Megalictis, the bone-crushing giant mustelid (Carnivora, Mustelidae, Oligobuninae) from the Early Miocene of North America. PLOS ONE. doi: 10.1371/journal.pone.0152430

Previous Paleo Profiles:

The Unfortunate Dragon
The Cross Lizard
The South China Lizard
Zhenyuan Sun’s dragon
The Fascinating Scrap
The Sloth Claw
The Hefty Kangaroo
Mathison’s Fox
Scar Face
The Rain-Maker Lizard
“Lightning Claw”
The Ancient Agama
The Hell-Hound
The Cutting Shears of Kimbeto Wash
The False Moose
“Miss Piggy” the Prehistoric Turtle
Mexico’s “Bird Mimic”
The Greatest Auk
Catalonia’s Little Ape
Pakistan’s Butterfly-Faced Beast
The Head of the Devil
Spain’s Megatoothed Croc
The Smoke Hill Bird
The Vereda Hilarco Beast
The North’s Sailback
Amidala’s Strange Horn
The Northern Mantis Shrimp
Spain’s High-Spined Herbviore
Wucaiwan’s Ornamented Horned Face
Alcide d’Orbigny’s Dawn Beast
The Shield Fortress
The Dragon Thief
The Purgatoire River’s Whale Fish
Russia’s Curved Blade
The Dawn Mole
The Oldest Chameleon
The Wandering Spirit
Teyú Yaguá
New Caledonia’s Giant Fowl
The Giant Tarasque Tortoise

We Still Don’t Know What Killed the Biggest Shark of All Time

We just can’t let Carcharocles megalodon rest. From Peter Benchley’s JAWS to the dreck that regularly bobs up to the surface of basic cable “science” channels, we can’t seem to resist invoking the specter of a shark so large that it could easily engulf a person without a drop of blood spilled into the sea.

Art by Fernando G. Baptista; Research by Ryan T. Willians, Fanna Gebreyesus; Source: STEPHEN J. GODFREY, CALVERT MARINE MUSEUM
Art by Fernando G. Baptista; Research by Ryan T. Willians, Fanna Gebreyesus; Source: STEPHEN J. GODFREY, CALVERT MARINE MUSEUM

Despite our fascination with this enormous, extinct relative of today’s great white shark, there’s still a great deal we don’t know about the life and death of the biggest shark that ever lived. For starters, we still don’t know why the last of the megatooths died over 2.5 million years ago.

In the entire history of cartilaginous fish, Carcharocles megalodon was a huge success story. And that’s not just because of the predator’s size and inferred ferocity. This species patrolled the coasts of the Atlantic, Pacific, and Indian Oceans for about 20 million years. Few creatures can claim such a record. And that only makes the disappearance of the shark all the more puzzling.

Changes brought on by a cooling climate have been the focus of the traditional explanation for the monstrous shark’s demise. C. megalodon has often been thought of as a warm-water hunter, and so, the argument goes, as sea temperatures dipped at the end of the Pliocene the whales, seals, and other fatty mammals the shark relied upon migrated to chilled seas where the shark couldn’t follow. The pitiful selachian was simply left behind as cetaceans spouted off for the poles.

But was the great shark so restricted by temperature? To find out, paleontologist Catalina Pimiento and colleagues drew from the Paleobiology Database to analyze occurrences of C. megalodon over time in relation to climate.  Contrary to what had previously been thought, temperature probably didn’t freeze the shark into extinction.

Curator Jeff Seigel stands in the five–-foot mouth of a fossil shark jaw. The shark is called Carcharoles Megalodon and was large enough to swallow a small car. Photograph by Rick Meyer, Los Angeles Times, Getty
Curator Jeff Seigel stands in the five–-foot mouth of a fossil shark jaw. The shark is called Carcharoles Megalodon and was large enough to swallow a small car. Photograph by Rick Meyer, Los Angeles Times, Getty

The big picture looks something like this. During the shark’s early years, around 20 million years ago, C. megalodon primarily swam through waters of the northern hemisphere. Populations expanded around 15 million years ago to include every major ocean basin on the planet, the researchers write, but from there the sharks populations steadily declined.

All of this happened irrespective of climate. During times of major temperature spikes and dips, Pimiento and coauthors note, C. megalodon occurrences didn’t seem to show any direct response. Not to mention that the shark seemed fully capable of coping with a range of temperatures from 53 to 80 degrees Fahrenheit, and there have been waters in this range from the shark’s time until today. As Pimiento and coauthors write, “C. megalodon would have not been affected significantly by the temperature changes during the Pleistocene, Holocene and Recent.”

Populations of C. megalodon over time. From Pimiento et al., 2016.
Populations of C. megalodon over time. From Pimiento et al., 2016.

So if it wasn’t cooler waters, what drove the shark to extinction? There’s still no definitive answer. Even today, when we can witness species disappear, it’s often difficult to precisely retrace the road from the vanishing point back to the first signs of trouble. In the case of C. megalodon, though, Pimiento and coauthors have some ideas about possible killswitches.

Through hindsight, we can see that the road to extinction for the megatooth shark started in the middle of the Miocene. This coincided with two major events, as previously pointed out by paleontologist Dana Ehret as well as the authors of the new study. Against a background of crashing whale diversity during this time, the world saw the evolution of some stiff competition for C. megalodon: large sharks close to the ancestry of the great white and sperm whales that behaved and hunted more like today’s orcas. This trend continued only through the Pliocene, with fewer big baleen whales and an increasing array of predators that young megatooth sharks would have struggled against to get enough food down their throats. There was less food to go around for an expanding guild of predators who relied upon warm, blubbery prey.

The case isn’t closed yet, though. So much of what’s known about C. megalodon comes from teeth, the occasional vertebra, and some bite marks. Those pieces only reach so far in revealing the massive shark’s biology, including how much the fish actually relied on filter-feeding whales for food or the other predators it was striving against to survive.

We can be sure the megatooth shark is dead. The fish’s fossil record taps out by 2.5 million years ago, and we surely wouldn’t miss populations of fifty-foot-long sharks patrolling the global coastlines. But why the shark vanished is a secret still waiting to be dredged from the fossil record.

Reference:

Pimiento, C., MacFadden, B., Clements, C., Varela, S., Jaramillo, C., Velez-Juarbe, J., Silliman, B. 2016. Geographical distribution patterns of Carcharocles megalodon over time reveal clues about extinction mechanisms. Journal of Biogeography. doi: 10.1111/jbi.12754

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Birds on Islands Are Losing the Ability to Fly

Before the arrival of humans—and the rats, cats, and other predators that we brought—New Zealand was an idyllic haven for birds. Without ground-dwelling mammalian hunters to bother them, many of the local species lost the ability to fly. There’s the kakapo, a giant, booming parrot with an owl-like countenance; the takahe, weka, and other flightless relatives of coots and moorhens; a couple of flightless ducks; and, of course, the iconic kiwi.

Kakapo (Strigops habroptilus) at night, Codfish Island, New Zealand. Photograph by Stephen Belcher, Minden Pictures, Corbis
Kakapo (Strigops habroptilus) at night, Codfish Island, New Zealand. Photograph by Stephen Belcher, Minden Pictures, Corbis

These birds are part of a pattern that plays out across the world’s islands. Wherever predators are kept away by expanses of water, birds become flightless—quickly and repeatedly. This process has happened on more than a thousand independent occasions, producing the awkward dodo of Mauritius, the club-winged ibis of Jamaica, and the tatty-winged flightless cormorant of the Galapagos.

The call of the ground is a strong one, and it exists even when the skies are still an option. Natalie Wright from the University of Montana demonstrated this by collecting data on 868 species. She showed that even when island birds can still fly, they’re edging towards flightlessness. Compared to mainland relatives, their flight muscles (the ones we eat when we tuck into chicken breasts) are smaller and their legs are longer.

“Pretty much all island birds are experiencing these pressures to reduce flight, even if some can’t go to the extreme,” Wright says.

Her results show that flying isn’t a binary thing, with a clear boundary between taking to the air and staying on the ground. Instead, there’s a full spectrum of abilities between aeronautical swifts and shuffling kiwis, and island birds exist on all parts of that continuum. “None of the species I looked at were flightless or close to being truly flightless,” says Wright. “There’s no point where, all of a sudden, they have much smaller flight muscles.”

Her study began about 20 years ago, when her undergraduate advisor David Steadman started weighing the flight muscles of birds at the Florida Museum of Natural History. When Wright got her hands on the data set, she noticed that fruit doves had smaller flight muscles on islands that were further from the mainland. She then travelled to five natural history museums herself to examine more skeletons. For each one, she measured the long bones in the lower legs and the size of the breastbone—the latter revealed how heavy the bird’s flight muscles would have been in life.

Across nine major groups of birds, with a wide range of lifestyles, body shapes, and diets, Wright found the same trend. On smaller islands with fewer species, no mammalian predators, and fewer birds of prey, birds have repeatedly reallocated energy from forelimbs to hindlimbs, away from big flight muscles and towards longer legs.

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To her surprise, the trend even applied to hummingbirds, for whom flying is an inextricable part of life. Hummingbirds hover in front of flowers to drink nectar. A flightless hummingbird is a dead hummingbird. And yet, even though “islands hummingbirds look like hummingbirds when they fly, they were still reducing their flight muscles and evolving longer legs on islands without predators,” says Wright.

The same was true for kingfishers, flycatchers, tanagers, honeyeaters, and other groups that are extremely dependent on flight. Wright studied the Todiramphus kingfishers across 27 Pacific islands. “Members on islands with fewer than 20 species of birds, which don’t have any predators that can kill an adult kingfisher, have much smaller flight muscles and much longer legs than any members on larger and more populated islands,” she says. “They sit on perches and fly out to grab prey. Their foraging style requires flight, but they’re edging towards flightlessness.”

Why? It’s easy to see why a diving bird like a cormorant or a ground-dwelling one like a kakapo might lose its ability to fly when predators are absent. But why should a hummingbird or kingfisher, which flies all the time, sacrifice some of its aerial prowess?

Because flight muscles come with a cost. Even at rest, larger ones require more energy to maintain. So if birds can get away with smaller ones, evolution pushes them in that direction. Large flight muscles are especially useful when birds take off. That’s the most energetically demanding part of flying, and the bit that’s most important for escaping from ground predators. If such predators are absent, birds can take off at a more leisurely pace, and they can afford to have smaller (and cheaper) flight muscles. (This might also explain why they developed longer legs: they take off more by jumping than by flapping.)

Wright’s results suggest that island birds might be more vulnerable to introduced predators than anyone appreciated. Even those that can fly aren’t as good at it as their mainland counterparts. They may also help to explain why island birds diversify into such wondrous forms. When they settle in a remote landmass, even the flying ones might quickly lose the power they need to cross oceans and find new homes.

Islands, it seems, create birds that stay on islands.

Paleo Profile: The Giant Tarasque Tortoise

The shell of Taraschelon. From Pérez-García, 2016.
The shell of Taraschelon. From Pérez-García, 2016.

Giant, shelled reptiles hold a special place in our hearts, whether you prefer something as highbrow as the classical myth of the World Turtle or the wanton, city-stomping destruction of Gamera. Turtles and tortoises already have an ancient look to them, even when they’ve just hatched, and so the giant ones seem like the must be even more ancient and wise, as if they carry secrets from the days when the Earth was young.

In 1844, the French paleontologist Auguste Bravard described the shell of one such chelonian found in the Oligocene-age rock of southern France. Very little was known about even living tortoises at the time, so it made sense to attribute the two-and-a-half-foot-long shell to the same genus that encompassed many modern species, Testudo. And from there, the shell was almost entirely forgotten.

But now paleontologist Adán Pérez-García has gone back to that old shell and found it not only represents the largest tortoise of its time, but belonged to a distinct genus. From the shell excavated so long ago, Pérez-García has named the tortoise Taraschelon in reference to a shelled creature in French lore known as Tarasque. That’s the nice thing about turtles and tortoises – there are so many stories and legends about them that when you find a previously-unseen species, there’s always the opportunity to make something old new again. Now if we could only get one named for the Great A’Tuin.

A statue of Tarasque. Image from Wikipedia.
A statue of Tarasque. Image from Wikipedia.

Fossil Facts

Name: Taraschelon gigas

Meaning: Taras is short for Tarasque, a legendary creature with a turtle-like shell, while chelon means turtle or tortoise and gigas means “giant.”

Age: Around 30 million years old.

Where in the world?: Southern France.

What sort of critter?: A tortoise.

Size: The shell measures about two and a half feet long.

How much of the creature’s body is known?: A nearly-complete shell.

Reference:

Pérez-García, A. 2016. A new genus for ‘TestudoGigas, the largest European Paleogene testudinid. Journal of Vertebrate Paleontology. doi: 10.1080/02724634.2015.1030024

Previous Paleo Profiles:

The Unfortunate Dragon
The Cross Lizard
The South China Lizard
Zhenyuan Sun’s dragon
The Fascinating Scrap
The Sloth Claw
The Hefty Kangaroo
Mathison’s Fox
Scar Face
The Rain-Maker Lizard
“Lightning Claw”
The Ancient Agama
The Hell-Hound
The Cutting Shears of Kimbeto Wash
The False Moose
“Miss Piggy” the Prehistoric Turtle
Mexico’s “Bird Mimic”
The Greatest Auk
Catalonia’s Little Ape
Pakistan’s Butterfly-Faced Beast
The Head of the Devil
Spain’s Megatoothed Croc
The Smoke Hill Bird
The Vereda Hilarco Beast
The North’s Sailback
Amidala’s Strange Horn
The Northern Mantis Shrimp
Spain’s High-Spined Herbviore
Wucaiwan’s Ornamented Horned Face
Alcide d’Orbigny’s Dawn Beast
The Shield Fortress
The Dragon Thief
The Purgatoire River’s Whale Fish
Russia’s Curved Blade
The Dawn Mole
The Oldest Chameleon
The Wandering Spirit
Teyú Yaguá
New Caledonia’s Giant Fowl

Paleo Profile: New Caledonia’s Giant Fowl

A restoration of Sylviornis. From Worthy et al., 2016.
A restoration of Sylviornis. From Worthy et al., 2016.

Life gets weird on islands. Some species, such as elephants, shrink over time, while forms of life that are tiny on the mainland expand to unheard of sizes. Among the best examples of this Island Rule—which is really more of an Island Puzzle—are birds. Over and over again, islands have hosted populations of ground-dwelling, supersized birds, such as one hefty fowl that strutted around New Caledonia.

François Poplin named the bird Sylviornis neocaledoniae in 1980. Exactly what sort of avian it was, however, has been in dispute ever since then. Poplin considered the helmet-headed bird to be related to cassowaries and emus, while other experts suggested that Sylviornis was much closer to turkey-like megapodes. Then further analysis of the skull led other avian experts to put Sylviornis in its own special lineage, the Sylviornithidae, asserting that the turkey-like features of the birds bones were a case of convergence.

In order to sort through this tangle, paleontologist Trevor Worthy and colleagues had a look at about 600 bones of the bird’s body. What they found supported some earlier suggestions about where the bird nested in the greater avian family tree – Sylviornis was a stem galliform, or a relatively archaic member of the group that contains turkeys, pheasants, and chickens. And this might rule out Sylviornis as the answer to a New Caledonian mystery.

Strange earthen mounds on New Caledonia were thought to be the nests of the massive Sylviornis. But this connection relied on the idea that the big bird was a megapode, as these birds characteristically deposit warm their eggs in holes or little hillocks of soil to gain warmth from rotting vegetation, the earth, or some other outside source. Now that Worthy and coauthors have pushed Sylviornis further away from the megapodes, the idea that the mystery mounds were made by Sylviornis now seems less likely. The anatomy of the bird’s feet, the researchers conclude, was at best suited to scratching at the dirt as if it were a supersized chicken. Perhaps, as paleontologists scratch at the soil themselves, they’ll uncover more clues about the life and times of this long-lost fowl.

Some of the Sylviornis long bones examined in the study. From Worthy et al., 2016.
Some of the Sylviornis long bones examined in the study. From Worthy et al., 2016.

Fossil Facts

Name: Sylviornis neocaledoniae

Age: Over 5,500 years ago until about 3,000 years ago.

Where in the world?: New Caledonia

What sort of critter?: A bird related to landfowl like turkeys and pheasant.

Size: Over two and a half feet tall and more than 60 pounds.

How much of the creature’s body is known?: Thousands of individual elements from the skeletons of multiple individuals.

Reference:

Worthy, T., Mitri, M., Handley, W., Lee, M., Anderson, A., Sand, C. 2016. Osteology supports a steam-galliform affinity for the giant extinct flightless birds Sylviornis neocaledoniae (Sylviornithidae, Galloanseres). PLOS ONE. doi: 10.1371/journal.pone.0150871

Previous Paleo Profiles:

The Unfortunate Dragon
The Cross Lizard
The South China Lizard
Zhenyuan Sun’s dragon
The Fascinating Scrap
The Sloth Claw
The Hefty Kangaroo
Mathison’s Fox
Scar Face
The Rain-Maker Lizard
“Lightning Claw”
The Ancient Agama
The Hell-Hound
The Cutting Shears of Kimbeto Wash
The False Moose
“Miss Piggy” the Prehistoric Turtle
Mexico’s “Bird Mimic”
The Greatest Auk
Catalonia’s Little Ape
Pakistan’s Butterfly-Faced Beast
The Head of the Devil
Spain’s Megatoothed Croc
The Smoke Hill Bird
The Vereda Hilarco Beast
The North’s Sailback
Amidala’s Strange Horn
The Northern Mantis Shrimp
Spain’s High-Spined Herbviore
Wucaiwan’s Ornamented Horned Face
Alcide d’Orbigny’s Dawn Beast
The Shield Fortress
The Dragon Thief
The Purgatoire River’s Whale Fish
Russia’s Curved Blade
The Dawn Mole
The Oldest Chameleon
The Wandering Spirit
Teyú Yaguá

Paleo Profile: Teyú Yaguá

Teyujagua-skull
The skull of Teyujagua paradoxa. From Pinheiro et al., 2016.

Do a Google Image search for the word “Triassic” and you’re going to see variations of the same scene over and over again. Svelte little dinosaurs snap and squawk around an ancient lake or river, with the also-rans of their era – such as the armored aetosaurs and superficially-crocodile-like phytosaurs – shuffling through the undergrowth and basking at the water’s edge. Such vignettes are classic Triassic imagery, and yet they’re only a narrow view of one part of the opening chapter in the Age of Reptiles triology. There’s far more to the Triassic story than Coelophysis and its neighbors, with the latest wrinkle to the tale arriving in the form of a beautiful skull found in Brazil.

The fossil, described by paleontologist Felipe Pinheiro and colleagues, was that of an archosauromorph. This was a line of reptiles that first evolved back in the Permian, when the protomammals held sway, and underwent explosive diversification during the Triassic, eventually sprouting branches that would include dinosaurs, pterosaurs, and crocodiles.

Named Teyujagua paradoxa by the researchers, the 251 million year old animal lived just before the great reptilian radiation really took off. So while not necessarily the ancestor of the various lineages that would come later, Pinheiro and coauthors point out that the skull of Teyujagua is a significant part of the story given that it exhibits some characteristics of older forms of reptiles as well as novelties that would come to mark the “ruling reptiles” such as serrated teeth and an opening in the sidewall of the lower jaw. When you look at the skull of Teyujagua, you’re looking at a face that helped set evolutionary trends from the dawn of the Triassic until today.

A close-up of Teyujagua. From Pinheiro et al., 2016.
A close-up of Teyujagua. From Pinheiro et al., 2016.

Fossil Facts

Name:Teyujagua paradoxa

Meaning: The genus was named after Teyú Yaguá, a dog-headed lizard in Guarani mythology, while paradoxa underscored the “unusual” combination of characteristics.

Age: Around 251 million years ago.

Where in the world?: Southern Brazil.

What sort of critter?: An archosauromorph, or an ancient member of the lineage that includes dinosaurs, pterosaurs, crocodiles, and their relatives.

Size: The skull is about four and a half inches long.

How much of the creature’s body is known?: A nearly-complete skull and several neck vertebrae.

Reference:

Pinheiro, F., França, M., Lacerda, M., Butler, R., Schultz, C. 2016. An exceptional fossil skull from South America and the origins of the archosauriform radiation. Scientific Reports. doi: 10.1038/srep22817

Previous Paleo Profiles:

The Unfortunate Dragon
The Cross Lizard
The South China Lizard
Zhenyuan Sun’s dragon
The Fascinating Scrap
The Sloth Claw
The Hefty Kangaroo
Mathison’s Fox
Scar Face
The Rain-Maker Lizard
“Lightning Claw”
The Ancient Agama
The Hell-Hound
The Cutting Shears of Kimbeto Wash
The False Moose
“Miss Piggy” the Prehistoric Turtle
Mexico’s “Bird Mimic”
The Greatest Auk
Catalonia’s Little Ape
Pakistan’s Butterfly-Faced Beast
The Head of the Devil
Spain’s Megatoothed Croc
The Smoke Hill Bird
The Vereda Hilarco Beast
The North’s Sailback
Amidala’s Strange Horn
The Northern Mantis Shrimp
Spain’s High-Spined Herbviore
Wucaiwan’s Ornamented Horned Face
Alcide d’Orbigny’s Dawn Beast
The Shield Fortress
The Dragon Thief
The Purgatoire River’s Whale Fish
Russia’s Curved Blade
The Dawn Mole
The Oldest Chameleon
The Wandering Spirit

Most Dinosaur Species Are Still Undiscovered

Just about every two weeks, we meet a new dinosaur species. Some come fresh from the desert. Others have been hiding in museum collections for decades, or were misidentified as different species. However they’re found, though, dinosaurs are stomping out onto the public stage at a greater rate than ever before. Just last week, for example, paleontologist Hans-Dieter Sues and colleagues named a new, tiny tyrannosaur that once scampered around prehistoric Uzbekistan.

And if the latest estimate is correct, we’re not even close to hitting Peak Dinosaur yet.

We’ll never know precisely how many non-avian dinosaurs roamed the planet between their origin 235 million years ago and their decimation 66 million years ago. The fossil record is not complete—animals that lived in upland environments scoured by erosion had poor chances of being preserved, for instance—and that’s not accounting for sampling bias dictated by researcher interests and what field specialists can actually remove from the rock.

Even then, most of what we know about dinosaurs comes from their skeletal remains. This lets us tell the difference between Tyrannosaurus and Triceratops, but, like some modern birds and reptiles, some non-avian dinosaur species may have differed only in color, geographic range, or other squishy features that we just don’t have access to. Even if we had the bones of every single dinosaur, we’d still probably underestimate the true number of species.

Still, given these caveats, University of Oslo researchers Jostein Starrfelt and Lee Hsiang Liow have created a new model they call TRiPS to estimate how many dinosaur species were around during the Triassic, Jurassic, and Cretaceous chapters of their history.

Visitors passing by the skeletons of dinosaurs in the Humboldt Museum fur Naturkunde in Berlin, Germany. Photograph by VPC Photo, Alamy
Visitors passing by the skeletons of dinosaurs in the Humboldt Museum fur Naturkunde in Berlin, Germany. Photograph by VPC Photo, Alamy

Drawing from known dinosaur records in the Paleobiology Database, the researchers extended the known record into estimations of origin and extinction for dinosaur species throughout their history and included a simulation of how likely it’d be for species to enter the fossil record.

In all, Starrfelt and Liow write, the heyday of the dinosaurs saw the comings and goings of about 1,936 different species. About half this count are expected to be theropods—the lineage that includes T. rex and birds—with the rest split between the long-necked sauropodomorphs and ornithischians such as the armored, horned, and duckbilled dinosaurs.

Starrfelt and Liow acknowledge that they’re dealing with estimates and that refinements will likely alter their dinosaur count. But, for a first run, the results came out similar to what’s been proposed before. In 2006 paleontologists Steve Wang and Peter Dodson estimated that around 1,844 genera of dinosaurs lived during the Mesozoic. While the categories are different—a genus can contain multiple species, like Triceratops horridus and Triceratops prorsus—many dinosaurs described so far are what paleontologists call monospecific, or have only one species in a genus. This affects estimates drawn from the known span of dinosaur discoveries, and might be why the species count isn’t even higher.

The last time anyone did a major count, about eight years ago, paleontologists recognized about 648 valid genera and 675 species of Mesozoic dinosaur, including birds. Those numbers have continued to shift. In 2010, eight new dinosaur species were found in Utah alone, and debates over lumping genera or species continue, as tortured Torosaurus knows. And if the current estimates of dinosaur diversity are correct, discovery and debate will keep a frantic pace for decades to come. We’ve only just started to find all the dinosaurs, much less understand the lives of these impressive creatures.

Reference:

Starrfelt, J., Liow, L. 2016. How many dinosaur species were there? Fossil bias and true richness estimated using a Poisson sampling model. Philosophical Transactions of the Royal Society B. doi: 10.1098/rstb.2015.0219

Paleo Profile: The Wandering Spirit

The skull of Mupashi migrator. From Huttenlocker and Sidor, 2016.
The skull of Mupashi migrator. From Huttenlocker and Sidor, 2016.

There’s no foolproof way to avoid extinction. A disease, a global cold snap, an asteroid with a deadly trajectory – these are all things that every other species in the entire history of life hasn’t been able to foresee or plan for. One day the world changes, and only the lucky survive.

But there are a few ways that entire lineages of organisms have inadvertently made themselves resistant to extinction. One of the best, it seems, is to spread far and wide over the planet. At least then there’s a chance that some members of the family will persist in a refuge, able to stick it out through the worst of the extinction pulse.

This is just the sort of good fortune that was with the therocephalians. These were the “beast heads”, ancient protomammal relatives of ours that could be found all over the ancient Northern and Southern Hemispheres during the Permian period of Earth history. That distribution was helpful during the catastrophic mass extinction at the end of the Permian, around 252 million years ago, as some therocephalians managed to survive the disaster in pockets of prehistoric Africa, Europe, Asia, and Antarctica.

How and when did these ancient cousins of ours expand to inhabit so much of the Permian world? The fossil record has kept the answer a secret, but, paleontologists Adam Huttenlocker and Christian Sidor report, a new protomammal from Zambia helps flesh out the story.

They named the little creature Mupashi migrator. The protomammal wasn’t very big – you could have held it’s arrow-shaped skull in the palm of your hand – but it’s not the size that matters most. The closest known relatives of Mupashi, the paleontologists found, were species that lived in prehistoric Russia, far, far away from ancient Zambia. It’s a long-distance connection that hints at pathways, perhaps along the prehistoric coastlines, that let therocephalians disperse to different landmasses, and in time many of these animals split off into new forms. This was not preventative planning – the protomammals couldn’t have known what was coming – but they way they shuffled around the world gave them an edge when their world came crashing down.

The skull of Mupashi from above. From Huttenlocker and Sidor, 2016.
The skull of Mupashi from above. From Huttenlocker and Sidor, 2016.

Fossil Facts

Name: Mupashi migrator

Meaning: Mupashi is the Bemba word for spirit or ancestor, while migrator is a reference to the wide geographic range that the protomammal’s family occupied during the Permian.

Age: Between 259 and 254 million years ago.

Where in the world?: Northern Zambia.

What sort of critter?: A protomammal belonging to a group called karenitids.

Size: The skull is a little more than three inches long.

How much of the creature’s body is known?: A nearly-complete skull with several articulated neck vertebrae.

Reference:

Huttenlocker, A., Sidor, C. 2016. The first karenitid (Therapsida, Therocephalia) from the upper Permian of Gondwana and the biogeography of Permo-Triassic therocephalians. Journal of Vertebrate Paleontology. doi: 10.1080/02724634.2016.1111897

Previous Paleo Profiles:

The Unfortunate Dragon
The Cross Lizard
The South China Lizard
Zhenyuan Sun’s dragon
The Fascinating Scrap
The Sloth Claw
The Hefty Kangaroo
Mathison’s Fox
Scar Face
The Rain-Maker Lizard
“Lightning Claw”
The Ancient Agama
The Hell-Hound
The Cutting Shears of Kimbeto Wash
The False Moose
“Miss Piggy” the Prehistoric Turtle
Mexico’s “Bird Mimic”
The Greatest Auk
Catalonia’s Little Ape
Pakistan’s Butterfly-Faced Beast
The Head of the Devil
Spain’s Megatoothed Croc
The Smoke Hill Bird
The Vereda Hilarco Beast
The North’s Sailback
Amidala’s Strange Horn
The Northern Mantis Shrimp
Spain’s High-Spined Herbviore
Wucaiwan’s Ornamented Horned Face
Alcide d’Orbigny’s Dawn Beast
The Shield Fortress
The Dragon Thief
The Purgatoire River’s Whale Fish
Russia’s Curved Blade
The Dawn Mole
The Oldest Chameleon

A Blog by

Butterflies Behaving Badly: What They Don’t Want You to Know

Small Grass Yellow butterflies feed on fresh elephant dung in Kenya's Tsavo West National Park.
Small grass yellow butterflies feed on fresh elephant dung in Kenya’s Tsavo West National Park.
Photograph by Nigel Pavitt, Getty

Butterflies have had us fooled for centuries. They bobble around our gardens, all flappy and floppy, looking so pretty with their shimmering colors. We even write odes to them:

Thou spark of life that wavest wings of gold,
Thou songless wanderer mid the songful birds,
With Nature’s secrets in thy tints unrolled
Through gorgeous cipher, past the reach of words,
Yet dear to every child
In glad pursuit beguiled,
Living his unspoiled days mid flowers and flocks and herds!
Ode To A Butterfly, by Thomas Wentworth Higginson

But butterflies have a dark side. For one thing, those gorgeous colors: They’re often a warning. And that’s just the beginning. All this time, butterflies been living secret lives that most of us never notice.

Take this zebra longwing, Heliconius charithonia. It looks innocent enough. 

The zebra longwing butterfly was made Florida's state butterfly in 1996.
The zebra longwing butterfly was made Florida’s state butterfly in 1996.
Pixabay, CC0

But it’s also famously poisonous, and its caterpillars are cannibals that eat their siblings. And that’s hardly shocking compared with its propensity for something called pupal rape.

Once you know that a pupa is the butterfly in its chrysalis—in between being a larva and an adult—then pupal rape is pretty much what it sounds like. As a female gets ready to emerge from her chrysalis, a gang of males swarms around her, jostling and flapping wings to push each other aside. The winner of this tussle mates with the female, but he’s often so eager to do so that he uses his sharp claspers to rip into the chrysalis and mate with her before she even emerges.

Since the female is trapped in the chrysalis and has no choice in the matter, the term pupal rape came about, though some biologists refer to it more charitably as “forced copulation” or simply pupal mating. Whatever you call it, it’s hardly the stuff of children’s books.

The zebra longwing is certainly pretty, though. Maybe that’s how it got to be Florida’s state butterfly.

And don’t think for a minute that zebra longwings are an anomaly—plenty of their kin are bad boys, too.

One day in Kenya’s North Nandi forest, Dino Martins, an entomologist, watched a spectacular battle between two white-barred Charaxes. A fallen log was oozing fermenting sap, and while a fluffy pile of butterflies was sipping and slowly getting drunk, the two white-barred butterflies showed up and started a bar fight. Spiraling and slicing at one another with serrated wings, the fight ended with the loser’s shredded wings fluttering gently to the forest floor.

A green-veined Charaxes dines on animal poop.
Photograph by Dino Martins

Martins, a former National Geographic Emerging Explorer, wrote about Charaxes, or emperor butterflies, in Swara magazine, published in East Africa where he is now Director of Kenya’s Mpala Research Centre.

“They are fast and powerful,” he writes. “And their tastes run to stronger stuff than nectar: fermenting sap, fresh dung and rotting carrion are all particular favourites.”

That’s right; don’t get between a butterfly and a freshly dropped pile of dung. It drives them wild. They uncoil their probosces and slurp away, lapping up the salts and amino acids they can’t get from plants.

It’s called mud-puddling, and it’s very common butterfly behavior. It doesn’t have to be dung, although that’s always nice; you may see flocks of butterflies having a nip of a dead animal (as depicted in this diorama of butterflies eating a piranha), drinking sweat or tears, or just enjoying a plain old mud puddle.

(VIDEO: Did You Know Butterflies Drink Turtle Tears? Watch to find out why.)

But still, butterflies are harmless, right?

Sorry, kids—not always. Butterflies start life as caterpillars, which are far from harmless if you’re a tasty plant, and can be carnivorous. Some are even parasites: Maculinea rebeli butterflies trick ants into raising their young. The caterpillars make sounds that mimic queen ants, which pick them up and carry them into their colonies like the well-to-do being toted in sedan chairs. Inside, they are literally treated as royalty, with worker ants regurgitating meals to them and nurse ants occasionally sacrificing ant babies to feed them when food is scarce. Butterflies invented the ultimate babysitting con.

So, let’s review. Here are seven not-so-nice things butterflies are into:

  • Getting drunk
  • Fighting
  • Eating meat
  • Eating poop
  • Drinking tears
  • Tricking ants
  • Raping pupae

Don’t get me wrong—I like butterflies. In fact, I like them more knowing that they have a dark side. They’re far more interesting, more weird, than any ode to pretty colors could convey.

Happy Learn About Butterflies Day!

 

Reference:
Dino Martins. Flitting Emperors – and Forest Queens. SWARA Vol. 27 No. 2 / April–June 2004; pp. 52-55. No link available.

Dino Martins. ‘Mud-Puddle’ — or Be Damned. SWARA January—March 2006; pp. 66-68.

Queen Ants Make Distinctive Sounds That Are Mimicked by a Butterfly Social Parasite. Science: Vol. 323, Issue 5915, pp. 782-785. 2009.