Tag: Biology

According To Scientists, Winged Archaeopteryx Dinosaur Flew In Short Bursts Like A Pheasant

Archaeopteryx flapped its wings but was not capable of long distance flight. Nor could it soar like birds of prey.

Instead, the feathered Jurassic creature probably made short bursts of ­limited low-level flight to escape danger, say experts in Grenoble, France, after X-ray analysis of fossil bones.

Pheasants fly in a similar way to avoid predators or human hunters.

Archaeopteryx – which means “ancient wing” – lived in the Late Jurassic period in what is now southern Germany.

The first fossil skeleton of one of the creatures, known as the London Specimen, was unearthed in 1861 near Langenaltheim and is housed at London’s Natural History Museum.

Similar in size to a magpie, it shared characteristics of Earth-bound dinosaurs and modern birds, including winged feathers, sharp teeth, three fingers with claws, and a long bony tail.

However despite being thought of as the first bird, experts now view Archeopteryx as a flying dinosaur.

Nor was it a direct ancestor of modern birds. Despite sharing a common dinosaur ancestor with birds, Archaeopteryx represents a “dead end” side branch on the evolutionary tree.

Present day birds are generally believed to have evolved from a group of small meat-eating dinosaurs known as maniraptoran theropods.

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See The Amazing Way A Beetle Survives After Being Eaten

The toad’s reaction to the explosion deep in its stomach is not instantaneous. But in time the body shakes, the mouth opens, and the culprit is expelled: a mucus-covered beetle that will live to fight another day.

Japanese scientists captured footage of the great escape during lab tests that pitted the walking powder kegs that are bombardier beetles against hungry toads of different species and sizes.

So effective were the beetle’s defences against being eaten alive that even the researchers were taken aback.

The escape behaviour surprised us,” said Shinji Sugiura, an agricultural scientist who performed the studies with Takuya Sato at Kobe University.

An explosion was audible inside several toads just after they swallowed the beetles.”

From a chemical standpoint, bombardier beetles are among the most unstable animals on the planet.

When threatened, they mix chemicals in their hindquarters, hydrogen peroxide and hydroquinones, to produce an explosion of searing benzoquinone irritant.

The boiling spray repels most predators the beetles encounter.

Sugiura and Sato wanted to know if the bombardier’s defences might help them survive being swallowed by the toads they encountered in the forests of central Japan.

To find out, they collected beetles, Japanese common toads, and Japanese stream toads, and filmed what happened when predator met prey.

The footage captured heroic feats of survival. The toads caught the bombardier beetles with lightning fast flicks of the tongue. But once ingested, the beetles detonated their toxic bombs.

At times, Sugiura said, the explosions made an audible “bu” sound inside the amphibians. Vomiting ensued.

The defence was not always effective though. Only 34.8% of common toads and 57.1% of stream toads vomited up the beetles, which all survived their encounter with the predator’s stomach juices.

The odds of survival favoured large beetles being gobbled by small toads, probably because the bigger beetles unleashed more devastating toxic explosions.

While some beetles were thrown up within 15 minutes, others remained in the toads’ stomachs for nearly two hours, the equivalent of a Jonah-esque three-day ordeal in human terms.

To check that the explosions were key to survival, the scientists disarmed a batch of beetles by triggering their sprays until the chemicals ran out, and then left them alone with toads.

Only 5% of those eaten were vomited up, according to a report in Biology Letters.

How some bombardiers lived for so long in the toads’ stomachs remains a mystery.

In tests, Sugiura found bombardier beetles had a better chance than other ground beetles of surviving for 20 minutes inside toads’ stomachs, perhaps because they are better protected against stomach acid.

The bombardier beetle species may have evolved a high tolerance for toads’ digestive juices,” he said.

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Shy Pangolins Need World Spotlight To Survive

Reclusive, gentle and quick to roll up into a ball, pangolins keep a low profile.

But they are also the world’s most heavily trafficked mammal, and experts at the Convention on International Trade in Endangered Species (CITES) conference this week are ringing alarm bells over their survival.

Demand for pangolin meat and body parts has fueled a bloodbath, and driven the scale-covered, ant-eating mammal towards extinction.

More than a million pangolins are believed to have been poached from the wild in the past decade.

Most are used to supply demand in China and Vietnam, where they are highly regarded as a delicacy and an ingredient in traditional medicine.

At the CITES meeting in Johannesburg, conservationists will discuss moving pangolins into the highest protection category, which bans all international trade.

The pangolin today is regarded as the most heavily trafficked mammal in the world,” CITES chief John Scanlon told AFP.

“There has been a massive surge in the illegal take of the pangolin for its meat and for its scales.”

Currently CITES allows for trade in pangolins but under strict conditions.

Existing laws are clearly failing to protect pangolins from the poachers. A complete international trade ban is needed now,” said Heather Sohl, WWF-UK’s wildlife advisor.

There are four species of pangolin in Africa and four in Asia. Watchdogs say those in Asia are being eaten to extinction, while populations in Africa are declining fast.

Research published in the early 2000s estimated populations in China to have declined by up to 94 percent, said Dan Challender, pangolin expert at the International Union for Conservation of Nature.

Pangolins are covered in overlapping scales, and have pink, sticky tongues almost as long as their bodies.

When physically threatened, they curl into ball, making it easy for them to be picked up by hunters and put into a sack. About the size of a small dog, they are solitary, mostly nocturnal and cannot be farmed.

“Pangolins are notoriously difficult to keep in captivity — they only feed on wild ants and termites, and they are extremely prone to stress and dehydration, so they die,” Ray Jansen, of the African Pangolin Working Group, told AFP.

In Chinese traditional medicine, pangolin scales are ground into a powder believed to cure conditions from headaches and menstrual cramps to nose bleeding and lack of virility.

The scales are sometimes even used as guitar plectrums. In traditional African culture, some people believe in keeping a scale in their pockets to ward off evil.

Zimbabweans used to present the mammals to President Robert Mugabe during his early years in office, but the practice has been discontinued.

In Shona and Zulu culture, a pangolin is regarded as the greatest gift you can bestow on a chief, statesman or an elder,” said Jansen.

Pangolin fat, blood and bones are also highly valued in African traditional medicine.

According to Jansen, in South Africa a pangolin can sell for anything between 10,000 rand ($730) to 80,000 rand ($5,800) depending on the client.

India, the Philippines, Vietnam, Nigeria, Senegal and the United States are co-sponsoring the proposal to impose a total ban on pangolin trade.

The CITES treaty, signed by 182 countries and the European Union, protects about 5,600 animal and 30,000 plant species from over-exploitation through commercial trade.

The 12-day conference started Saturday and will sift through 62 proposals to tighten or loosen trade restrictions on some 500 species.

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This Shark Eats Grass, And No One Knows Why

These sharks might be taking the expression “eating like a horse” a bit too literally.

Scientists have discovered that some sharks are eating a large amount of seagrass, as a significant part of their diet—but experts aren’t sure why the fish are deviating from their traditional carnivorous diet.

New research has shown that seagrass can make up more than 50 percent of a bonnethead shark’s diet. The small, shovel-headed sharks are closely related to the more familiar hammerheads.

It’s still possible that the sharks are just incidentally munching on seagrass as they feed on other prey, said Samantha Leigh, a Ph.D. candidate at the University of California, Irvine and a National Geographic explorer.

Even if it is incidental, it is a very large amount of grass, so they have to be able to process that somehow,” said Leigh.

Leigh conducted a nutrient content analysis that showed bonnetheads were digesting 56 percent of the organic matter in seagrass, similar to young sea turtles.

But in order to be considered true omnivores, an animal must obtain nutritional value or energy from the plants they eat.

Without knowing why bonnetheads are eating seagrass, it’s hard to know if this habit is purposeful, said Leigh, who is studying the shark’s digestive behavior.

It’s very likely they have some sort of microbiome living in their gut that is producing some of the enzymes that they need to break down this plant material, which is something we commonly find in omnivorous and especially herbivorous species,” she said.

However, younger bonnethead sharks have been found to have more seagrass in their stomachs than adult bonnetheads, which could point to a learning curve as the sharks mature and understand how to feed without simultaneously eating seagrass, said Dana Bethea, a research ecologist with NOAA Fisheries in Florida.

There’s a lot of prey handling learning that goes on in the younger life stages until they get to be bigger and really get their mouths around what they’re feeding,” she said.

Leigh thinks it’s a “definite possibility” that this could be related to their unique diet, though Bethea isn’t sure.

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World’s Heaviest Bony Fish Identified And Correctly Named

Last December 6 in Tokyo, the world’s heaviest bony fish ever caught – weighing a whopping 2,300 kilogrammes – has been identified and correctly named by Japanese experts.

The fish is a Mola alexandrini bump-head sunfish, and not a member of the more commonly known Mola mola ocean sunfish species as originally thought, according to researchers from Hiroshima University.

Bony fish have skeletons made of bone rather than cartilage, as is the case for sharks or rays.

In the study, published in the journal Ichthyological Research, researchers led by Etsuro Sawai referred to more than one thousand documents and specimens from around the world – some of which date back 500 years.

Their aim was to clarify the scientific names for the species of the genus Mola in fish.

They also solved a case of mistaken identity. The Guinness World Records lists the world’s heaviest bony fish as Mola mola, researchers said.

However, Sawai’s team found a female Mola alexandrini specimen of 2,300 kilogramme and 2.72 meter caught off the Japanese coast in 1996 as the heaviest bony fish ever recorded.

Sawai’s team re-identified it as actually being a Mola alexandrini based on its characteristic head bump, chin bump and rounded clavus although this specimen was identified Mola mola until now.

Ocean sunfishes count among the world’s largest bony fish, and have for centuries attracted interest from seafarers because of their impressive size and shape, researchers said.

Specimens can measure up to three meters (total length), and many weighing more than two thousand kilogrammes have been caught.

Instead of a caudal fin, sunfish have a broad rudder-like lobe called a clavus, they said.

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Which Came First, The Lizard Or The Egg?

Evolution has been caught in the act, according to scientists who are decoding how a species of Australian lizard is abandoning egg-laying in favor of live birth.

Along the warm coastal lowlands of New South Wales, the yellow-bellied three-toed skink lays eggs to reproduce.

But individuals of the same species living in the state’s higher, colder mountains are almost all giving birth to live young.

Only two other modern reptiles—another skink species and a European lizard—use both types of reproduction.

Evolutionary records shows that nearly a hundred reptile lineages have independently made the transition from egg-laying to live birth in the past, and today about 20 percent of all living snakes and lizards give birth to live young only.

But modern reptiles that have live young provide only a single snapshot on a long evolutionary time line, said study co-author James Stewart, a biologist at East Tennessee State University.

The dual behavior of the yellow-bellied three-toed skink therefore offers scientists a rare opportunity.

One of the mysteries of how reptiles switch from eggs to live babies is how the young get their nourishment before birth.

In mammals a highly specialized placenta connects the fetus to the uterus wall, allowing the baby to take up oxygen and nutrients from the mother’s blood and pass back waste.

In egg-laying species, the embryo gets nourishment from the yolk, but calcium absorbed from the porous shell is also an important nutrient source.

Some fish and reptiles, meanwhile, use a mix of both birthing styles. The mother forms eggs, but then retains them inside her body until the very last stages of embryonic development.

The shells of these eggs thin dramatically so that the embryos can breathe, until live babies are born covered with only thin membranes—all that remains of the shells.

This adaptation presents a potential nourishment problem: A thinner shell has less calcium, which could cause deficiencies for the young reptiles.

Stewart and colleagues, who have studied skinks for years, decided to look for clues to the nutrient problem in the structure and chemistry of the yellow-bellied three-toed skink’s uterus.

Both birthing styles come with evolutionary tradeoffs: Eggs are more vulnerable to external threats, such as extreme weather and predators, but internal fetuses can be more taxing for the mother.

For the skinks, moms in balmier climates may opt to conserve their own bodies’ resources by depositing eggs on the ground for the final week or so of development.

Moms in harsh mountain climates, by contrast, might find that it’s more efficient to protect their young by keeping them longer inside their bodies.

In general, the results suggest the move from egg-laying to live birth in reptiles is fairly common—at least in historic terms—because it’s relatively easy to make the switch, Stewart said.

We tend to think of this as a very complex transition,” he said, “but it’s looking like it might be much simpler in some cases than we thought.

The skink-evolution research was published online August 16 by the Journal of Morphology.

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Narwhals Wearing Heart Monitors Reveal Danger Of Human Encounters

Normally when an animal is scared, it either remains very still and slows its heart rate and metabolism in hope that danger will pass like a possum playing dead, in an extreme case or the body revs up to power a “fight or flight” response.

But when narwhals get caught in fishing nets, surprisingly, they do both. Even as the narwhals pump their fins and tails as fast as they can to escape, their heart rates plummet to just three to four beats per minute.

Scientists report Thursday in the journal Science. For reference, that’s about as many beats per minute as a ground squirrel while it’s hibernating.

It’s the first time anyone has measured heart rate and performance at the same time for a diving cetacean, the group that includes whales, dolphins, and narwhals, says Terrie Williams, a wildlife ecophysiologist at the University of California, Santa Cruz and lead author of the new study.

The narwhals’ super-slow heartbeats were a surprise because animals need to pump enough blood around the body to supply oxygen to the brain and stay warm, Williams says.

What’s more, the lack of blood flow could prevent the narwhals’ bodies from removing nitrogen, which leads to decompression sickness, also known as the bends.

Narwhals have always been a bit of a mystery. It’s thought that there may be as many as 173,000 narwhals on Earth, but because of the animal’s remote habitat and cryptic nature, no one is really sure.

For starters, the animals live entirely above the Arctic Circle and tend to hang out in places where sea ice is so thick that it’s nearly impenetrable to ships.

They spend much of the day diving to depths of 4,500 feet or more where they hunt for halibut, cod, shrimp, and squid.

No one has ever seen a narwhal eat, by the way. Scientists know about their menu only from studying the gut contents of narwhals killed by local hunters.

In fact, the current study probably wouldn’t exist without indigenous hunters, since Williams and her coauthors relied on cooperation from the people of Ittoqqortoormiit, Greenland, to get access to the narwhals caught in their nets.

The local people would have normally harvested these animals, but instead agreed to let the narwhals go so they could be studied.

Before each animal was released, the scientists used suction cups to attach heart rate monitors and motion sensors called accelerometers to the entangled narwhals.

Williams suspects that other deep-diving cetacean species may also use this bizarre escape response when they become stranded.

If these animals also experience a cardiac freeze either as the result of noise pollution, entanglements, or other human impacts then perhaps the animals’ brains aren’t getting enough oxygen.

This might explain why some whales strand themselves again even after rescuers help them back into the waves.

I don’t have the proof,” says Williams, who published a paper earlier this year that showed noise pollution increases the amount of energy beaked whales expend on their dives.

But we are certainly seeking the proof.”

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Can Eating Too Much Make Your Stomach Burst?

I ate so much I’m about to burst!

Someone at your Thanksgiving table likely said this, after you’ve all stuffed your faces with turkey, mashed potatoes, sweet potatoes and the rest.

But how much would you have to eat in order for your stomach to actually burst? Is that even possible?

Interestingly enough, you can rupture your stomach if you eat too much,” says Dr. Rachel Vreeman, co-author of “Don’t Cross Your Eyes … They’ll Get Stuck That Way!” and assistant professor of pediatrics at Indiana University School of Medicine.

It is possible, but it’s very, very rare.

A handful of reports over the years document the tales of people who literally ate themselves to death, or at least came dangerously close.

Japanese doctors wrote in a 2003 case report that they believed it was a 49-year-old man’s “excessive over-eating” that caused his stomach to rupture, killing him.

And this 1991 case report describes a similar “spontaneous rupture” in an adult’s stomach “after overindulgence in food and drink.

Normally, your stomach can hold about one or one-and-a-half liters, Vreeman says — this is the point you may reach if you overdo it tomorrow, when you feel full to the point of nausea.

Pathologists’ reports seem to suggest the stomach is able to do OK handling up to about three liters, but most cases of rupture seem to occur when a person has attempted to stuff their stomach with about five liters of food or fluid.

It takes a certain amount of misguided determination to manage to override your natural gag reflex and continue to eat.

Which is, not surprisingly, reports of ruptured stomachs caused by overeating are most common in people with some sort of disordered eating, or limited mental capacity, Vreeman says.

Speaking of strong stomachs, you’d best have one in order to read this next paragraph. If vomiting isn’t happening, all that food and fluid still has to go somewhere.

The increasing volume of stuff in the gut puts pressure on the stomach’s walls, so much so that the tissue weakens and tears, sending the stomach contents into the body and causing infection and pain, Vreeman says.

Surgical intervention is necessary to repair a ruptured stomach and save the patient’s life.

In particular, she says, anorexics or bulimics may be at risk. In fact, Cedars-Sinai, the non-profit hospital in Los Angeles, actually lists this as a “symptom” of bulimia.

In rare cases, a person may eat so much during a binge that the stomach bursts or the esophagus tears. This can be life-threatening.

Other reported cases of spontaneous stomach rupture happen in individuals with Prader-Willi syndrome, a congenital disease that is characterized by, among other things, a kind of disordered eating.

An “intense craving for food,” resulting in “uncontrollable weight gain and morbid obesity.” according to the National Institutes of Health.

In a 2007 study examining the deaths of 152 individuals with the condition, 3 percent of those deaths were the result of gastric rupture and necrosis.

The takeaway here: This really happens, sometimes! Also: This is probably not going to happen to you.

Even if you’re starting to feel a bit sick or tired and overwhelmed from eating so much at Thanksgiving, you’re still far, far away from the scenario where you’re going to make your stomach actually explode,” Vreeman assures.

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5 Hard-Shelled Facts About Horseshoe Crabs

The plodding sea creatures have weird blood, weirder swimming habits, and a secret weapon that’s probably saved your life.


Discovered in 2008, the 25 millimeter-wide Lunataspis aurora crawled over Manitoba 445 million years ago. This makes it the world’s oldest-known horseshoe crab.

Four species are with us today, all of which closely resemble their long-extinct ancestors.

Supposedly frozen in time, horseshoe crabs are often hailed as “living fossils” by the media.

Yet, appearances can be misleading. Evolution didn’t really leave these invertebrates behind. They’ve transformed quite a bit over the past half-billion years.

For instance, some prehistoric species had limbs that split out into two branches, but today’s specimens have only one.


In fact, they aren’t even crustaceans. Unlike real crabs and their kin, horseshoe “crabs” lack antennae.

So, where do the strange ocean-dwellers belong on the arthropod family tree? Biologists classify them as chelicerates, a subphylum that also includes arachnids.

Members possess two main body segments and a pair of unique, pincer-like feeding appendages called chelicerae.


Large compound eyes rest on the sides of their shells. Come mating season, these bean-shaped units help amorous crabs locate a partner. Behind each one, there’s a small, primitive photoreceptor called a lateral eye.

Towards the front of the shell are two tiny median eyes and a single endoparietal eye. On its underside, a horseshoe has two “ventral eyes,” which presumably help it navigate while swimming.


Walking around on the ocean floor is generally how horseshoe crabs get from point A to point B.

Nevertheless, young ones will often flip over and start propelling themselves through the water, using their gills as extra paddles. With age, they do this less frequently.


Stinging isn’t one of them, despite what many falsely believe. Among its uses are assuming rudder duties and helping the arthropod right itself after getting stuck on its back.

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Over 200 Pterosaur Eggs And Embryos Has Been Found At A Site In China

An ancient site containing more than 200 fossilised eggs belonging to ancient flying reptiles known as pterosaurs has been found.

The eggs belong to a species called Hamipterus tianshanensis, which soared over what is now north west China about 120 million years ago.

The palaeontologists who made the discovery note both the “extraordinary quantity of eggs”, and the fact some of them contain “the first pterosaur three-dimensional embryos”.

This level of preservation allows researchers to learn more about the behaviour of these prehistoric creatures.

Previous evidence of pterosaur reproduction has been rather lacking, limited to a handful of eggs from Argentina and China identified in 2004.

Prior to this, there was no evidence at all these reptiles laid eggs.

But the new discovery, which consists not only of eggs but the bones of adults as well, paints a vivid picture of a nesting colony.

The findings were published in a paper led by Dr Xiaolin Wang of the Chinese Academy of Sciences in the journal Science.

Dr Wang and his collaborators outline how they used CT scans to look inside the eggs, 16 of which contained embryos that were somewhat intact.

From these embryos, the scientists could see that the structures supporting the pectoral muscles – crucial for flight – were noticeably underdeveloped.

This allowed the scientists to infer that when these animals hatched, they were unable to fly. The newly hatched pterosaurs would therefore have required care and attention from their parents if they were to survive.

The fossils also reveal more secrets about pterosaur lifestyles.

“The find reinforces the view that pterosaur eggs were soft-shelled and needed to be buried,” said Dr Charles Deeming, a biologist at the University of Lincoln who was not involved in the study.

This draws comparison with modern day lizard eggs, and suggests that while the pterosaurs may have cared for their offspring, they didn’t incubate them like birds. Instead, they relied on the earth to keep their eggs warm.

The rarity of such a fossilisation event makes this discovery, and the knowledge gained from it, all the more precious.

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