Tag Archives: reptile

Saltwater Crocodiles: the world’s oldest and largest reptile

From the east of India, all through to the north of Australia, one fearsome, cold-blooded predator stalks the coasts. This hypercarnivore will contend with any that enters its watery domain, from birds to men to sharks, and almost always win that fight. Fossil evidence shows that this species has been plying its bloody trade for almost 5 million years, remaining virtually unchanged, a testament to just how efficient a killing machine it is. Looking it in the eye is the closest thing we have to staring down a carnivorous dinosaur.

Saltwater crocodile at the Australia Zoo, Beerwah, South Queensland. Image credits Bernard Dupont / Flickr.

This animal is the saltwater crocodile (Crocodylus porosus). It has the distinction of being the single largest reptile alive on the planet today, and one of the oldest species to still walk the Earth.

Predatory legacy

The earliest fossil evidence we have of this species dates back to the Pliocene Epoch, which spanned from 5.3 million to 2.6 million years ago.

But the crocodile family is much older. They draw their roots in the Mesozoic Era, some 250 million years ago, when they branched off of archosaurs (the common ancestor they share with modern birds). During those early days, they lived alongside dinosaurs.

Crocodiles began truly coming into their own some 55 million years ago, evolving into their own species in the shape we know them today. They have remained almost unchanged since, a testament to how well-adapted they are to their environments, and the sheer efficiency with which they hunt.

This makes the crocodile family, and the saltwater crocodile as one of its members, one of the oldest lineages alive on the planet today.

The saltwater crocodile

With adult males reaching up to 6 or 7 meters (around 20 to 23 ft) in length, this species is the largest reptile alive today. Females are smaller than males, generally not exceeding 3 meters in length (10 ft); 2.5 meters is considered large for these ladies.

Image credits fvanrenterghem / Flickr.

The saltwater crocodile will grow up to its maximum size and then start increasing in bulk. The weight of these animals generally increases cubically (by a power of 3) as they age; an individual at 6 m long will weigh over twice as much as one at 5 m. All in all, they tend to be noticeably broader and more heavy-set than other crocodiles.

That being said, they are quite small as juveniles. Freshly-hatched crocs measure about 28 cm (11 in) in length and weigh an average of only 71 g — less than an average bag of chips.

Saltwater crocodiles have large heads, with a surprisingly wide snout compared to other species of croc. Their snout is usually twice as long overall as they are wide at the base. A pair of ridges adorn the animal’s eyes, running down the middle of their snout to the nose. Between 64 and 68 teeth line their powerful jaws.

Like their relatives, saltwater crocodiles are covered in scales. These are oval in shape. They tend to be smaller than the scales of other crocodiles and the species has small or completely absent scutes (larger, bony plates that reinforce certain areas of the animal’s armored cover) on their necks, which can serve as a quick identifier for the species.

Young individuals are pale yellow, which changes with age. Adults are a darker yellow with tan and gray spots and a white or yellow belly. Adults also have stripes on the lower sides of their bodies and dark bands on their tails.

That being said, several color variations are known to exist in the wild; some adults can maintain a pale coloration throughout their lives, while others can develop quite dark coats, almost black.

Behavior, feeding, mating

Saltwater crocodiles are ambush predators. They lie in wait just below the waterline, with only their raised brows and nostrils poking above the water. These reptiles capture unsuspecting prey from the shore as they come to drink, but are not shy to more actively hunt prey in the water, either. Their infamous ‘death roll’ — where they bite and then twist their unfortunate victim — is devastating, as is their habit of pulling animals into the water where they drown. But even their bite alone is terrifying. According to an analysis by Florida State University paleobiologist Gregory M. Erickson, saltwater crocodiles have the strongest bite of all their relatives, clocking in at 3,700 pounds per square inch (psi).

That’s a mighty bitey. Image credits Sankara Subramanian / Flickr.

Apart from being the largest, the saltwater crocodile is also considered one of the most intelligent reptiles, showing sophisticated behavior. They have a relatively wide repertoire of sounds with which they communicate. They produce bark-like sounds in four known types of calls. The first, which is only performed by newborns, is a short, high-toned hatching call. Another is their distress call, typically only seen in juveniles, which is a series of short, high-pitched barks. The species also has a threat call — a hissing or coughing sound made toward an intruder — and a courtship call, which is a long and low growl.

Saltwater crocodiles will spend most of their time thermoregulating to maintain an ideal body temperature. This involves basking in the sun or taking dips into the water to cool down. Breaks are taken only to hunt or protect their territory. And they are quite territorial. These crocodiles live in coastal waters, freshwater rivers, billabongs (an isolated pond left behind after a river changes course), and swamps. While they are generally shy and avoidant of people, especially on land, encroaching on their territory is one of the few things what will make a saltwater crocodile attack humans. They’re not shy to fight anything that tresspasses, however, including sharks, monkeys, and buffalo.

This territoriality is also evident in between crocs. Juveniles are raised in freshwater rivers but are quickly forced out by dominant males. Males who fail to establish a territory of their own are either killed or forced out to sea. They just aren’t social souls at all.

Females lay clutches of about 50 eggs (though there are records of a single female laying up to 90 in extraordinary cases). They will incubate them in nests of mud and plant fibers for around 3 months. Interestingly, ambient temperatures dictate the sex of the hatchlings. If temperatures are cool, around 30 degrees Celsius, all of them will be female. Higher sustained temperatures, around 34 degrees Celsius, will produce an all-male litter.

Only around 1% of all hatchlings survive into adulthood.

Conservation status

Saltwater crocodiles have precious few natural predators. Still, their skins have historically been highly prized, and they have suffered quite a lot from hunting, both legal and illegal. Their eggs and meat are also consumed as food.

In the past, this species has been threatened with extinction. Recent conservation efforts have allowed them to make an impressive comeback, but the species as a whole is much rarer than in the past. They are currently considered at low risk for extinction, but they are still of especial interest for poachers due to their valuable meat, eggs, and skins.


Saltwater crocodiles are an ancient and fearsome predator. They have evolved to dominate their ecosystems, and do so by quietly lurking just out of sight. But, like many apex predators before them, pressure from humans — both directly, in the form of hunting, and indirectly, through environmental destruction and climate change — has left the species reeling.

Conservation efforts for this species are to be applauded and supported. Even though these crocodiles have shown themselves willing to attack humans if we are not careful, we have to bear in mind that what they want is to be left alone and unbothered. It would be a pity for this species, which has been around for millions of years, which has come from ancient titans, survived for millennia and through global catastrophe, to perish.

World’s smallest reptile comfortably fits on your fingertip

Brookesia nana. Credit: Frank Glaw.

A tiny male chameleon from Madagascar has now been crowned the world’s smallest reptile. The wee creature measures only half an inch (13.5 millimeters) in length from the snout to its rear-end (not counting the tail), small enough for the chameleon to stay comfortably perched on a human fingertip, despite its disproportionately large genitals.

Evolution favors both the very big and the very small

The chameleon, known as Brookesia nana, was recently described by a team of researchers led by Frank Glaw, a German herpetologist working at the Zoologische Staatssammlung in München.

Glaw is no stranger to novel reptilians. In fact, he is one of the foremost authorities in Madagascarian fauna, having described over 200 species, several of which are named after him.

In 2012, Glaw described Brookesia micra, another tiny reptile native to the islet of Nosy Hara in Madagascar. Perhaps you remember a photo of it perched on the head of a match, which was widely circulated on social media. At the time, the 1.1-inch (29 millimeters) adorable-looking animal was deemed the smallest known chameleon — until now when B. micra made room for B. nana.

A juvenile Brookesia micra standing on the head of a match. Credit: Frank Glaw, Jörn Köhler, Ted M. Townsend, Miguel Vences.

Writing in the journal Scientific Reports, Glaw and colleagues reported on an “extreme miniaturization of a new amniote vertebrate.” Miniaturization refers to the evolutionary reduction of adult body size. Miniaturized taxa are frequently characterized by a trend towards reduction and simplification of various structures and organs.

In this case,B. nana has been miniaturized compared to a regular-sized chameleon, which can be 50 times larger, almost close to the minimum possible body size. Meanwhile, the world’s largest reptile, the saltwater crocodile, can weigh up to two tons.

However, B. nana isn’t exactly a scaled-down version of a typical chameleon. One of its defining features is its oversized sexual organs, two tubular genitals measuring roughly 18.5% of the animal’s total body size.

Close-up of B. nana‘s hemipenes (reproductive organs). Credit: Frank Glaw, Scientific Reports.

Such is the case for the male, which is surprisingly smaller than the female, the latter measuring 0.7 inches in length (19.2 millimeters). But perhaps this oddly reversed sexual dimorphism will not stand the test of time. The elusive tiny chameleon was described based on only two specimens, a sample size that is woefully small to draw any firm conclusions. What’s more certain is that this species, although just barely discovered, may be threatened by extinction judging by its limited range and challenges in identifying new specimens. 

Oldest feather does not belong to Archaeopteryx

The mystery of a 150-million-year-old feather has finally been solved — least partially: it didn’t belong to Archaeopteryx, but its owner remains elusive.

The isolated “Archaeopteryx” feather is the first fossil feather ever discovered. The top image shows the feather as it looks today under white light. The middle image, the original drawing from 1862 by Hermann von Meyer. Bottom image is Laser-Stimulated Fluorescence (LSF). Note how the quill is not visible today, but clearly visible in the original drawing. LSF imaging showing the halo of the missing quill. Scale bar is 1cm. Image Credits: The University of Hong Kong.

The discovery of the first Archaeopteryx fossil in 1860 was a pivotal moment for both biology and geology. It showed a transitional creature, a link between dinosaur and birds, confirming what many scientists were already starting to support: that birds evolved from lizards. This 150-million-year-old creature fits like a charm into these theories and is still crucial for our understanding of evolution.

But just before Archaeopteryx was discovered, a single, elusive, fossilized feather was uncovered. To this day, this is the oldest feather we’ve ever discovered. This feather was thought to belong to an Archaeopteryx and even used to name this creature — but it might not have belonged to Archaeopteryx at all.

Right from the start, there were some doubts. Initial descriptions of the fossil mention a rather long quill visible on the fossil, which would indicate that it is a primary feather. However, the quill is no longer visible today, and has not been for a long time. There have been several attempts to uncover the missing quill with imaging techniques, but none found anything. So was the quill still there?

Researchers have now used a novel imaging technique called Laser-Stimulated Fluorescence (LSF) to analyze the fossil. LSF revealed the missing quill (or rather, its remaining halo), settling the old mystery.

“It is amazing that this new technique allows us to resolve the 150-year-old mystery of the missing quill,” says Daniela Schwarz, co-author in the study and curator for the fossil reptiles and bird collection of the Museum für Naturkunde, Berlin.

But the method also dethroned an idol: it most certainly did not belong to Archaeopteryx the team says. LSF allowed an unprecedented view into the structure of the feather, revealing the lack of a distinct s-shaped centerline, a defining characteristic of covert feathers. The team also ruled out the possibility that it could be a primary, secondary, or tail feather.

A 2011 study found that Archaeopteryx was almost certainly black. This is an artistic reconstruction by Nobu Tamura, showing what the bird might have looked like.

So if it didn’t belong to Archaeopteryx, then who did it belong to?

Well, researchers aren’t really sure, but it was probably another feathered dinosaur. The fact that such a creature exists suggests that there was much more diversity in feathered dinosaurs than we originally thought. Archaeopteryx remains a key link in dinosaur-bird evolution, but maybe it wasn’t all that unique — and maybe several other creatures boasted similar features.

It’s remarkable how new techniques enable us to study ancient creatures. We will definitely be hearing more of LSF in the future, researchers conclude.

“The success of the LSF technique here is sure to lead to more discoveries and applications in other fields. But, you’ll have to wait and see what we find next!” added Tom Kaye, the study’s lead author.

Archaeopteryx lived in the late Jurassic, some 150 million years ago. It had more in common with dinosaurs than birds (jaws with sharp teeth, three fingers with claws, a long bony tail, hyperextensible second toes), but it still exhibits definite bird-like features, such as its broad, feathered wings.

The paper ‘Detection of lost calamus challenges identity of isolated Archaeopteryx feather’ by Kaye, M. Pittman, G. Mayr, D Schwarz and X. Xu, has been published in Scientific Reports.

 

A figure representing the 38 Kayentatherium babies found with an adult specimen. Credit: University of Texas.

Jurassic-era mammalian relative found with 38 of its babies’ skulls

Mammals today give birth to relatively few offspring with larger brains than other vertebrate species. However, this strategy wasn’t always popular. According to a new study performed at the University of Texas, a mammalian precursor no bigger than a small dog would give birth to as many as 38 babies at a time.

A figure representing the 38 Kayentatherium babies found with an adult specimen. Credit: University of Texas.

A figure representing the 38 Kayentatherium babies found with an adult specimen. Credit: University of Texas.

The 185-million-year-old creature in question, known as Kayentatherium wellesi, was a cynodont (“dog teeth”) — the closest reptile relatives of mammals

Cynodonts predate dinosaurs, first appearing in the fossil record about 260 million years ago, during the Permian period. Their descendants include marsupial and placental mammals (the ‘default‘ mammals), as well as monotremes — mammals that lay eggs instead of giving birth to live young, such as the platypus and echidna.

Despite their mammal-like skulls and jaws, cynodonts were still reptiles. K. wellesi is a prime example of just how different pre-mammalian animals could be from the lineage they spawned.

This particular fossil specimen — recently described by researchers at the University of Texas — was discovered 18 years ago in the Kayenta Formation of northeastern Arizona. In wasn’t until 2009 that Sebastian Egberts, at the time a fossil preparator at the University of Texas, recognized the excavated chunk of rock for its real worth. Protruding specks of tooth that looked like they belonged to some fish or primitive reptile later turned out to be something far more exciting.

The skull of a baby Kayentatherium, which is only about 1 centimeter long. Credit: Eva Hoffman / The University of Texas at Austin.

The skull of a baby Kayentatherium, which is only about 1 centimeter long. Credit: Eva Hoffman / The University of Texas at Austin.

Using micro-computed tomography (micro-CT) scans, researchers were able to resolve the fine features of the fossils encased in the slab without actually having to cut it open. Inside it, researchers found the fossils of a mother and the tiny jaws, teeth, skulls, and partial skeletons of its babies — no fewer than 38 individuals. The babies’ skulls were proportional to the mother’s, like miniature versions of adult K. wellesi. This is the first evidence of a mammal precursor’s babies on record.

The skulls of the cynodont’s babies are just 0.4 inches (1 cm) long, a tenth of the size of their mothers. However, modern mammal babies have disproportionately bulbous heads, that encase their big brains. Modern mammals also have much smaller litter sizes.

Credit: Eva Hoffman / The University of Texas at Austin.

Credit: Eva Hoffman / The University of Texas at Austin.

It makes sense to birth fewer offspring when switching strategies to big-brained babies — it’s simply far more energy intensive to bear and raise them. These findings suggest that a critical step in the evolution of mammals was trading big litters for big brains.

Kayentatherium is an extinct mammal relative that lived during the Early Jurassic. Credit: Eva Hoffman / The University of Texas at Austin.

“Just a few million years later, in mammals, they unquestionably had big brains, and they unquestionably had a small litter size,” study co-researcher Timothy Rowe, a professor of geoscience at the University of Texas, said in a statement.

K. wellesi’s impressive litter of 38 offspring likely developed inside eggs, akin to reptiles, or had just hatched when they perished.

Ultimately, following the development of mammalian reproduction relates to human development. This way, we can learn more about the evolutionary processes that shaped our species.

“These babies are from a really important point in the evolutionary tree,” study lead researcher Eva Hoffman, a graduate student of geosciences at the University of Texas, said in a statement. “They had a lot of features similar to modern mammals, features that are relevant in understanding mammalian evolution.”

The findings appeared in the journal Nature and were presented at the 78th annual Society of Vertebrate Paleontology meeting.

Why do snakes flick their tongues?

Despite popular belief, snake tongues have no receptors for taste or smell. However, they flick their tongues to collect chemicals from the air or ground, using the so-called Jacobson’s Organ in the top of the mouth.

Snakes are terribly odd creatures, with their cold-blooded no-legs approach to life, but they’ve been around for over 100 million years, so they must be doing something right. Among the distinctive features of these elongated, carnivorous reptiles is their forked twin tongue.

Folklore and old explanations

Since the dawn of mankind’s interaction with snakes, we’ve noticed their eerie forked tongues flicking in and out — but why do they do it? Aristotle was seemingly fascinated by snakes and wrote about them on several occasions. Somehow, he managed to be very wrong, and yet also very close to the real answer. He wrote that “nature does not do anything in vain” and does “what is best among the possibilities,” something which is somewhat consistent with the principles of evolution. About the tongue, he wrote that it provides snakes with “a twofold pleasure from savors, their gustatory sensation being as it were doubled.”

In the 17th century, the idea that snakes catch insects with their tongue was popularized, and even though this has never been observed to be the case, it was still widely believed. However, this is true for other reptiles — most notably chameleons.

The Italian astronomer Giovanni Hodierna thought snakes use their tongues to clean dirt from their nose, which is a more reasonable explanation, though equally unlikely.

Two myths have also been perpetuated about snake tongues. The first is that they use the tongue to cover the prey in saliva before swallowing it. However, even a superficial investigation will reveal that the delicate tongue is neither well-suited or capable of such an act. The other myth is that it is a stinger, or the source of the snake venom, something which again, was disproven by autopsies since the Renaissance. This latter belief was probably popularized by quotes in the Bible and in Shakespearean literature. It’s surprising that so many myths still surround this phenomenon, but it’s probably understandable since snakes themselves are surrounded by a great deal of myth and folklore.

Why snakes really flick their tongue

A thorough investigation of snake behavior will reveal that through the tongue, the snake gets some understanding of its surrounding. This was determined by the investigations of French naturalist Bernard Germain de Lacépède in the early 1800s. Various 19th-century scholars have believed the tongue to be an organ of smell, taste, or even vibrations. However, these theories were displaced by thorough experiments.

More recent studies have learned that a snake tongue picks up particles or odors from the air. The two tips of the tongue are then introduced into the corresponding pair of what is called Jacobson’s organ, where they evoke different signals which are then transmitted electrically to the brain.

Keep in mind that this is neither a sense of smell nor taste — the tongue does not have receptors for smell or taste. It simply picks up the chemicals from the air or ground and passes them to Jacobson’s Organ.

[panel style=”panel-info” title=”Jacobson’s Organ” footer=””]The organ (also called the Vomeronasal organ, or VNO) was actually discovered in the 18th century, but its purpose wasn’t properly understood at the time. The organ is mainly used to detect pheromones, chemical messengers that carry information between individuals of the same species. Snakes have very well developed Jacobson’s organ, which allows them to sense a wide variety of chemicals.

But snakes aren’t the only creatures to have this biological feature. Many mammals also have it, and it is typically involved in the so-called flehmen response — a behavior in which an animal curls back its upper lip exposing its front teeth, inhales with the nostrils usually closed and then often holds this position for several seconds. The flehmen response is often used by horses and cats. However, oscillating tongue flicks are unique to snakes.

In humans, the VNO remains an area of active research and a controversial subject. The presence of vomeronasal organ has been observed in fetuses, though several studies found that it regresses as the fetus develops. It’s unclear if the VNO continues into adult life, as some studies have found evidence of it, while others have not. Furthermore, even if it does exist, it’s not clear that it is active and functional — even though chemical communication has been proven to exist between humans.[/panel]

So, snakes flick their forked tongues to pick up chemicals from the air or from the ground, something which is akin to smelling but is really not the same as smell. But this doesn’t really tell the whole story.

Advanced features of the snake tongue

While this explains why snakes flick their tongue, we still haven’t discussed why their tongue is forked — and there’s a very good reason for it.

Because it is forked, it can collect information in two places at once. This allows the snakes to create a chemical gradient of sorts, which gives them a sense of direction. In other words, snakes use their forked tongues to navigate the chemical world in 3D. It’s the same principle with owls, who developed asymmetrical ears to collect sounds in 3D. This makes it much easier for snakes to pick up and follow trails left behind by other animals.

This theory was confirmed in the 1930s, in an age before the ethical use of animals in research was regulated. German biologist Herman Kahmann cut off the forked parts of a snake tongue. He found that while the snakes were still efficient at picking up chemicals, they were much less able to follow trails.

More ethical studies have shown that the snake is effective in following not only the trail of potential prey — but also that of mates. In the 1980s, snake biologist Neil Ford at the University of Texas at Tyler followed male garter snakes as they were chasing the trail of females. He found that if both tips of the male tongue fall within the trail left by the female, the snake continues his route. But if one side falls outside of it, the snake turned his head away from that side, accurately following the female trail. Snake ecologist Chuck Smith at Wofford College also found that male Copperheads have longer, more deeply-forked tongues than females, which seems to support this theory.

Also, it was once thought that since Jacobson’s organ is forked just like the tongue, the tongue delivers the chemicals directly to the organ, but X-ray videos have revealed that this is not the case. It seems that the tongue simply deposits the chemicals on the bottom of the mouth, and when the mouth closes, the bottom and the top of the mouth, where Jacobson’s organ is located, come into contact.

Recent studies have also sought to quantify snake tongue flicks by analyzing tongue flick behavior. Gheylen Daghfous and his colleagues from the Université de Montreal have found two different tongue flick behaviors: one when the snakes picked up chemicals from the air, and another one when they pick chemicals up from the ground. They explain this as a specialized behavior which optimizes how chemicals are picked up from different environments.

Odor dispersion and how it is picked up by different creatures is still an area that’s poorly understood. While we can now say we truly know why snakes flick their tongues, the intricacies of this process are still not fully understood, and future studies will no doubt reveal even more about the impressive creatures we call snakes.

Nile crocodiles. Credit: Pixabay.

Scientists play classical music to fancy crocodiles, then scan their brains

Nile crocodiles. Credit: Pixabay.

Nile crocodiles. Credit: Pixabay.

The lives of some scientists are anything but boring. In a world first, researchers placed a Nile crocodile inside an MRI machine and scanned its brain while it was listening to classical music. Bach was on the playlist, if you were just wondering about the reptile’s musical tastes.

The study might sound gimmicky but it’s actually very important. The results, for instance, suggest that the fundamental neuronal processing mechanisms for sensory stimuli evolved hundreds of millions of years ago and can be traced back to a common ancestor of all vertebrates.

Croc brain on music

Brains don’t fossilize, which is a bummer for scientists who would like to know how the most ancient brains function and trace back the evolutionary history of the ultimate biological hardware. Luckily, they have at their disposal the next best thing: crocs. You see, crocodiles have barely changed in the last 200 million years or so, and, as such, they represent the perfect animal model for investigations of ancient neural workings.

Researchers led by Felix Ströckens from the Department of Biopsychology at Ruhr University Bochum wanted to investigate how the crocodilian brain might respond to complex sounds, so that they might compare the patterns to those of birds and mammals. To this end, the researchers inserted a Nile crocodile (Crocodylus niloticus) into an MRI machine in order to scan its brain. Yes, science can be very exciting (and dangerous).

Magnetic resonance imaging, or MRI, uses a powerful magnetic field, radio waves and a computer to produce detailed pictures of the inside of your body. Previously, MRI scans have been performed on various mammals, but this is the first time a cold-blooded reptile was put inside an MRI machine, which had to be modified for this study.

Croc prepared for MRI scan. Credit: Felix Ströckens.

Croc prepared for MRI scan. Credit: Felix Ströckens.

As you might imagine, placing a croc inside a very cramped and noisy machine was challenging work. In order to make sure the croc didn’t move inside the machine for proper scanning, the reptile was sedated and had its snout taped for extra safety. The fact that the animal is cold-blooded added to the complexity of task since brain scans can be skewed by the animal’s body temperature. Luckily, the researchers were at least fortunate enough to work with very gentle crocs. Perhaps, the selection of sounds that the researchers played, which also included classical music, helped to calm the beasts.

“In the first step, we had to overcome a number of technical obstacles,” said research team member Mehdi Behroozi. “For example, we had to adjust the scanner to the crocodile’s physiology, which differs massively from that of mammals in several aspects.”

The five juvenile crocs used in the study were exposed to various visual and auditory stimuli like flashing red and green lights or random chord noises between 1,000 Hz and 3,000 Hz. To gauge the croc’s response to complex sounds, the researchers played Johann Sebastian Bach’s Brandenburg Concerto No. 4, which had been employed in previous studies that worked with other animals, thus providing a good reference.

The brain scans revealed that different brain areas were activated in the crocodilian brain when the animal was subjected to complex sounds compared to when basic sounds were played. The observed pattern is very similar to that seen in mammals and birds which were exposed to music. This suggests that the structural and functional machinery of this kind of sensory processing appeared hundreds of millions of years ago. This ability was then preserved and passed down the evolutionary family tree.

“It was technical breakthrough,” Ströckens told Gizmodo. “We could prove that fMRI can be used in reptiles which differ massively in their physiology from mammals or birds (e.g. body temperature and breathing patterns). This will allow future studies to investigate many species which have not been investigated yet with this non-invasive method.”

Researchers from Iran, South Africa, France and Germany participated in the study, which was published in the journal Proceedings of the Royal Society B: Biological Sciences.

Illustration of Captorhinus, a captorhinid reptile that lived during the Permian period, showing breakable tail vertebrae. Image credit: Robert Reisz.

Permian lizard detached tail to escape predators, a trait still found in modern lizards

An ancient lizard, which lived more than 250 million years ago, could detach its tail if it was bitten by a predator. This is the first creature that we know of that employed this escape strategy, employed today by modern lizard species such as skinks.

Illustration of Captorhinus, a captorhinid reptile that lived during the Permian period, showing breakable tail vertebrae. Image credit: Robert Reisz.

Illustration of Captorhinus, a captorhinid reptile that lived during the Permian period, showing breakable tail vertebrae. Image credit: Robert Reisz.

Researchers at the University of Toronto Mississauga closely studied an extinct group of lizards known as captorhinidae. These lizards, which ranged in size from very small to large, are recognizable by the generally triangular shape of their skull when viewed dorsally. They first appeared in the fossil record during the Late Carboniferous in North America, from where the reptiles spread all over the world. All captorhinids became extinct by the Permian.

As omnivores and herbivores, the reptiles would often find themselves preyed by carnivorous amphibians and early mammals while foraging for food. As such, these creatures had to find ways to adapt to a competitive lifestyle. When they weren’t agile enough to escape an encounter with a hungry predator that grabbed them by the tail, the ancient reptiles would escape by discarding it. Professor Robert Reisz and colleagues at the University of Toronto Mississauga learned this after they found captorhinids has breakable tail vertebrae.

The researchers examined more than 70 tail vertebrae from both juveniles and adults and found multiple cracks in the tail vertebrae which acted like the perforated lines between two sheets of paper towels. With the help of various paleontological techniques, the scientists determined that these cracks formed naturally as the vertebrae developed and weren’t the result of some injury. The cracks in adults tended to fuse up while those found in juveniles were easier to break, which makes sense since young reptiles are more vulnerable to predation.

“If a predator grabbed hold of one of these reptiles, the vertebra would break at the crack and the tail would drop off, allowing the captorhinid to escape relatively unharmed,” said Reisz, who is the senior author of the paper published in the journal Scientific Reports.

“Being the only reptiles with such an escape strategy may have been a key to their success, because they were the most common reptiles of their time, and by the end of the Permian period 251 million years ago, captorhinids had dispersed across the supercontinent Pangea,” he added.

This trait disappeared with the last captorhinid about 250 million years ago. It took lizards a lot of time before they re-evolved this feature 70 million years ago. Today, modern lizards like skinks still retain this ability.

 

10 of the Weirdest Prehistoric Creatures

Eons ago, many millennia before written history, bizarre animals roamed the Earth. The most renowned of these prehistoric creatures were the dinosaurs. Countless films have been made featuring these great reptiles. But during the various epochs of our world’s prehistory there existed many other weird and wonderful beasts. And many of them had names that were even weirder.

You will find some of these to be even more fascinating than dinosaurs. It was in this era before the dominance of mankind that life on Earth underwent a great deal of evolution. And, in fact, the Earth itself, its land masses and oceans, also evolved drastically.

Ichthyostega

Credit: Wikimedia Commons.

Credit: Wikimedia Commons.

Living in the late Devonian period, Ichthyostega was one of the earliest amphibian-like animals. It had the head and tail of a fish, and it needed to return to the water in order to breed. The feature which differentiated Ichthyostega from lobe-finned fish was the limbs. In Ichthyostega, the fins were jointed, with leg and toe bones. Ichthyostega‘s foot was odd by modern standards. It had eight toes.

Sharovipteryx

Sharovipteryx. Credit: Wikimedia Commons

Scientists believe Sharovipteryx to be an ancestral link to the winged reptiles the pterosaurs. Not classified as a true pterosaur itself, it lived in the early Triassic period over 240 million years ago. It’s in a class of its own. The creature’s remains have been unearthed at the Madygen Formation in Kyrgyzstan, Central Asia. It was a mere one foot in length. It had four appendages which seem to have possessed thin flaps of skin like wings. The two forelimbs were quite short, and the rear limbs were much longer. Some theorize this design enabled Sharovipteryx to jump with ease. Paleontologists believe its mode of transportation was more like gliding than true flying.

Longisquama

Longisquama. Credit: Wikimedia Commons.

Longisquama. Credit: Wikimedia Commons.

This creature was what has been called a diapsid. The diapsids were a reptilian subclass which eventually would evolve into the most important reptile subclass. But it began as a small group of climbing and gliding reptiles. The diapsids lived in forests located on the supercontinent Pangea during the Triassic period. Thus, Pangea was the place Longisquama would have called home.

The skeleton’s most stunning feature is a double row of long scale-like structures running along its back, forming six to eight pairs. It had one pair of scales for each of its pairs of ribs. The scales had a central hollow vein, like bird feathers. But unlike feathers, Longisquama‘s scales seem to have been formed of flat sheets and not genuine plumes. This is the creature featured in this article’s header image.

Stagonolepis

Illustration of an Aetosaur. Credit: Wikimedia Commons.

 

Stagonolepis was an aetosaur, sometimes also synonymically referred to as a stagonolepid. The Triassic world was filled with a vast variety of crocodilian species. The aetosaurs were unique among the early crocodiles since they were herbivorous. Unlike modern crocs, they were vegetarians. And Stagonolepis was one of the most prevalent of the stagonolepids at the close of the Triassic. Its long, narrow body was armor-coated, and it was capable of reaching a length of nine feet. Some artist renderings depict a creature which rather resembles a modern armadillo.

Casea

Credit: Wikimedia Commons.

Credit: Wikimedia Commons.

The caseids were another group of early reptiles. No reptile living today looked as odd as the Casea. The massive pig-like body, tiny head, overhanging upper jaw with peg-like teeth, and lower jaw with no teeth gave Casea a goofy look. These prehistoric creatures had large ribcages and were capable of reaching four feet long. Their prime occurred in the late Permian period. The term “casea” means “cheesy.”

Nothosaurus

Nothosaurus. Credit: Wikimedia Commons.

Nothosaurus. Credit: Wikimedia Commons.

Nothosaurs were related to the plesiosaurs but did not always have the best physical capabilities for coping with marine life. These reptiles did not have gills. So they had to come up to the surface for fresh air. Their long necks which would have easily been able to sneak into a school of fish were a big asset when it came to catching their prey.

Nothosaurus is one example of a nothosaur. Others such as Ceresiosaurus, Pachypleurosaurus, and Lariosaurus are also classified as nothosaurs. A good deal of our basic understanding of these marine reptiles comes from Dr. Oliver Rieppel of the Field Museum, Chicago, Illinois. Nothosaurus itself lived in the mid-Triassic, and its name’s meaning is translated as “false lizard.” Scientists have considered two possibilities as to how the animals gave birth to their offspring. The eggs were laid on the sandy shores like modern sea turtles. Or a Nothosaurus would give live birth to its young at sea just as some sharks do today.

Stegosaurus

3D Model of Stegosaurus

You know, it would be kind of unfair not to include at least one dinosaur in this list. (Although, cinema and literature have almost made them overrated.) What is so special or weird about Stegosaurus apart from the fact that it was a dinosaur? Well, it isn’t really. It is primarily included on this top ten list in order to clear up some misconceptions and mysteries surrounding its public consideration. Dwelling in the prehistoric Americas in the late Jurassic period, Stegosaurus had bony plates along its back and small ossicles covering its throat.

In relation to the creature’s mass, it has the smallest brain of all dinosaurs. Speaking of brains, here is another fun fact which some people still may have never heard. For a time, scientists were throwing out the hypothesis that a certain organ located in the tail of a Stegosaurus was responsible for performing some actions in the dinosaur’s posterior end.

However, the mass of nerves or whatever organ it may have been is no longer considered to have been a true brain. As for its renowned plates, scientists have made several speculations as to their function. They could have been for simple body defense when sparring with its peers or evading predators. They might have been for storing up heat during the day to then “burn up” after the sun went down. Or the plates even could have a means to attract mates.

Thylacosmilus

 

 

Artist Rendering of Thylacosmilus

 

Thylacosmilus obviously has the body style of a saber-toothed tiger. Interestingly enough, the animal also happened to be a marsupial. A marsupial is simply an animal which has a pouch of skin in which to carry its newborn young for a period. Modern marsupials include kangaroos and opossums. Living in the late Tertiary period, Thylacosmilus had strong, long-lived family relationships. Any restoration is far from perfect since a full skeleton has never been found.

Tsaidamotherium

Credit: Frontiers of Zoology.

Credit: Frontiers of Zoology.

Considered a pronghorn, Tsaidamotherium lived in the late Tertiary and bears some resemblance to the musk ox of present-day. Its body shape seems related to that of bovines. Tsaidamotherium was a grazing creature like many of its Miocene peers and lived on the Mongolian plains. It possessed one great cylindrical horn ontop its forehead and directly in the center. Another much smaller horn was located directly adjacent to it.

The likely function that its larger horn is supposed to have carried out was perhaps for display to attract a counterpart of the opposite gender. At first glance then, this creature could resemble the description of the mythical beast the unicorn. Dougal Dixon states this same relation in The World Encyclopedia of Dinosaurs and Prehistoric Creatures.

Megatherium

Artist Depiction of Megatherium. Credit: Wikimedia Commons.

 

As the name implies, this brute was a pretty large mammal. It was actually a giant ground sloth related to modern sloths. An inhabitant of South America during the Quaternary period, an adult standing on its hind legs could reach a height of 20 feet. Megatherium was previously regarded as a slow tree ripper. But recent studies show that its great claws might have been used for stabbing and killing. If this was the purpose of its claws, it would make the giant sloth the largest predator of the South American plains.

Scientists discover new iguana species in Fiji island

Working in the Fiji islands, biologists have discovered a new species of lizard. The newly discovered species in an iguana, one of the only four living species of South Pacific iguana.

Unlike other iguanas, this species always has a solid green neck. Image credits: Mark Fraser.

The iguana was found on the island of Gau, a relatively small island with an area of 136.1 square kilometers, which hosts a rich biodiversity. The first time iguanas were found on Gau Island was in 1854, when a survey ship by the name of HMS Herald carried Scottish naturalist John MacGillivray to the Fiji islands. MacGillivray spent his time there detailing his encounters with native wildlife in his journal and describing the species he found. They found several iguanas, comparing what they found to specimens existing at the University of the South Pacific Herpetology Collection, Suva, Fiji and the British Museum of Natural History, London. They learned that they were dealing with three new species of iguanas, which they collectively named the South Pacific iguanas. This one is the fourth.

The Gau iguana has visible physical differences to its counterparts. It’s the smallest of the group, 13 percent smaller than the second smallest species, and 40 percent smaller than the largest species. It also features a distinctive coloring, including green throats on both males and females (in other species, male iguanas never have solid green necks). Researchers say this new species is yet another testament to the stunning biodiversity that Fiji boasts.

“These types of discoveries continue to surprise us in Fiji, where we are showing a much richer reptile fauna than was previously known to exist,” said Robert Fisher, research biologist with the USGS and lead author of the study.

Illustration of Fijian iguanas. Image credits: Cindy Hitchcock, USGS Western Ecological Research Center.

There may very well be many other species (including potential iguana species) on the islands, just awaiting to be discovered. Several islands in the area have never been properly surveyed by biologists.

“We still don’t know exactly how many species of iguana there might finally be on Fiji’s 300 islands,” said Peter Harlow, terrestrial biologist with Taronga Conservation Society Australia. ”Many islands are still to be surveyed. On my first trip to Fiji there was just a single known species, and today we have four species.”

For now, researchers will try to learn more about this new species, figuring out its preferred habitat and behavior. However, just identifying and finding the iguana is not nearly enough — the team also wants to establish a conservation plan for it. Pacific iguanas face numerous threats from habitat loss and invasive species (feral cats, rats, goats, and mongoose). Just a small, isolated parts of the island still remain pristine and undamaged.

Journal Reference: Robert N. Fisher, Jone Niujula, Dick Watling, Peter S. Harlow — A new species of iguana Brachylophus Cuvier 1829 (Sauria: Iguania: Iguanidae) from Gau Island, Fiji Islands,

Iguana sun basking.

Warm-bloodedness shown to be millions of years older than we thought — maybe as old as the dinosaurs

The first warm-blooded animals may have evolved millions of years earlier than believed, researchers at the University of Bonn report.

Iguana sun basking.

Those of you who have a pet lizard or snake probably know how much they like to bask in the sun or a heat lamp. They’re especially fond of doing this in the morning after a cold night. It’s all because of the way they regulate their internal temperature — reptiles rely on external heat to limber them up, as they can’t don’t use their energy to generate heat. You, me, a mouse, or other mammals and birds instead generate heat internally, by burning calories.

Because of this, reptiles are often referred to as cold-blooded, and as warm-blooded. Cold-bloodedness made a lot of sense in the Earth’s past, as mean temperatures were a lot higher back when reptiles were still news. Today, being cold-blooded is ‘cheaper’ in a nutritional sense — these animals need to eat a lot less because their bodies don’t burn anything to keep warm. Having warm blood means you’re more resilient in the face of environmental factors and allows animals a higher metabolic rate (what you perceive as being ‘lively’,) since the extra thermal energy makes biochemical reactions underpinning their activity take place faster.

Until now we’ve believed that the transition from cold to warm blood took place in a four-legged land animal somewhere around 270 million years ago.

“However, our results indicate that warm-bloodedness could have been created 20 to 30 million years earlier,” says Prof. Martin Sander from the Steinmann Institute for Geology, Mineralogy and Paleontology at the University of Bonn.

Since you can’t exactly slap a thermometer onto a fossil and see how warm the original animal was, the team had to use other methods of discerning between cold and warm-bloodedness. Thankfully, the trait leaves behind certain characteristics in the fossils that the team was able to draw on.

Bone-afide data

Warm-blooded animals tend to grow faster than their cold-blooded counterparts, which is reflected in the structure of their skeleton. Bones are a mix of protein fibers (such as collagen) and a material known as bone mineral, a form of hydroxyapatite. Collagen fibers in particular need to be well ordered during bone development since collagen makes them flexible and binds everything together. The more well ordered these fibers are, the stronger the bone becomes — but it also takes more time to grow.

Ophiacodon bones.

The fossils used for the study.
Image credits Shelton, C.D., Sander, P.M., Long, C. R. Palevol (2017).

Since mammals grow faster than reptiles, their bones are also based on a special structure (fibrolamellar) which allows for faster growth without sacrificing strength. And that’s what the researchers looked for.

Teaming up with his PhD student Christen D. Shelton, Prof. Sander analyzed the humerus and femur bones of the long extinct, lizard-like mammal predecessor Ophiacodon. They found that its bones relied on a fibrolamellar structure, suggesting that the “animal could already have been warm-blooded.”

The finding is especially exciting since Ophiacodon is closely related to both reptiles and mammals — it’s just beyond the spot in the tree of life where these two branches diverge. Up to now, we’ve simply assumed cold-bloodedness was the first type of metabolism to develop since today’s reptiles have the longest evolutionary heritage and are all cold-blooded. Warm blood, the theory goes, developed later as mammals evolved further.

But the findings, coupled with other known or suspected cases of warm-blooded ancient animals, could throw this theory into question.

“This raises the question of whether its warm-bloodedness was actually a completely new development or whether even the very first land animals before the separation of both branches were warm-blooded,” says Sander.

It’s currently just speculation, and the team will need to look at a lot more fossils before they have a clear picture. But if their theory is correct, we would have an interesting couple of questions on our hands: when, and why, did reptiles forgo warm blood?

The paper “Long bone histology of Ophiacodon reveals the geologically earliest occurrence of fibrolamellar bone in the mammalian stem lineage” (original title “L’histologie d’os longs d’Ophiacodon révèle l’occurrence la plus précoce d’os fibro-lamellaire dans la lignée souche mammalienne) has been published in the journal Comptes Rendus Palevol.

The Crocodilian Revolution: amazing myths and facts about crocodiles

Almost every time I stop by a crocodile enclosure in a zoo, I hear people wondering if these are real animals or plastic models. Captive crocodilians (crocodiles, alligators and their less-known relatives such as caimans) don’t move that much. And this “laziness” has fooled people for centuries.

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A female Cuban crocodile given a piggyback ride by her long-term male partner. Credits: Vladimir Dinets.

Deceivingly Clever

Virtually every popular or scientific description of crocodilians, from Herodotus two thousand years ago to school textbooks of the 1990s, calls crocodilians not just lazy, but stupid (even if more polite or scientific-sounding words are used). When I started my research on crocodilian behavior ten years ago (as a Ph.D. student at the University of Miami, upon a suggestion by my adviser Steven Green), I shared this misconception.

There were some dissenting voices. In 1935, E. A. McIlhenny described some really interesting behaviors; in the 1960s L. Garrick with colleagues discovered a complex signaling system used by crocodilians. But McIlhenny wasn’t a professional zoologist, so his accounts (known today to be entirely accurate) were distrusted by scientists, as were other unusual claims scattered in even older literature. And Garrick, content with discovering some cool things such as crocodilians using infrasound (acoustic vibrations too low for humans to hear), didn’t try to study the behavior of these animals more broadly.

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A mugger crocodile trying to lure some egrets by offering them a stick for nest building. Credits: Vladimir Dinets.

I knew that crocodilians were the only large non-marine animals to survive the mass extinction that wiped out all non-avian dinosaurs. More than one crocodilian lineage managed to survive the catastrophe (the split between crocs and gators pre-dates it). I intuitively felt that there had to be something special about them. But I had no idea what it could be, and scientific literature of the time wasn’t much help.

We shouldn’t be too critical of scientists. Studying crocodilian behavior is a zoologist’s nightmare. Much of it can’t be seen in captivity, but observing it in the wild is difficult and sometimes dangerous (in the last ten years, three crocodilian researchers have died in the line of duty). Crocodilians inhabit murky waters, mosquito-infested swamps and impenetrable rainforests. They are mostly nocturnal, and many have become obsessively shy after decades of overhunting. They are specialized ambush predators, with numerous adaptations (such as the most sophisticated heart in the animal kingdom) allowing them to conserve energy, in part by not moving too much. For example, they don’t hunt very often: being cold-blooded, they eat about ten times less than mammals of the same size (their ancestors were warm-blooded and more active, but that was over a hundred million years ago). It’s not unusual to watch a crocodile all day and never see it move, so you need a lot of patience and endurance.

Crocs in the Night

So I became pretty much the first zoologist to systematically observe crocodilians in the wild at night. I began with a relatively easy species, the American alligator, and then studied over twenty others. And it worked. Within a week I began discovering new things, and this exhilarating marathon of discovery just never ended. In five years I got my Ph.D.; it took me four more years to follow up on some leads that were outside the scope of my thesis, and to publish everything (including a popular book Dragon Songs check it out on Amazon). By that time the subject of crocodilian behavior was no longer a scientific swamp: researchers all over the world are now studying it and making one discovery after another.

So, what have we learned in the last ten years?

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Dancing American alligators. Credits: Vladimir Dinets.

Crocodilians are not stupid. They have relatively small brains, but, just like in birds, these brains are organized very differently from mammalian brains: their volume is utilized more efficiently. These animals are smart and have very complex behavior, instinctive and learned.

They use a sophisticated, flexible communication system. It is a combination of sounds, infrasound, chemical and visual signals, produced by unusual and still poorly understood physical mechanisms. This system can be easily optimized to work in a broad variety of habitats, from overgrown marshes to flooded forests to large open lakes. Crocodilian “language” is so perfect that for the last 70 million years it hasn’t changed much: alligators and crocodiles still largely understand each other.

They are deadly hunters, second only to humans in versatility. Their hunting techniques are only partially known, but we have found that they can hunt as effectively on land as underwater, cooperate with each other (for example, chase prey into an ambush, or form a chain to drive schools of fish into shallows), and use lures. Alligators and crocodiles that live near egret rookeries often float with little sticks on their snouts during the birds’ nest-building season. If an egret looking for building material tries to pick up the stick, it promptly gets snatched. But they are not strictly predatory: they can eat fruit and even be important seed dispersers for some tree species.

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Baby alligators raised in mixed creches love to ride on the backs of their older friends. Credits: Vladimir Dinets.

They are surprisingly social, particularly gators. American alligators gather on spring nights to dance and then sing in choruses in the morning. They are promiscuous, but often have preferred partners and mate with them year after year. Crocodiles have a more hierarchical social system… but this aspect of crocodilian lives still needs a lot of research before we understand even the basics.

They can be excellent parents. In some species both mother and father protect and feed the brood; in others multiple females bring their babies together into a crèche and take turns watching over it.

And they can be playful, friendly, even funny. They play with toys, with each other, and with other animals such as otters. They can become tame and form strong bonds with people. One amateur naturalist in Costa Rica rescued a wounded crocodile, and the animal became his faithful friend: for many years the man and the huge crocodile played together and even pulled little practical jokes on each other.

But don’t try that at home. They might look like plastic models, but they can be very fast, and you can’t presume to be smarter than them.

This article was written by Vladimir Dinets, of the University of Tennessee, Knoxville. He has spent a decade studying the behavior of crocodiles, evaluating their habits and noting playful interactions and complex behaviors.

biofluorescent turtle

First biofluorescent reptile found is a ‘glowing’ neon red turtle

“Hey, what did you find” “We found a bio-florescent turtle!”, a researcher triumphantly declared. David Gruber, a biologist at City University of New York, and colleagues made the find while diving in the Solomon Islands this July. Previously, researchers have found ever growing evidence of bio-luminescence and bio-fluorescence in the animal kingdom, from coral to seahorses, but this was the first time anyone has laid sight on a glowing reptile.

Glow in the dark animals

You can find bioluminescent life forms everywhere on the planet. On land, glowing species of fungus feed on rotting wood, creating the eerie nighttime phenomenon known as foxfire.  Of course, the most famous luminescent creatures are fireflies. Glow worms are also insects — they’re the larvae of various species of flies and beetles. But the most glowing animals are found in the ocean, not on land. Most of these  creatures live well bellow the water’s surface in the twilight or euphotic zone where sunlight barely creeps in. Some of it does, though. Since light is comprised of many wavelengths, some get absorbed by the sea water (red, orange and yellow) while other frequencies make it through (bluish-green). This light is absorbed by some luminescent creatures, then beamed back at 440 to 479 nanometers.

biofluorescent turtle

Although it takes many guises in nature, bioluminescence serves the three basic purposes of “finding food, finding mates and defending against predators,” says Edie Widder, co-founder, president and senior scientist at the Florida-based Ocean Research and Conservation Association (ORCA). It’s proven to be a good tactic seeing how scientists estimate 80 to 90 percent of deepwater, oceanic life has developed the ability to produce light.

In most cases bioluminescence is generated when a light-emitting molecule, called luciferin, chemically reacts with oxygen in the presence of an enzyme, called a luciferase or a photoprotein.  The emitted light is called ‘cold light’ because it wastes little heat, much like an LED – just better. Biofluorescence is different from bioluminescence, though despite to the untrained eye it may seem the same. Bioluminescent animals produce their own light, while biofluorescent animals simple reflect glowing halos.

Gruber found the biofluorescent turtle completely by accident. When he and colleagues spotted the creature, it looked like an underwater UFO. Later, researchers managed to find other such turtles, called hawksbills, kept by some locals in captivity. After careful study, they found the animals glowed in red.

turtle biofluorescent

LUMINESCENTLABS.ORG VIA DAVID GRUBER

It’s believed the hawkbill evolved this ability for camouflage, which doesn’t sound right if you think about it. During the day, they’re very hard to spot, but the same at night too since the turtles hang out around coral which is florescent as well.

One might wonder what took so long to identify the turtles as florescent. Apparently, in shallow waters  not enough blue light to create the “glow” effect.  When you shine a blue light directly onto their shells, however, it glows in bright neon red and green. Unfortunately, there’s another reason why we’ve barely discovered the first biofluorescent reptile. Hawkbills are endangered and some of the rarest on the planet.

“Why is it that we know so little about these amazing animals?” Gruber asks. With renowned interest, maybe we’ll find out.

Scientists find the earliest creature to stand tall on four legs

About 260 million years ago, this pre-reptile might not have looked like much. With its knobby face and about as big as a cow, Bunostegos akokanensis was actually pretty remarkable. According to a new analysis, it was actually the first creature to walk upright on all four legs, maintaining a fully erect gate.

Scientific Reconstruction of Bunostegos akokanensis. Image via Wikipedia.

“Imagine a cow-sized, plant-eating reptile with a knobby skull and bony armor down its back,” said co-author Linda Tsuji, of the Royal Ontario Museum. She and her co-authors discovered the fossils in Niger with a team of paleontologists in 2003 and 2006.

Dogs and reptiles both have 4 legs, but they walk differently. Reptiles generally have their legs on the exterior of their body, while dogs have their legs right under them. But ironically, this posture was first developed by a pre-reptile.

“We don’t see upright posture, with the legs underneath the body, in both the forelimb and the hindlimb in a single animal until much later, in mammals and in dinosaurs,” Morgan Turner, a Ph.D. student at Brown University in Rhode Island and lead author of the study, told The Huffington Post in an email. “Bunostegos is much further back on the evolutionary tree than anything else that exhibits this posture [and] hints at a larger story about posture and locomotion evolution… The anatomy of Bunostegos is unexpected, illuminating, and tells us we still have much to learn.”

Artist’s rendering of Bunostegos, a cow-sized, plant-eating reptile that roamed the ancient central desert of Pangea more than 250 million years ago. Image credits: Marc Boulay.

Walking upright may have provided the creature with some major advantages – first of all, it would have allowed it to walk longer distances, a very useful ability in the deserts of the supercontinent Pangaea where it lived.

“Here’s this big, cow-sized animal in this very arid region,” Dr. Nick Fraser, vertebrate paleontologist at the National Museums of Scotland, who was not involved in the study, told The Huffington Post in a telephone interview. “You don’t think of big herbivores in arid regions. What was going on there? Do we really understand what the climate was?… The more we learn about this creature, the more we will learn about what appears to be an isolated environment in the center of Pangea.”

The study, which was published in the Journal of Vertebrate Paleontology, detailed an analysis of fossilized Bunostegos, including those of the shoulder, the elbow, the forelimb bone known as humerus and another forelimb bone known as the ulna. Analysis on how the bones fit together show that the animal walked upright.

“Aspects of the anatomy of the shoulder and the forelimb indicate that the humerus could not have jutted out in a ‘sprawling’ posture,” Dr. Linda Tsuji, contract assistant curator at the Royal Ontario Museum in Canada and a co-author of the study, told The Huffington Post in an email, “and in Bunostegos we see limited motion at the elbow joint, which is an indication of upright posture in other animals.”

 

 

Artist impression of the newly discovered Ikrandraco avatar. Image: Scientific Reports

Ancient flying reptile was a cross between dragon and pelican

Artist impression of the newly discovered  Ikrandraco avatar. Image: Scientific Reports

Artist impression of the newly discovered Ikrandraco avatar. Image: Scientific Reports

Paleontologists have discovered a new pterosaur species in 120-million-year-old rocks at two sites in northeastern China.  The flying reptile was dubbed Ikrandraco avatar, where draco is Latin for “dragon,” and Ikran are the pterosaurlike flying beasts depicted in the 2009 blockbuster Avatar.

The ancient reptile was described in paper published in the journal Scientific Reports as having a deep lower jaw with a a thin, crescent-shaped keel.  At the end of this bony keel, the researchers note a peculiar hook-shaped projection – an unique feature never before seen in any other pterosaur or vertebrate for that matter – that might have served as an anchor for soft tissue. These suggest that the Ikrandraco may have sported a pelicanlike throat pouch which the flying reptile would have used to carry fish gleaned from lakes or other waters.

I’m note sure how much of the artist representation from above is speculative art or factual representation. If the latter’s the case, then damn this Ikrandraco was one interesting beast!

 

 

 

Crocodilians use sticks to attract prey

  • Two distinct groups of crocodilians have been reported to use tools for hunting
  • They balance sticks on their snouts, baiting birds who want to use the sticks for nests
  • Crocodiles actively search for the sticks (which are usually rare) and do this more often during the birds’ mating season

Mugger crocodile (Crocodylus palustris) at Madras Crocodile Bank, Tamil Nadu, India, with sticks on its head. Image credits: Dinets et al. (2013).

It’s been known for quite a while that the usage of tools isn’t restricted to humans. Monkeys (of course) also use tools, but this type of behavior has also been reported in other species, including crows, dolphins, elephants and otters. Now, a new study has reported that crocodiles and alligators also use sticks to attract prey.

In recent years, reptile research has provided some stunning results, showing that they are not only cold-blooded efficient killers, but that they exhibit a myriad of remarkable behaviors. Play behaviour, complex social interactions, gaze recognition, pair-bonding and monogamy, social hunting, speedy learning abilities and good memories – they have all been reported in reptiles.

Now, another very interesting unexpected adaptation has been demonstrated across these groups: tool usage.

As described by Dinets et al. (2013), Mugger crocodiles Crocodylus palustris in India and American alligators Alligator mississippiensis in the USA have been observed to lie, partially submerged, very close to birds they want to hunt, with sticks balanced carefully on their snouts. Birds want to take the sticks to use them in their nests and… let’s just say it usually has a very bad ending for the birds.

But what’s remarkable is that this occurrence of stick usage by crocodilians isn’t random! Stick displaying took place consistently more often with crocodiles living closer to rookeries, and it also took place more often during mating season – when birds are more inclined to construct nests. It’s also noteworthy that sticks are pretty rare in this type of environment – the reptiles actively search for them, especially during the birds’ mating period.

Baiting behavior was demonstrated before in archosaurs (the big group of species which includes crocodiles, birds and all extinct dinosaurs). Green herons (Butorides virescens) often do it: they use feathers, twigs and even berries and bits of bread to attract fish, while burrowing owls (Athene cunicularia) use mammal dung to attract dung beetles. Also, anecdotal reference suggests that crocodiles also use fish fragments to attract birds. But the fact that this has been consistently reported in two separate groups seems to suggest that this type of behavior is mainspread.

If you think about it, crocodiles have been around for over 70 million years – since the Cretaceous. They are incredibly well adapted to the environment, being able to live as scavengers and survive for months without food. They can even go into a state of hibernation when conditions aren’t favorable, waking up when things are looking up. So it makes sense that they learned a trick or two about hunting.

World’s oldest tootache revealed in ancient reptile fossils

The Labidosaurus Hamatus jaw examined

Paleontologists turned into dentists after an examination of the fossilized jaw of a reptile from the Paleozoic era revealed what’s considered to be the world’s oldest tootache.

Dated back 275 million years ago, the Oklahoma found Labidosaurus hamatus must have had some serious issues with its sugar tooth, as researchers  observed missing teeth and  eroded bones in its jaw, which poissed them to dwell a bit further. Led by Robert Reisz, the chair of the Department of Biology at the University of Toronto Mississauga, scientists decided to investigate further with a CT-scan – they  soon found evidence of a major infection that had caused the loss of several teeth and a massive abscess.

“Not only does this fossil extend our understanding of dental disease, it reveals the advantages and disadvantages that certain creatures faced as their teeth evolved to feed on both meat and plants,” said lead researcher Robert Reisz. “In this case, as with humans, it may have increased their susceptibility to oral infections.”

What apparently happened, researchers conclude, is that the reptile lost a tooth, which consequently became a hole, and through that hole a heck load of bacteria flooded and extended itself to other adjacent healthy teeth. This is exactly what Reisz was pointing out, since it shows how important evolution influenced this particular case. Because the Labidosaurus’ diet was plant based, ergo a lot of chewing was involved, it gradually evolved from the primivitive dental setup in which teeth were loosely attached to the jaws and continuously replaced (see sharks) to teeth that were strongly attached to the jaw, with little or no tooth replacement.

The downside to this, however, is pretty evident as outlined, which in way explains why humans are also very susceptible to dental infections if a parallel is to be made.

“Our findings suggest that our own human system of having just two sets of teeth, baby and permanent, although of obvious advantage because of its ability to chew and process many different types of food, is more susceptible to infection than that of our distant ancestors that had a continuous cycle of tooth replacement,” Reisz said.

The study is detailed online in the journal Naturwissenschaften — The Science of Nature.

The amazing Tuatara

The tuatara is not an iguana, it’s not a lizard, and it is very, very different than any other reptile alive today on Earth. In fact, recent studies suggest that it’s pretty different from any other vertebrate. It’s home is in New Zealand, which is known for eccentric life forms of all kinds: the kiwi, with long whiskers and feathers just like fur, the kakapo, the parrot that can’t fly and looks like an owl, and the giant weta, a cricket as big as your fist. However, as amazing and special as these animals are, they fade in comparison to the tuatara.

About 80 million years ago, the supercontinent Gondwana split up, leaving life on this paradise island evolutionary separated from the rest of the world. The tuatara is about 16 inches long, and it’s practically a living fossil – it hasn’t changed significantly in hundreds of millions of years. It has a third eye, the legendary but unexplained pineal eye, located on the forehead and used for registering light intensity and regulating body temperature.

But what is extremely weird is that a few regions of the tuatara DNA are evolving at an incredible speed, probably with the fastest mutation rate ever in vertebrates. The rapidly changing DNA sequences are limited to so-called neutral regions of the tuatara’s DNA, and affect rather fillings and not the basic “blueprint” of the tuatara. They are also very different from reptiles too.

“Their biology is quite distinctive,” said Charles Daugherty of the Allan Wilson Center for Molecular Ecology and Evolution at Victoria University of Wellington in New Zealand. “They have a unique type of hemoglobin, and their enzymes are set to function at lower temperatures than in most reptiles.” As a result, tuataras remain active at night, and in weather just a few degrees above freezing, said Dr. Daugherty, “at temperatures at which most reptiles couldn’t survive.”

But the tuatara gets even more awesome. They routinely live to 100 years, and often go above 150 or even 200; they also live it up – females can reproduce up until 80-100 years. They’re also mean and like to show off, and even fight when necessary

“They have crests they can inflate, to make them look big, and they stand very tall and start mouth-gaping at each other,” said Dr. Godfrey. “If one male doesn’t get the message, it will escalate into a physical fight.” They tear at each other’s crests and toes, they trade parasites. “During mating season, you can see the bright orange patches of mites on their necks,” said Dr. Godfrey. “It’s quite spectacular.”

Today, there are less than 50.000 tuataras, all of which are considered to be a national treasure.