Tag Archives: lizard

Looking ‘weird’ saves robot lizards from predators

One of the robo-lizards placed 2-3 meters atop a tree to lure predators. Credit: Terry Ord.

Nature is often riddled with paradoxes. On the one hand, you have species that expend a great deal of energy to embellish their appearance to attract mates or to communicate with peers. On the other hand, the same traits can make these individuals sitting ducks to predators. It’s on this tightrope, anchored by natural selection on one end and sexual selection on the other, that many species dance.

However, this is an oversimplification. New research from the University of New South Wales (UNSW) shows that standing out in appearance doesn’t necessarily invite predators for dinner. In fact, as the field experiments showed, being too flashy may actually dissuade predators.

For their study, the researchers led by Terry Ord, an evolutionary ecologist and Associate Professor at UNSW’s School of Biological, Earth and Environmental Sciences, placed a staggering 1,566 robotic lizards on trees on the campus of a university in Borneo.

The robot consisted of a box filled with motors and microelectronics, on top of which sat a plasticine draco lizard that was cast out of a realistic model. The robots performed one of three functions: a conspicuous visual display, a conspicuous ornament, or remained cryptic. The latter acted as a negative control, in that the researchers assumed that this state would be least predated by the many birds, cats, and snakes around the campus. The putty-like plasticine is great for assessing predation because you can clearly see all the pecking, biting, and scratching left by attackers.

Draco lizards are known as ‘gliding lizards’, as they have retractable gliding membranes. They communicate with extendable throat-fans, called dewlaps, which are diverse in color, shape, and size among species. Ord fitted a colorful plastic gliding membrane to each of the many robot lizards that littered the trees at the Kota Samarahan campus in Borneo, which was displayed or retracted at regular intervals by a servo motor controlled a micro-controller, mimicking real draco behavior.

Ord and colleagues embarked on this research looking for clues as to how exactly visible predator warning systems evolve in prey systems. Some animals employ bright, contrasting colors, such as the black and yellow of many wasps and the red of ladybird beetles — a phenomenon known as aposematism — as if to advertise ‘I’m not good to eat. Moreover, if you do decide to eat me, you will die in horrible pain!’

But, you see, this is a chicken or the egg dilemma. How did predators know to avoid these prey that displayed warning systems in the first place?

“There’s a paradox, when the first prey evolves a conspicuous signal, the predators are not going to know what that signal is about, the prey are going to get attacked, and they’re not going to reproduce to pass their genes onto the next generation,” Ord told Cosmos Magazine.

“How do you actually get from point A – that’s being cryptic and hiding – to point B, which is being conspicuous and deliberately advertising that you’re not profitable to predators.”

Instead of finding that the flashiest draco lizard decoys had their heads chopped off in overwhelmingly large numbers compared to controls, the researchers actually found that “robotic prey that performed a conspicuous display were equally likely to be attacked as those that remained cryptic.” Furthermore, predators avoided attacking robotic prey with a fixed, highly visible ornament, the researchers noted. In other words, the oddest animals were visited by predators the least.

Ord and colleagues refer to the deterrence of predators by stand-out features as “predator conservatism”, challenging the entrenched notion that conforming prey that looks like everyone else makes the animal safer.   

The findings appeared in the journal Proceedings of the Royal Society B.

Newly-discovered fossil lizard shows how uncertainty can lead to better science

A skull unearthed in 1971 and stored at Yale’s Peabody Museum of Natural History has finally been studied and described — uncovering a new species.

Lizard skull fossil is new and 'perplexing' extinct species
Left lateral view of the Kopidosaurus perplexus skull. Image credits Simon Scarpetta.

Lizard fossils aren’t particularly plentiful, as their bones tend to break apart rather easily. Most of the fossils we do have of them, therefore, come as isolated fragments, not complete specimens. That’s what makes the discovery of the present fossil, a beautifully-preserved skull about one inch long with a mouth full of sharp teeth, all the more exciting. Based on the skull, University of Texas at Austin graduate student Simon Scarpetta described a new fossil species.

New lizard on the block

“Anytime you find a skull, especially when you’re trying to figure out how things are related to each other, it’s always an exciting find,” Scarpetta says.

Scarpetta found the skull back in 2007 and brought it back to the Jackson School of Geosciences at The University of Texas for study. It turned out to be a completely new species, which he christened Kopidosaurus perplexus. The first half of its name is a reference to the lizard’s teeth and their distinct curvature — a kopis was a type of curved sword used in ancient Greece. The second part is a nod to how “perplexing” it’s been to determine where the lizard fits on the tree of life, according to Scarpetta. It simply fits in several spots equally well.

K. perplexus could belong to one of two families of lizards, but we don’t have enough information to tell which is the right one. Adding to the uncertainty is that the relationship between these groups is different between the different evolutionary trees we currently have at our disposal. Scarpetta looked at three of them, each constructed by different researchers studying reptile lineages based on DNA data, and found several places into which the ancient lizard could fit snugly.

As such, the species raises an important point for paleontology: just because a species fits on one branch of the tree of life doesn’t mean that it’s supposed to be there, or that it doesn’t fit on another one.

“The hypothesis that you have about how different lizards are related to each other is going to influence what you think this one is,” Scarpetta said.

For fossils, where DNA information isn’t available, paleontologists rely on the animal’s morphology (anatomical structure) to determine how it relates to other long-dead species. In essence, because animals evolve from one another, related species will share structural elements — like how cars of a particular brand share particular design elements, for example. The more such similarities between two specimens, the more likely it is that they’re related.

Lizard skull fossil is new and 'perplexing' extinct species
A computer tomography image of the skull in left lateral view. Image credits Simon Scarpetta.

Scarpetta created a digital scan of the skull in order to better study it. He found certain details that helped him determine this was a new species altogether, but some elements overlapped with features from several other lizard lineages. All of those lineages, he explains, belong to the Iguana group, which includes today’s chameleons, anoles, and iguanas. He later compared the skull to several Iguana evolutionary trees — on each, the animal fit equally well in two general spots, he explains.

It’s far from the only species that could easily fit into multiple places on the tree of life, he adds. But the study goes a long way towards showcasing how complicated this process can be, and why accepting a degree of uncertainty in our findings can help lead to better, more accurate science in the long run.

The paper “Effects of phylogenetic uncertainty on fossil identification illustrated by a new and enigmatic Eocene iguanian” has been published in the journal Scientific Reports.

Florida lizard was so constipated its 80% of its body weight was poop — and pizza is to blame

We’ve all had bad tummy days, but nothing comes even close to this.

Image credits: Florida Museum / Edward Stanley.

“When we caught it, we just assumed the animal was ready to lay eggs,” said Natalie Claunch, a Ph.D. candidate in the University of Florida School of Natural Resources and Environment. “But when we went to feel for eggs, it just felt like it was full of Silly Putty.”

Claunch is studying invasive lizard populations in Florida, and she was shocked to find the unusual curly-tailed lizard. Along with Edward Stanley, director of the Florida Museum’s Digital Discovery and Dissemination Laboratory, she CT-scanned the lizard and found a massive fecal mass lodged in its enlarged stomach. It was so large that the surrounding organs were starting to atrophy, and the poop made up for almost 80% of its body weight.

“I was blown away by how little room there was left for all the other organs ­– if you look at the 3D model, it has only a tiny space left over in its ribcage for the heart, lungs and liver,” Stanley said. “It must have been a very uncomfortable situation for the poor lizard.”

The record poop-to-body ratio was almost six times larger than the previous one, held by a Burmese python. The unfortunate lizard was unable to digest the nutrient-depleted bolus and was essentially starving because she couldn’t eat more.

The culprit? Pizza.

Curly-tailed lizards are native to the Bahamas and Cuba, and they were originally introduced to Florida in the 1940s to eat sugarcane pests. The female lizard was likely hunting insects and other prey when it was lured to a parking lot by pizza grease. Thinking it found an easy source of nutrients, the lizard started gulping the grease, ingesting a bit of sand with each bite of pizza grease. Then, it was unable to digest or expel the digestive bolus, which quickly built up inside of it.

Northern curly tails often successfully pass large amounts of feces, as is seen in this healthy lizard. Image credits: Natalie Claunch.

It’s very unlikely for an animal to suffer this type of problem in nature. Lizards typically only eat small insects and can’t gulp a lot of sand at one time, and if they do, they’re likely to become prey for their own predators. It was once again human activity that paved the way for this to happen.

“New populations are still being reported and discovered – these lizards can hitchhike in cars, plant delivery trucks or boats, so they end up in a lot of disconnected places,” Claunch said. “We have so many invasive lizards in Florida that funding and person-power is typically directed toward ‘high priority’ species that are a direct threat to native threatened or endangered species, or to infrastructure, but the curly-tailed lizards’ successful spread makes it an interesting case.”

The researchers published their findings as a note in the Herpetological Review.

Australian lizard is the first vertebrate seen to lay eggs and give birth in one pregnancy

Researchers at the University of Sydney report observing a three-toed skink (Saiphos equalis) lay eggs and give birth to live babies in the same litter. This is the first time a vertebrate has been witnessed doing so.

Image credits Bernard DUPONT / Flickr.

Three-toed skinks are one of the very few “bimodally reproductive” species we’ve ever found, animals in which some individuals lay eggs and others give birth to live offspring. But we’ve never seen one to do both. This world-first observation could help guide our research into the evolution of pregnancy.

Mixed approach

The lizard is native to the east coast of Australia. Individuals in the northern highlands of New South Wales typically birth live young, while those in and around Sydney lay eggs. Dr. Camilla Whittington at the University of Sydney reports on one of the lizards which lay three eggs and then weeks later give birth to a live baby from the same pregnancy.

“It is a very unusual discovery,” said Dr Camilla Whittington, from the School of Life and Environmental Sciences and Sydney School of Veterinary Science at the University of Sydney, the study’s lead author.

“We were studying the genetics of these skinks when we noticed one of the live-bearing females lay three eggs,” Dr Whittington said. “Several weeks later she gave birth to another baby. Seeing that baby was a very exciting moment!”

She quips that this finding makes the animal, which looks like a tiny snake with tinier legs, one of the “weirdest lizards in the world”.

Oh my god, that’s cute.
Image via Wikimedia.

The team published their observations along with advanced microscopy of the egg-coverings (shells). They explain that the first vertebrates laid eggs, and that some evolved over thousands of years to hold the young inside their bodies as they developed. Eventually, the length of time they did so became longer and led to them giving birth to live offspring.

Mammals are typically associated with this type of reproduction, but there are many modern reptile species that give birth, from turtles and lizards to snakes, crocodiles, and dinosaurs.

However, finding an individual that can both lay eggs and give birth is truly an incredible find. The team likens it to a snapshot in the process of evolution, allowing us to better understand it in action. The team hopes that more research on this animal can help us determine how major reproductive leaps take place in nature.

“Put in the context of evolutionary biology, being able to switch between laying eggs and giving live birth could allow animals to hedge their bets according to environmental conditions,” Dr Whittington adds.

The paper “Facultative oviparity in a viviparous skink (Saiphos equalis)” has been published in the journal Biology Letters.

Fossil Friday: lizard foot trapped in amber helps us better understand fossilization

A new paper describing the foot of a lizard preserved in amber broadens our understanding of the fossilization processes.

The fossil seen under natural light (A, B) and false coloring (C, D).
Image credits H. Jonas Barthel et al., (2020), PLOS One.

The tiny foot belonged to a lizard in the genus Anolis which became trapped in resin around 15 to 20 million years ago. It is very well preserved, with every detail of the limb visible under the microscope.

However, this dandy exterior hides a very different core: the bone inside this foot is heavily decomposed and chemically transformed, with very little of the original structures still present.

Foot for thought

“This is surprising, because we assumed that the surrounding amber largely protects the fossil from environmental influences” says Jonas Barthel, a doctoral student at the Institute for Geosciences at the University of Bonn and first author of the paper.

Every fossil begins with a rapid embedding in a protective material — in this case plant resin, which turned into amber over time. This layer of material protects the biological material from scavengers and microorganisms. After the animal is encased in a protective layer of material, its tissues start being gradually replaced by mineral compounds as pressure from sediments on top compresses everything — in essence, it starts becoming a rock.

“That’s the theory,” says Barthel. “How exactly fossilization proceeds is currently the subject of intensive scientific investigation.”

The fossil described in this study is pretty rare; it’s usually small organisms such as insects that get trapped in resin (which over time becomes amber), not vertebrates (which are larger). It was analyzed as part of a larger research project between the University of Bonn and the German Research Foundation centered on fossilization processes, which has been ongoing since 2018.

The whole piece of amber than encases the limb is about two cubic centimeters in size and was recovered from the Dominican Republic. It belongs to a genus that is still alive today and was housed at the Stuttgart State Museum of Natural History.

For the study, the team asked the Institute for Evolutionary Biology at the University of Bonn to cut the amber down into thin sections to allow for investigation of the fossil inside. The claws and toes inside the amber were very well preserved, the team reports, suggesting that resin had dripped onto the limb. Further investigations at the university’s Institute for Geosciences using micro-computer tomography revealed that the forefoot had been broken in two places. The area around one showed slight swelling, indicative of a fracture that happened prior to fossilization

“This is an indication that the lizard had perhaps been injured by a predator,” says Barthel.

The other fracture, however, seems to have formed after fossilization, and coincides with a tiny crack running through the amber.

Analysis of the bone inside showed that the mineral hydroxyapatite in its tissues had been transformed into fluoroapatite, implying that fluorine penetrated the tissues. Additionally, they found that the collagen in the bones has largely degraded now. In other words, although the fossil seems very well-preserved at first glance, very little of the original tissues remain intact. So far, the researchers were unable to detect complex molecules such as proteins in the fossil.

The team believes that the tiny crack in the amber allowed mineral-rich solutions to filter through into the leg and destroy the organic matter.

“We have to expect that at least in amber from the Dominican Republic, macromolecules are no longer detectable,” says the supervisor of the study, Prof. Dr. Jes Rust from the Institute for Geosciences.

It was not possible to detect more complex molecules such as proteins, but final analyses are still pending. The degradation processes in this amber deposit are therefore very advanced, and there is very little left of the original substance.

Amber is generally considered to be an ideal preservative, as a fully-encased fossil will be completely isolated from the environment. However, in the case of this fossil, the team was surprised to see that the amber might have actually promoted the degradation of soft tissues. Acids in the original tree resin have probably reacted with apatite in the bones in a process similar to tooth decay, the researchers conclude.

The paper “Fluoridation of a lizard bone embedded in Dominican amber suggests open-system behavior” has been published in the journal PLOS One.

Lizard-like 309-million-year-old fossil is oldest evidence of parenting

 An artist’s impression of Dendromaia unamakiensis.

More than 300 million years ago, during the Carboniferous period, Nova Scotia was a subtropical swamp dominated by lycopsids, an ancient moss-like plant. In the hollowed-out stump of one of these lycopsids, an adult lizard-like creature and her young likely made their den, until a grave storm flooded the area with sediments. The tragic event killed the creatures, but in the process also trapped the pair in an intertwined embrace — it is the oldest example of a creature caring for its young that scientists have found so far.

The amazing discovery was made in 2017 by Brian Hebert, a local fossil enthusiast, who contacted Hillary Madin, an assistant professor at Carleton University, Canada. The two recently published a paper describing the new species, known as Dendromaia unamakiensis, whose name is derived from the ancient Greek words for ‘tree’ and ‘mother’ and the Mi’kmaq’ indigenous people’s name for Cape Breton Island, where the fossil was found.

According to the researchers, the species is a varanopid, an extinct family of amniotes that resembled monitor lizards, which some claim to be an early lineage leading to mammals.

Fossil of Dendromaia unamakiensis adult and its young; the latter can be seen in the picture on the right, near the bottom right corner. Credit: Maddin et al.

The Dendromaia adult was no longer than 20 centimeters from the tip of the snout to the base of the tail. Behind the adult’s hind legs and encircled by its tail lies the fossilized skull of a juvenile of the same species.

This side-by-side positioning suggests that the adult was a parent — after all, it would be quite the coincidence for the two creatures, an adult and juvenile, to die and fossilize together randomly. In effect, this would make the 309-million-year-old fossil the oldest evidence of parental care to date — a good 40 million years earlier than previously thought.

“This specimen adds to growing evidence that parental care was more widespread among Palaeozoic synapsids than previously thought and further provides data permitting the identification of potential ontogeny-dependent traits within varanopids, the implications of which impact recent competing hypotheses of the phylogenetic affinities of the group,” the authors wrote in their study.

Although it’s impossible for the researchers to derive definite conclusions about such complex behavior from the fossil record, the evidence is pretty strong that the adult and youngling interacted.

Today, many birds, mammals, and lizards invest considerable time and resources into protecting, nurturing, and rearing their offspring. In some species, particularly social animals, parenting can be incredibly demanding, as adults invest heavily to teach their young how to forage. Humans, for instance, are born into this world completely helpless and dependant on their parents for survival.

We tend to view many ancient animals as primitive. However, this fossilized duo suggests that even back then creatures that predated the dinosaurs behaved in many ways like modern animals.

It’s not clear at the moment whether parenting evolved multiple times in history or it surfaced a single time in a common ancestor shared by Dendromaia and all the modern animals that care for their young today. But, if anything, this is a good opportunity to appreciate family life. Parenting has been around for at least 300 million years so it’s definitely good for something.

The findings appeared in the journal Nature Ecology & Evolution.

The world’s first gene-engineered reptiles are all albinos

Researchers report producing the first gene-edited reptiles ever.

An albino lizard hatchling.
Image credits Doug Menke.

A new study reports on the use of CRISPR-Cas9 to create albino brown anole lizards (A. sagrei). No other team has successfully applied gene-editing techniques to reptiles. The study also shows that the gene-edited lizards can also pass the modified genes for albinism to their offspring.

CRISPy lizards

“For quite some time we’ve been wrestling with how to modify reptile genomes and manipulate genes in reptiles, but we’ve been stuck in the mode of how gene editing is being done in the major model systems,” says corresponding author Doug Menke, an associate professor at the University of Georgia.

“We wanted to explore anole lizards to study the evolution of gene regulation, since they’ve experienced a series of speciation events on Caribbean islands, much like Darwin’s finches of the Galapagos.”

In most model species (such as lab rats, for example) CRISPR-Cas9 is employed by injecting gene-editing vectors into freshly fertilized eggs or single-cell zygotes (i.e. after fertilization). However, this approach can’t be used on reptiles, as they employ an internal fertilization process making it hard to predict when an egg becomes fertilized. It’s also hard to isolate a single-celled embryo from momma lizard, which means we can’t transfer it out into a lab dish and work on it.

Menke and his team, however, noticed that the transparent membrane over the species’ ovary allowed them to track all of the developing eggs, including which eggs were going to be ovulated and fertilized next. They then decided to inject the CRISPR elements into unfertilized eggs within the ovaries.

“Because we are injecting unfertilized eggs, we thought that we would only be able to perform gene editing on the alleles inherited from the mother. Paternal DNA isn’t in these unfertilized oocytes,” Menke says.

He explains that it took three months for the lizards to hatch, and says that the procedure is “a bit like slow-motion gene editing”. By the end, the researchers found that about 6% to 9% of the oocytes, depending on their size, produced offspring with gene-editing events. Around half of the edited lizards held modified genes from both parents. The findings indicate that the CRISPR components remain active for several days, or even weeks, within the unfertilized eggs.

In some other model animals, CRISPR-Cas can have efficiencies up to 80% or higher, which would make the present 6% seem like a paltry amount, Menke explains.

“But no one has been able to do these sorts of manipulations in any reptile before,” he says. “There’s not a large community of developmental geneticists that are studying reptiles, so we’re hoping to tap into exciting functional biology that has been unexplored.”

The team decided to use albinism genes for the study because they result in an obvious physical trait (loss of pigmentation) without being lethal to the animal. Secondly, they wanted to use the lizards as a model to study how the loss of pigmentation impacts retina development, as humans with albinism often have vision problems. The anole lizards are ideally suited for this: their eyes have a fovea, a pit-like structure in the retina that underpins high-acuity vision, which humans share, but most of our main animal models lack.

Ultimately, this gene-editing technique could be translated for use in other animals, Menke adds.

“We never know where the next major insights are going to come from, and if we can’t even study how genes work in a huge group of animals, then there’s no way to know if we’ve explored everything there is to explore in the realm of gene function in animals,” Menke says.

“Each species undoubtedly has things to tell us, if we take the time to develop the methods to perform gene editing.”

The paper “CRISPR-Cas9 Gene Editing in Lizards through Microinjection of Unfertilized Oocytes” has been published in the journal Cell Reports.

Anolis scriptus. Credit: Colin Donihue.

Hurricane-braving lizards get to grips with natural selection

Anolis scriptus. Credit: Colin Donihue.

Anolis scriptus. Credit: Colin Donihue.

Scientists have found an example of natural selection in action during unexpected circumstances: in the aftermath of a devastating hurricane, lizards that were better equipped for clinging onto branches were more likely to survive and, hence, pass on their genes.

Hurricanes can be devastating to ecosystems, causing many premature deaths and ruining habitats. Although it can be heartbreaking to lose one’s home and belongings, most of the time humans are able to evacuate in time before a hurricane beats on their doorstep. Some animals can sense the danger and flee or fly away, but many get trapped in the eye of the storm. For instance, the red-cockaded woodpeckers in South Carolina’s Marion National Forest were almost wiped out by Hurricane Hugo in 1989.  About 60 percent of the 500 groups of birds perished and 87 percent of the trees containing cavities where they lived were destroyed.

Hurricanes Irma and Maria, which hit the Caribbean, Puerto Rico, and the US Virgin Islands in September 2017, were even more powerful and devastating. Colin Donihue and colleagues at Harvard University had, incidentally, just finished their survey of anole lizards (Anolis scriptus) on the adjacent West Indies islands of Pine and Water Cay, located on the eastern end of Grand Bahama Island, Bahamas.

The scientists decided this was an excellent opportunity to study the direct impact of natural disasters on the local wildlife, so they decided to immediately return to the islands once the storm cleared.

The team focused on the difference in limb length and toepad surface area of the lizard populations before and after the hurricanes. These characteristics are believed to be critical to the animals’ clinging abilities and have been associated with habitat use and mode of locomotion.

Interestingly, the lizards that survived the hurricane onslaught on both islands had significantly larger toe pads and forelimbs, and shorter hind limbs than the population surveyed prior to the storm.

This comparative advantage among the A. scriptus surviving population is illustrated by a video filmed by the researchers, which shows how lizards grip branches. Longer forelimbs allow the lizards to have a better grip on tree branches, making them more resilient in the face of hurricane winds. However, the researchers note that the posture that the lizards adopt when braving powerful winds is also important — and in this situation having longer back legs would be a disadvantage because they increase the surface area that can be blown by the winds.

Essentially, what the researchers just witnessed is a fine example of natural selection in action. These surviving lizards will breed and, as such, the two islands will be filled with populations where there are more individuals that are able to withstand a hurricane. Some animals, however, aren’t as lucky because whole populations can be wiped out during natural disasters before they have the time to adapt.

Climate change is expected to increase the intensity and frequency of natural calamities such as hurricanes in the future. Studies like these allow scientists to gain a better understanding of evolutionary dynamics, which we’ll need to factor in when preparing for climate change mitigation action.  

The findings appeared in the journal Nature.

Bluetongue.

Australian skinks will literally stick their tongues out at predators — and it works!

When in doubt, stick your tongue out at them!

Bluetongue.

“You asked for it punk!”
Image credits Shane Black.

Skinks in the genus Tiliqua are pretty inconspicuous as far as lizards go. They don’t really like to draw attention to themselves, and they’re decidedly lizard-shaped. New research shows that when their unassuming nature fails to garner the peace of mind they desire (from predators), the skinks fall back to a surprising — and surprisingly effective — last-ditch defense: their tongues.

Their what now?

Bluetongued skinks are fairly widely spread throughout Australia, eastern Indonesia, and Papua New Guinea. They’re omnivorous, mediumly-sized lizards that primarily rely on their camouflage to keep out of sight. When under attack by a determined predator, however, they make an effort to stand out: the skinks open their mouth suddenly, as wide as they can, to reveal a brightly-colored blue tongue. Not to make them self-conscious but these tongues must be a sight to recoil from — because that’s exactly what predators do.

The behavior is used as a last line of defense to protect the skinks from attack, writes Martin Whiting, the study’s corresponding author, in a press release. The research revealed that the tongues are very reflective in the UV spectrum, and that they are more UV-luminous towards the back. Some of the lizards’ main predators, such as birds, snakes, or monitor lizards, are thought to be able to see UV light, suggesting the skinks might use this light to startle predators into breaking off their attack.

The study focused on the northern bluetongue skink (Tiliqua scincoides intermedia), the largest species of the group. The species sports good camouflage: broad brown bands across their backs to blend them into their surroundings. However, some of its main predators can still spot them, likely due to their ability to perceive UV light — so the team aimed to determine what tactics it uses to deter attackers.

First, they used a portable spectrophotometer to measure the color and intensity across different areas of the tongues of 13 skinks. This revealed that the blue tongues actually reflect UV light. Further data crunching in the lab later revealed that the tongues were almost twice as bright at the rear compared to the tip.

Mean spectra of different regions of the tongue. Associated illustration by Courtney Walcott of a Bluetongue skink performing a full-tongue display.
Image credits A. Badiane et al., 2018, Behavioral Ecology and Sociobiology.

Bloo!

The next part of the study was to identify how this bright tongue benefited the skinks. The team observed that skinks in the wild would open their mouths and stick their tongues out at would-be attackers. To find out more, the team simulated attacks on the lizards using models of their natural predators — the team used a snake, a bird, a goanna (monitor lizard), a fox — and a piece of wood as a control.

Skinks will rely on concealment for as long as they possibly can, the team reports. Should this fail, however, the lizards open their mouths widely at the last moment, revealing their UV-reflective tongues. One particularly amusing paragraph of the study suggests that the more intense attacks elicited a stronger tongue-response: the more risk the skinks felt exposed to, the more tongue they would poke at their enemies. I can relate to their fighting style.

Bluetongue display.

Northern Bluetongue skink performing a ‘full-tongue’ display in response to a simulated attack by a model predator. The face of a true warrior.
Image credits Peter Street / A. Badiane et al., 2018, Behavioral Ecology and Sociobiology.

“The lizards restrict the use of full-tongue displays to the final stages of a predation sequence when they are most at risk, and do so in concert with aggressive defensive behaviours that amplify the display, such as hissing or inflating their bodies,” explains lead author Arnaud Badiane.

“This type of display might be particularly effective against aerial predators, for which an interrupted attack would not be easily resumed due to loss of inertia.”

Finally, the team notes that tongue-displays were most often triggered by the fake bird and fox models, rather than by those of snakes or monitor lizards.

“The timing of their tongue display is crucial,” adds Badiane. “If performed too early, a display may break the lizard’s camouflage and attract unwanted attention by predators and increase predation risk. If performed too late, it may not deter predators.”

If you’re ever caught between a rock and a hard knuckle, stick your tongue out. It likely won’t be as effective as those of the skinks, but maybe you’ll confuse people enough to make your (brave and honorable) escape. Worth a shot.

The paper “Why blue tongue? A potential UV-based deimatic display in a lizard” has been published in the journal Behavioral Ecology and Sociobiology.

Prasinohaema prehensicauda is a green-blooded lizard with high concentrations of biliverdin, or a toxic green bile pigment, found in New Guinea. Credit: Chris Austin, LSU..

Lizards with lime-green blood might lead to cure for malaria and other diseases

In humans, blood is red due to the presence of hemoglobin molecules. However, animals may have red, blue, yellow, orange, violet, or even colorless blood — and if you’re a New Guinea skink, it can be green, too. According to a new study, the lizards’ blood is lime-green due to high levels of biliverdin, or green bile pigment. Although the pigment is toxic and causes jaundice, the lizards are surprisingly healthy even when the levels of green bile are 40 times higher than the lethal concentration in humans.

Prasinohaema prehensicauda is a green-blooded lizard with high concentrations of biliverdin, or a toxic green bile pigment, found in New Guinea. Credit: Chris Austin, LSU..

Prasinohaema prehensicauda is a green-blooded lizard with high concentrations of biliverdin, or a toxic green bile pigment, found in New Guinea. Credit: Chris Austin, LSU.

Researchers at Louisiana State University led by Professor Chris Austin went on numerous expeditions to the megadiverse island of New Guinea, documenting reptile and amphibian diversity. The goal of their new paper was to investigate the evolutionary history of green blood, which is present in several species of New Guinea lizards. Of the 51 species of skinks the researchers surveyed, six were green-blooded (Prasinohaema), two of which were new species to science.

“Fieldwork in Papua New Guinea is incredibly difficult due to the lack of a major road system so it means flying into the remote highlands in small planes landing on grass airstrips and then walking, sometimes for several days, to get to field sites,” Austin told ZME Science. “From earlier genetic results it seemed like there were multiple independent origins of green blood, but it was not until Zach Rodriquez (first author) generated and analyzed this huge genome-scale dataset that we had very strong evidence for the evolutionary history of this enigmatic physiological trait. His first results really were exciting!”

The investigation examined DNA samples from 27 green-blooded lizards and 92 closely related red-blooded lizards, showing that there are four separate lineages of green-blooded lizards, which all likely shared a common red-blooded ancestor. Because green blood emerged independently in various lizards, evolving four separate times, this suggests that the feature may have an adaptive value.

Although bile pigments are known to be toxic for many animals, some insects, fish, and frogs actually benefit from having the bile pigment in their blood, which acts as an antioxidant that neutralizes free radicals and prevents disease during in vitro fertilization. However, the function of bile pigment in the New Guinea lizards studied by the researchers is unknown.

“The physiological and/or ecological importance of biliverdin accumulation is unknown. This enigmatic trait may or may not be an adaptation. It is, however, plausible that small increases in biliverdin conferred some selective advantage, and that over evolutionary time even greater concentrations of biliverdin conferred an even greater advantage,” Austin said.

Green-blooded skinks may be important to medicine because a similar liver product called bilirubin is known to be toxic to human malaria parasites. Ongoing research will examine the potential effects of green blood pigment on malaria.

“Research on lizards from halfway around the world has implications for human health, thus our research shows how basic discovery science is important. Jaundice is a common problem for newborns, affecting 60% of full-term babies and 80% of premature babies. Importantly, our research will lay the foundation for an integrative way to think about bile pigments and jaundice and in doing so contribute to biomedicine and potentially improve human health down the road,” Austin said.

Findings appeared in the journal Science Advances.

The parietal and pineal foramina in the extinct monitor lizard are visible on the overlaid skull. Credit: Senckenberg Gesellschaft für Naturforschung / Andreas Lachmann.

Extinct monitor lizard used to have four eyes — and this is a pretty big deal

Scientists were stunned by the discovery of a four-eyed ancient monitor lizard that went extinct around 34 million years ago. This is the first example of such a creature among jawed vertebrates. To this day, the only animal that we know of that has four eyes is the jawless lamprey.

The parietal and pineal foramina in the extinct monitor lizard are visible on the overlaid skull. Credit: Senckenberg Gesellschaft für Naturforschung / Andreas Lachmann.

The parietal and pineal foramina in the extinct monitor lizard are visible on the overlaid skull. Credit: Senckenberg Gesellschaft für Naturforschung / Andreas Lachmann.

It used to be common among primitive lower vertebrates to have a ‘third eye’, a socket in the skull known as the pineal organ. As with a regular eye, the pineal eye is made up of a cornea, a lens, and a retina. However, unlike conventional eyes that can discern sharp features, a pineal eye is far more limiting, being only able to detect changes in brightness. ‘Now it’s dark; now it’s sunny,’ the third-eye tells the creature. Many existing reptiles such as monitor lizards, some iguanas, and the tuatara still have a pineal eye.

Of course, a pair of eyeballs can also inform a creature whether’s it’s dark or light outside, so what’s the point of having an awesome third eye? Research shows that in reptiles, the pineal eye acts more as a calendar, sensing when days are growing shorter and nights longer, informing the brain of seasonal fluctuations. The third eye may also aid in orientation. Our early pre-mammalian ancestors all had a third-eye, researchers think, but over the course of evolutionary history, it has since been discarded with the pineal organ being incorporated in the endocrine system.

A monitor lizard skull fossil fragment where both the parietal and pineal foramina are visible (highlighted in yellow). Credit: Yale Peabody Museum of Natural History.

A monitor lizard skull fossil fragment where both the parietal and pineal foramina are visible (highlighted in yellow). Credit: Yale Peabody Museum of Natural History.

There’s also a fourth eye-like photosensory structure known as the parapineal organ, and today lampreys form eyes from both structures. But when researchers at the Senckenberg Research Institute in Germany analyzed two specimens of the ancient monitor lizard Saniwa ensiden, which were collected during the 19th century in Wyoming, they were amazed to find that this ancient creature had both pineal and parapineal organs.

The CT scans showed that the individuals had spaces where a fourth eye could have been seated. This suggests that third eye of lizards evolved independently from those in other vertebrate groups. In fact, other researchers are studying third eyes in fossils to come up with a better timeline for the split between ‘cold’ and ‘warm’ blooded of our pre-mammalian ancestors. That’s because all reptiles that still have the pineal eye today are ‘cold-blooded’ while modern mammals, which are all ‘warm-blooded’, lack a pineal eye. Using such an approach, South African researchers at the University of the Witwatersrand estimated that this transition occurred 246 million years ago. 

Scientific reference: Current Biology, Smith et al.: “The Only Known Jawed Vertebrate with Four Eyes and the Bauplan of the Pineal Complex” http://www.cell.com/current-biology/fulltext/S0960-9822(18)30206-9 , DOI: 10.1016/j.cub.2018.02.021.

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.

 

Fossil Friday: the bug inside the lizard inside the snake

Forty-eight million years ago, a snake, a lizard, and an insect would unknowingly had a very, very bad day. But their Eocene tragedy would yield one of the most spectacular fossil finds of this year: the three animals fossilized together, one inside the other.

Yummy, yummy, get in my tummy. Forever!
Image credits Smith, K.T. & Scanferla A. / Palaeobio Palaeoenv (2016).

The fossil includes an unidentified insect ingested by a Geiseltaliellus maarius stem-basilisk (lizard,) which itself ended up as dinner for a juvenile Palaeopython fischeri snake. It was found in the Messel Pit, Germany, an area “renowned for the fidelity of preservation.” Today it’s a disused quarry but while these animals still lived, Messel was a volcanic lake with deep, toxic waters, and prone to belch out deadly clouds of carbon dioxide.

It’s unclear how the snake died, but no more than two days after eating the lizard it lay dead on the lake floor encased in fine sediment which would fossilize it, the lizard inside, and the insect inside both.

The fossil is the second of its kind ever found, and it preserves both the animals and a little piece of the day’s food chain. The other one was described in 2008 by a team led by the University of Vienna’s Jürgen Kriwet — it was a fossil of a shark that ate an amphibian with a spiny fish in its stomach.

It is, by all accounts, an astonishing find.

“It’s probably the kind of fossil that I will go the rest of my professional life without ever encountering again, such is the rarity of these things,” says Krister Smith, lead author of the paper describing the fossil.

“It was pure astonishment.”

The fossil will help define the range of Paleopython, which despite isn’t closely related to modern pythons.

“This fossil is amazing,” says Agustin Scafalera, co-author of the paper.

“We were lucky men to study this kind of specimen.”

Interpretive drawing of the fossil, overlaid on its photograph.
Image credits Smith, K.T. & Scanferla, A. / Palaeobio Palaeoenv (2016).

Maybe this is why my grandma told me not to swim after eating.

These ancient lizards trapped in amber will help researchers patch up the incomplete fossil records. Image: David Grimaldi

Oldest chameleon-like lizard found trapped in 100 million-years-old amber

The fossil record abounds with specimens of large animals, but seem to be discriminate against squishier, soft-bodied ones. That’s because fragile bones, let alone tissue, are more vulnerable to the elemental erosion, hence difficult to preserve. New specimens trapped in amber are always a treat for scientists. Usually, you can not only discern a complete skeleton, but also soft tissue like skin or even insect wings. Recently, a treasure trove of a dozen ancient lizards trapped in amber came to scientists’ attention. Everyone was impressed by the pristine preservation, but what particularly caught their eyes was a chameleon-like creature that’s 100 million years old. That’s 78 million years older than the previous record holder.

These ancient lizards trapped in amber will help researchers patch up the incomplete fossil records. Image: David Grimaldi

These ancient lizards trapped in amber will help researchers patch up the incomplete fossil records. Image: David Grimaldi

Initially discovered in a Burmese mine, the fossils remained in private collections until a recent donation to the American Museum of Natural History. Edward Stanley of the University of Florida and colleagues used a micro-CT scanner to image all the fossils trapped in the mid-Cretaceous amber. This allowed the researchers to build complete 3D models of each specimen without actually cutting open the amber.

“These fossils tell us a lot about the extraordinary, but previously unknown diversity of lizards in ancient tropical forests,” Stanley said.

“The fossil record is sparse because the delicate skin and fragile bones of small lizards do not usually preserve, especially in the tropics, which makes the new amber fossils an incredibly rare and unique window into a critical period of diversification.”

The preservation is mind-blowing. Complete specimens were found with all limbs intact, including claws, toepads, teeth, even perfectly intact coloured scales.

These small tropical lizards offer a glimpse into the mid-Cretaceous tropical life. The findings suggest that life in the tropical forest was just as diverse as it is today.

The ancient chameleon relative. Credit: David Grimaldi

The ancient chameleon relative. Credit: David Grimaldi

A dime-sized relative of the modern chameleon was among these animals. The juvenile had ballistic tongues, suggested by the presence of the same bone found in modern chameleons,  but had not yet developed the claw-like fused toes used today to cling to branches. Interestingly, one of the geckos trapped in the amber  already evolved its famous sticky pads which can adhere to virtually any surface.

A 3-D print of a gecko trapped in the same amber. Using CT scans, then printing the models allows researchers to investigate records in greater details -- all without risking ruining the delicate fossils themselves. Image: Florida Museum of Natural History

A 3-D print of a gecko trapped in the same amber. Using CT scans, then printing the models allows researchers to investigate records in greater details — all without risking ruining the delicate fossils themselves. Image: Florida Museum of Natural History

It is thought, based on genetic screenings, that chameleons split from an ancestor called  agamidae sometime around the mid-Cretaceous, but fossils were lacking to support this hypothesis. Stanley says that the newly found chameleon-like lizard challenges the notion that these animals originated from Africa.

According to the  SSC Chameleon Specialist Group (CSG), a third of the world’s chameleon species are threatened with extinction.

“These exquisitely preserved examples of past diversity show us why we should be protecting these areas where their modern relatives live today,” Stanley said.

“The tropics often act as a stable refuge where biodiversity tends to accumulate, while other places are more variable in terms of climate and species. However, the tropics are not impervious to human efforts to destroy them.”

Findings appeared in Science Advances.

The Jesus Lizard running on water

Jesus lizard ancestor skimmed the tropical waters of Wyoming, 48 million years ago

Paleontologists have discovered what looks like the earliest member of the Corytophanidae (also known as casquehead or helmeted lizards) judging from fossils collected in Wyoming. The ancient species is also the earliest ancestor of the modern basilisk, or better known as the Jesus Lizard because of its ability to skim the surface of water over short distances.

The Jesus Lizard running on water

The Jesus Lizard running on water. Image: National Geographic

The early Corytophanidae lived some 48 million years ago in the tropical rainforests of Wyoming. It’s hard to imagine tropics today given the deserts the litter the North American state, but we’re talking about the  Eocene Epoch – a period when greenhouse gas levels were very high in the atmosphere and temperatures were a lot hotter than today. In the Wyoming Bridger Basin where the ancient lizard was found, the temperature was up to 8 degrees Celsius on average higher.

The lizard was named Babibasiliscus alxi, where babi means “older male cousin” in Shoshone Native American – a tribute to the local heritage. Judging from the fossils, the lizard was likely two feet long, was active during the day and likely spent most of its time in trees. Like other casqueheads, the lizard has a ridge over its skull that likely made it look fiercer to its prey. Its teeth had three points suitable for eating snakes, lizards, fish, insects and plants. The larger cheekbones suggest it also hunted large prey.

“The generic name is meant to honor the Shoshone people who originally inhabited the areas in which the specimen was discovered,” Jack Conrad of the American Museum of Natural History explained.

Fossils, and digital reconstructions based on CT scans of the Babibasiliscus skull. Image: PLOS ONE

Fossils, and digital reconstructions based on CT scans of the Babibasiliscus skull. Image: PLOS ONE

Based on phylogenetic analysis Babibasiliscus is closely related to the modern genus Laemanctus, which includes the famous Jesus Lizard. The Jesus Lizard likes to live near water, that way, when it is frightened by an approaching predator it can get to the water and run across the surface. The lizards can run on water because they have a fringe of scales on their hind toes which makes little webs that can trap bubbles of air and water beneath their feet. This keeps them from sinking into the water if they run quickly enough across. When they do stop running they don’t mind taking a little swim. It’s not clear whether Babibasiliscus also skimmed water.

The Jesus Lizard and its genus relatives however are endemic only to the tropical areas of Central and South America. Babibasiliscus proves that the genus used to have a wider distribution going much farther North, according to the paper published in the journal PLOS ONE. This shows the cooling conditions following the Eocene period forced the lizards to migrate farther South, echoing current ecosystem crises.

“Given our current period of global climate fluctuation, looking to the fossil record offers an important opportunity to observe what is possible,” Conrad said, “and may give us an idea of what to expect from our dynamic Earth.”

Three species of tiny dragons discovered in South America

Some areas of South America are so special and magical… that you might even find a dragon – or actually, three of them! Tiny dragons, that is, but still, it’s something. Postdoc Omar Torres-Carvajal discovered three new species of dwarf dragons in the Andes of Peru and Ecuador.

The newly discovered rough-scaled woodlizard has a more traditional dragonesque look. (Torres-Carvajal et al.)

If you look at them, it’s easy to see where they got their name. Also called wood-lizards, these dragons have much in common with their mythological namesakes – except they’re tiny. When Omar started his post-doc, only a few dwarf dragons were known; they were thought to be one of the least diverse species of lizards in South America and in the world.

“During the last few years we doubled the number of known species of wood lizards, showing that the diversity of these conspicuous reptiles had been underestimated,” he said. “That more than half of the diversity of a group of large, dragon-looking reptiles from South America has been discovered in recent years should be heard by people in charge of conservation and funding agencies.”

A female specimen of the newly discovered Alto Tambo woodlizard. (Torres-Carvajal et al.)

Over the past years, he and his colleagues managed to discover seven new species in Ecuador and Peru – and now they found three more. There will also be likely more to follow.

“Woodlizards are fairly large and conspicuous, so it’s interesting that roughly half of the currently recognized species have been discovered in the last 10 years,” Kevin de Queiroz, Torres-Carvajal’s supervisor at the Smithsonian’s National Museum of Natural History, said in an email. “This illustrates how much we still have to learn about South American reptiles.”

Enyalioides altotambo, Enyalioides anisolepis and Enyalioides sophiarothschildae were discovered in an area often called the “biodiversity center of the world”. There are over 20,000 plant species found nowhere else in the world, and at least 1,500 species of vertebrates in the same situation – and there’s likely many other discoveries we’ve yet to make.

Enyalioides anisolepis, the rough-scaled woodlizard, seems to enjoy forest slopes, running around in the trees. E. anisolepis looks a lot like a mythological dragon, covered in threatening stud-like scales that point outwards. This species comes in several color variations, from black and bright green to brown to burnt orange. Enyalioides sophiarothschildae, the Rothschild’s woodlizard has a slender appearance with bright green spikes. Its most characteristic feature is its “immaculate white labials and chin”. While all these species have different features, researchers wanted to make sure they’re different species, so they conducted DNA analysis, which confirmed what biologists believed.

The Rothschild’s wood lizard, whose green spikes distinguish it from its peers. (Torres-Carvajal et al.)

It just makes you wonder how many other species still await to be discovered – and how many will be vanquished before we even have a chance to discover them.

Journal Reference: Omar Torres-Carvajal, Pablo J. Venegas, Kevin de Queiroz. Three new species of woodlizards (Hoplocercinae, Enyalioides) from northwestern South Americadoi: 10.3897/zookeys.494.8903

 

pinocchio-lizard

Rare long-nozed Pinocchio lizard discovered in Ecuador

pinocchio-lizard

Alejandro Arteaga / Tropical Herping

A rare sight to behold, the elusive Pinocchio lizard was finally spotted after a team of researchers and photographers set on a long quest to find it. Their efforts were rewarded as this is only the third time a specimen of this long-nosed lizard was ever reported in nearly the 60 years since its discovery.

Called the Pinocchio anole (type of lizard), the animal was first discovered in 1953. It was only seen again once  more than 50 years afterwards in 2005, leading many to believe the species was extinct.  Alejandro Arteaga, a co-founder of the educational and ecotourism company Tropical Herping, and colleagues were writing a book called “The Amphibians and Reptiles of Mindo,” a rural region a two-hour drive north of Quito, Ecuador’s capital, and didn’t want to settle with the extinction claim. They wanted a complete illustration for their book, so the team set out to find the lizard.

Lucas Bustamante / Tropical Herping

Lucas Bustamante / Tropical Herping

Night time is always the best time to go lizard hunting, since that’s when most animals are asleep and their pale colouring makes them inconspicuous while they go about their nocturnal ways.  After many days of stalking, one of Arteaga’s colleagues spotted and captured a Pinocchio anole clinging to a branch over a stream in January. The team then kept it overnight before photographing it in the morning in its natural habitat for their book.

Though definitely not extinct, the Pinocchio anole is by all means endangered, fact attested by its scarce sightings. In fact,  these lizards have been found in only four locations, mostly along a single stretch of road – one of the smallest ranges of any lizard in the world, Arteaga said.

Clearly its name was given thanks to the lizard’s uncanny resemblance to a certain lying wooden puppet. You might be wondering what’s its purpose? From a practical point of view, none – it’s just used to court ladies. Females don’t have long noses, and clearly this is a sexually selected trait – the male with the longest nose is the most attractive to females and thus has the most chances to pass on its genes. The peacock is the most famous co-example of such behaviour fond in nature, only instead of a long nose the peacocks employ marvelously coloured plumage.

Lizards have survival instincts even before they are born

Unborn lizards can erupt from their eggs days before they should if they recept vibrations that hint at a predator coming. The premature hatchlings literally begin their life by running as fast as they can.

egg

Talk about having an escape plan! The fact that lizards can have such spectacular survival reflexes even before they are born seems abolutely baffling to me – as it did to behavioral ecologist J. Sean Doody.

It is already well known that an array of factors can affect when eggs laid by all kinds of creatures finally hatch. Some fish hatch prematurely if a certain temperature is reached, as do some lizards in the case of a fungal infection. Negative chemical or physical signals have been noted to prompt a premature breakout for some, while others delay hatching in a bid to stay safe.

A professor at the the University of Tennessee, Knoxville, Doody and student Philip Paull of Monash University in Australia began studying a population of delicate skinks (Lampropholis delicata) in a park near Sydney. These lizards lay their white, aspirin sized eggs in crevices or rock cracks; it takes some 4-8 weeks for the eggs to hatch. However, in 2010, the two had a startling surprise when they were conducting measurements on the eggs.

“They started hatching in our hands, at just a touch—it shocked us,” Doody recalls. “It turned into a real mess, they were just hatching everywhere.”

Following this event, Doody started conducting a more scientifically controlled experiment. He placed lizards and their eggs in two separate laboratories, and subjected one of them to vibrations, while leaving the other one alone. He also conducted three field experiments, in which they poked and prodded eggs with a small stick, or squeezed them gently with their fingers to see if there is any effects caused by these predator-like stimuli. Together, all these experiments offer “compelling evidence” that embryonic skinks can detect and respond to predator-like signals, the authors write in the March 2013 issue of Copeia.

In the vibrated laboratory, hatchlings emerged out 3.4 days faster on average, while in the field, the hatching of disturbed eggs was “explosive” – as they note, with the newborns often breaking out and sprinting for short distances.

“It’s amazing,” Doody says. “It can be hard to see because it happens so quick.”

This does have a downside, as premature birth almost always has:

“[E]arly hatching skinks were significantly smaller and left behind larger residual yolks in their eggs than spontaneously hatching skinks,” the authors write, potentially reducing the chances of survival.

Still, it’s better to be smaller than eaten, if you ask me.

Via ScienceMag

Scientists discover vividly colored lizards in the Peruvian Amazon

There is still unbelievably much we have yet to discover from the Amazon. Now, researchers have uncovered two new species of woodlizards from Peru.

The blue woodlizard

The blue woodlizard

Woodlizards are little known species of reptiles, with only 10 species being described so far, all of which are found in Central or South America (9 in Peru). These new found species were found in Cordillera Azul National Park, one of the largest in Peru, and described in ZooKeys.

Male and female (duller colored) of Bin Zayed's woodlizard (Enyalioides azulae).

Male and female (duller colored) of Bin Zayed’s woodlizard (Enyalioides azulae).

“These species were discovered in recent expeditions to poorly explored areas on both sides of the Andes in Ecuador and Peru, suggesting that more species might be awaiting discovery in other unexplored areas close to the Andes,” the researchers write.

Blue woodlizard.

Blue woodlizard.

The species were named Enyalioides azulae, or the blue woodlizard, and Enyalioides binzayedi, or Bin Zayed’s woodlizard after Sheikh Mohamed bin Zayed Al Nahyan, the Crown Prince of Abu Dhabi and UAE – who funded the expedition.

lizard 4

Bin Zayed’s woodlizard.

“Thanks to these discoveries, Peru becomes the country holding the greatest diversity of woodlizards. Cordillera Azul National Park is a genuine treasure for Peru and it must be treated as a precious future source of biodiversity exploration and preservation!” said lead author Pablo Venegas from the Centro de ornitología y Biodiversidad (CORBIDI) in Lima, Perú.

There is, at the moment no indication of whether woodlizards are threatened, as no such study has been conducted. However, this is once again a clear indication about the wonderful biodiversity that thrives in the Amazon and which we are endangering more every day.

lizard 5

Source

Lizards facing mass extinction due to global warming

Within the next 50 years, numerous lizard species could become extinct due to global warming, a research by Daniel Pincheira-Donoso, from the School of Life Sciences at the University of Lincoln (UK) concludes.

lizard

Not all lizards lay eggs – some are viviparous, and develop their embryos inside the mother’s body as opposed to an egg. Viviparous lizards are most threatened by changing weather patterns, and in fact, this feat once thought to be the result of successful adaptation could be what brings their demise in the context of global warming.

Particularly in cold climates, it’s harder to lay eggs, so lizards living in such conditions have slowly adapted to viviparity. However, once this process begins, it is irreversible and the species remain restricted to such cold climates, unable to adapt to warmer areas. By analysing this evolutionary transition in the lizards’ reproductive modes and projecting the future impact of climate change, researchers discovered that increasing temperatures in their habitats would basically wipe them out, with no chance of adaptation.

“Lizards’ reproduction is largely linked to climatic temperatures and viviparous species are usually found in cold environments. When reptiles initially moved to colder areas they needed to evolve emergency measures to succeed in these harsh places, and we believe viviparity is one of these key measures. However, this transition is mostly one-directional and unlikely to be reversed. Rapid changes in the environment’s temperature would demand rapid re-adaptations to secure the species’ survival. Through the research we found that over the next 50 years nearly half of the area where these species occur may disappear, causing multiple extinctions due to climate change.”

The conclusion is that while this adaptation allowed them to thrive in cold areas, and was therefore a key trait for evolutionary success, it will now probably lead to a massive extinction.

“These lizards are one of the most diverse groups of animals, and are able to adapt to remarkably diverse conditions. Unfortunately, a reduction in cold environments will reduce their areas of existence, which means that their successful evolutionary history may turn into a double-edged sword of adaptation. Their extinctions would be an atrocious loss to biodiversity.”

Article and photo via University of Lincoln.