New Smaug lizard species discovery in Africa


This February 2019 video from South Africa is called SAVING OUR “DRAGONS”. It is about sungazer lizards, the biggest species in the Smaug genus.

From the Florida Museum of Natural History in the USA:

Here be dragons: Analysis reveals new species in ‘Smaug’ lizard group

March 25, 2020

Smaug, the deadly dragon in J.R.R Tolkien‘s “The Hobbit“, has a few living relatives. With dense, alligator-like armor, these small, real-life dragon lizards are rock-crevice recluses mostly confined to mountaintops in southern Africa.

Now, herpetologists Michael Bates, a curator at South Africa’s National Museum in Bloemfontein, and Edward Stanley of the Florida Museum of Natural History have discovered a ninth species of dragon lizard in the genus Smaug, previously mistaken for a similar-looking species, S. barbertonensis.

The new species, a heavily plated dark brown lizard with pale yellow bands, has been named Smaug swazicus, or the Swazi dragon lizard, in honor of the country of Eswatini, where most of the species’ range is located. Up to 13 inches from snout to tail tip, S. swazicus is an unusually big lizard for the region.

“In terms of bulk and actual recorded total length, Smaug swazicus may be the largest southern African lizard species described since the western giant plated lizard, Matobosaurus maltzahni, 82 years ago,” Bates said.

While species in the Smaug genus, also known as girdled lizards, may have scaled-down versions of their fearsome namesake’s shield-like scales and sword-like teeth, they have gentle dispositions, Stanley said.

“They’re just little tanks,” said Stanley, who is also the director of the Florida Museum’s Digital Discovery and Dissemination Laboratory. “They hide in rock cracks and put a lot of their energy and effort into simply being spiky and inedible, so they don’t have to put up a big fight.”

Stanley led a group of scientists that named the Smaug genus in 2011, and he has been instrumental in parsing out its species. “Smaug”, he explained, comes from the German word “smugan,” which means “to squeeze through a hole.” These lizards are also found near South Africa’s Drakensberg Mountains, Afrikaans for “dragon mountains.”

While Africa has an enormous diversity of lizards, girdled lizards are the only family exclusive to mainland Africa and, because of their crevice-dwelling lifestyle, are often restricted to specific habitats. As a result, Stanley said more stringent conservation strategies may be needed for certain Smaug species.

“S. barbertonensis already had a relatively restricted range, but that’s obviously before it was split in half when S. swazicus was discovered,” Stanley said. “So, although barbertonensis wasn’t of concern before, it now has a range of only around 200 square miles,” an area less than the size of Chicago.

Tethered to high-elevation boulder-filled habitats, dragon lizards could already be feeling the effects of a warming climate, Stanley said. Securing rock crevices in which to hide could become challenging as dragon lizards creep to higher elevations in search of lower temperatures.

“These creatures are brilliantly evolved for their environment. If things aren’t done to protect them, we could lose 20 million years of evolution in 50 years,” he said. “The important thing is that you need to characterize and identify animals before you can protect them. You need to know what you have before you can make a plan to protect it.”

But finding lizards in southern Africa can be daunting: Stanley and his fellow researchers had to dodge everything from mambas to undetonated explosives. When team members expanded their search to well-shaded boulders on a military base, they were accused of being gold prospectors, thieves and pet trade dealers.

“We had to spend all morning explaining, ‘No, we’re not here for any of that — we’re really here just to try and find some lizards on your army base,'” Stanley said. “And in fact, because the range was so unpopulated, the lizards we found there were quite friendly. It was a weird experience having spent such a long time looking for them and then going into this sort of garden where they’d run on your lap and jump into your arms.”

Stanley’s next run-in with the new species wasn’t deep in the South African escarpment. He said he recognized the species from his time at the American Museum of Natural History, where there was a jar of unidentified pet trade specimens from the early 1980s in the herpetology collection.

“That’s the nice thing about museums, isn’t it? It’s not like these animals are sitting underground, never before seen. A lot of times they’re just hiding in plain sight,” he said.

To differentiate similar-looking species, Stanley and Bates relied on traditional approaches based on physical features, CT scanning and DNA analysis, a process he compared to sorting candy.

“Say you have different kinds of candies that you need to sort by type,” Stanley said. “You start by visually sorting all your M&M’s into one pile and your Mike and Ike’s in another.”

Then comes the DNA analysis — in other words, the taste test.

“So, you sample your candies, and you find that there are a proportion of M&M’s you’ve sorted that are actually Skittles, and then you notice that instead of an ‘M,’ they actually have a tiny ‘S’ on them,” Stanley said. “You can now pull these out and say, ‘Oh, I actually have three candies.'”

The new species of dragon lizard can be compared to the Skittles, Stanley said — similar in appearance to S. barbertonensis, but with slight genetic differences that show it’s more closely related to another species of dragon lizard, S. warreni. The analysis also allowed Stanley and Bates to parse minor physical differences that other researchers originally attributed to individual variation and helped explain why Bates’s previous examination of museum specimens had revealed three distinct color patterns in dragon lizards.

Stanley said he can’t rule out the possibility that more species in the group await discovery.

“Even now, in this well-worked group in these very populated countries of South Africa and Eswatini, that have had a lot of herpetologists working for hundreds of years, there are still some cool discoveries to be made,” he said. “That’s the biggest part of the story for me, is that there are some awesome animals out there just undescribed.”

Blue iguanas fight against extinction


This 14 March 2020 video from the Cayman Islands says about itself:

Blue Iguana Fights Extinction and Wins!

On this episode of On Location, Mark and the crew are in one of the most remote parts of Grand Cayman Island to meet a lizard that was brought back from the brink of extinction! The Blue Iguana is one of the most beautiful and rarest iguanas on the planet. Meet Peter, a true ambassador for his species!

Get ready, you’re about to see a blue iguana that fought extinction and WON!

Puerto Rican urban lizards evolution


This 2013 video is called Lizards at the Caribe Hilton in San Juan Puerto Rico.

From Washington University in St. Louis in the USA:

Hot time in the city: Urban lizards evolve heat tolerance

March 10, 2020

Faced with a gritty landscape of metal fences, concrete walls and asphalt pavement, city lizards in Puerto Rico rapidly and repeatedly evolved better tolerance for heat than their forest counterparts, according to new research from Washington University in St. Louis and the University of California, Los Angeles.

Studies that delve into how animals adapt in urban environments are still relatively rare. But anoles are becoming a model system for urban evolutionary research.

“Urban lizards are exposed to higher temperatures, consistent with the urban heat island effect,” said biologist Kristin Winchell, postdoctoral research associate in the Losos laboratory in Arts & Sciences. “We found that they are able to maintain their function at temperatures of about 0.82 degrees C (or 1.47 F) higher on average across all populations.”

In one population in this study, urban lizards were able to go about their business in temperatures above 40 C (104 F). That’s a lot of heat for a tiny animal — one that measures about 5 centimeters long, not including its tail.

“Better heat tolerance can make all the difference in an urban habitat,” Winchell said. “Whether it’s being able to stay active during longer parts of the day or being able to occupy perches that reach higher temperatures, it expands their niche space.”

This adaptive thermal response is even more interesting because only those lizards that grow up in the city seem to be able to tap into it — an example of natural selection favoring trait ‘plasticity,’ researchers said. The study is published March 9 in the journal Nature Ecology & Evolution.

A hidden superpower

In previous work, Winchell showed that city lizards have evolved longer limbs and larger toepads with specialized scales. Both of these traits allow them to more effectively and quickly traverse urban habitats, allowing them to climb up smooth, painted walls.

Compared with these adaptations, thermal tolerance is a relatively complex trait. It affects multiple body systems and involves potentially hundreds of genes. And cold-blooded animals like these lizards also have the option to behaviorally regulate temperature — for example, by shuttling in and out of sun, or by changing the time of day when they hunt or look for mates.

Winchell’s partner for this effort, Shane Campbell-Staton, assistant professor at UCLA, is an expert at sussing out genomic aspects of thermal adaptation.

“A big part of this story is that the target of selection in urban heat islands is plasticity, the ability of an individual to respond adaptively to its environment,” Campbell-Staton said. “Individuals that are high responders — that is, those that can become more heat tolerant when raised in cities — are favored by natural selection. The major difference is that the adaptation only appears when an individual is born and raised in a city environment.

For example, when Winchell’s previous work showed that lizards with long limbs do better in cities, those individuals would have longer limbs no matter where they are raised.

“In contrast, differences in heat tolerance are hidden in a forest habitat and only show themselves when the proper genes are exposed to warm temperatures,” Campbell-Staton said. “It’s kind of like a hidden superpower that only presents itself in the right environment. We are only just beginning to understand how natural selection works on this type of trait to influence the process of evolution.”

Comparing city lizards to forest lizards

The ability to withstand more heat anytime, anyplace, is potentially a game-changer for Anolis cristatellus, the most abundant and visible species in urban environments of the 10 kinds of lizards that are found across Puerto Rico.

Winchell and her team studied 150 lizards from four municipalities across the island, including the capital San Juan. Each of these locations was part of a paired site: with one lizard collection area in the city, and the other in a nearby forest. The researchers also brought back some of the lizards to a laboratory setting at the University of Massachusetts Boston, where Winchell was a graduate student at the time.

The scientists relied on an established lizard research protocol that tests thermal tolerance as a measure of a lizard’s ability to right itself after being placed gently on its back. The researchers raised the temperature by small increments, and the trial ended when a lizard took too long to right itself. After the tests, a cool water bath helped bring the lizards comfortably back down to normal temperatures.

Separately, the researchers also took tissue samples from lizards exposed to cold, ambient and warm temperatures. Genetic tests revealed different patterns of gene expression in the tissues from city and forest lizards exposed to different temperatures.

Even more interesting, the researchers discovered a single gene variant that differed consistently between the city and forest populations — one that was associated with differences in thermal tolerance. The researchers believe that this indicates natural selection is selecting for the ability to respond to higher temperatures when needed, what they refer to as a ‘high-plasticity genotype.’

Rapid and repeated changes

“One of the unique and exciting things for me about this study is that we’re able to simultaneously address this question about the repeatability of evolution at several different levels of biological organization,” Campbell-Staton said.

“Starting at the whole organism level, we clearly see that urban lizards are able to maintain functioning at significantly higher temperatures than their forest counterparts.

“Then, when we look at all the genes that are being differentially expressed, we see pretty high repeatability in how those large suites of genes are changing as well,” he said. “But if you zoom in even further, we found not only a single gene, but what seems to be a single polymorphism that is repeatedly under selection in these urban heat islands as well, which is fascinating.”

By studying how animals adapt to different habitats, like life in the city, researchers have a unique opportunity to investigate traits that are environmentally dependent but influenced by an animal’s genetic makeup.

That dynamic is part of why Winchell says she is partial to A. cristatellus, which is abundant in urban areas not only in Puerto Rico, but outside of their native range in the southern United States and other parts of the Caribbean.

“I like to say they are urbanophilic, or urban-loving species,” Winchell said. “There are other terms that people use, like urban tolerant or urban-adapting. But I think urbanophilic captures it best. They’re exploiting novel niche space that isn’t present in the forest environment. But they’re not reliant on humans. If humans went away, they would still do fine.”

Caribbean lizards evolution, new research


This 8 March 2020 video says about itself:

How Lizards are Turning Our Knowledge of Evolution Upside Down

Lizard biologists in the Caribbean have observed a fascinating phenomenon: different lizard species across different islands appear to share specific physical traits. But how, if they’ve never been in contact?

Fossil Miocene lizard discovery in Dominican amber


This 2017 video is called Dominican Amber Fossil Anolis Lizard Inclusion.

From the University of Bonn in Germany:

Rare lizard fossil preserved in amber

February 27, 2020

The tiny forefoot of a lizard of the genus Anolis was trapped in amber about 15 to 20 million years ago. Every detail of this rare fossil is visible under the microscope. But the seemingly very good condition is deceptive: The bone is largely decomposed and chemically transformed, very little of the original structure remains. The results, which are now presented in the journal PLOS ONE, provide important clues as to what exactly happens during fossilization.

How do fossils stay preserved for millions of years? Rapid embedding is an important prerequisite for protecting the organisms from access by scavengers, for example. Decomposition by microorganisms can for instance be prevented by extreme aridity. In addition, the original substance is gradually replaced by minerals. The pressure from the sediment on top of the fossil ensures that the fossil is solidified. “That’s the theory,” says Jonas Barthel, a doctoral student at the Institute for Geosciences at the University of Bonn. “How exactly fossilization proceeds is currently the subject of intensive scientific investigation.”

Amber is considered an excellent preservative. Small animals can be enclosed in a drop of tree resin that hardens over time. A team of geoscientists from the University of Bonn has now examined an unusual find from the Dominican Republic: The tiny forefoot of a lizard of the genus Anolis is enclosed in a piece of amber only about two cubic centimeters in size. Anolis species still exist today.

Vertebrate inclusions in amber are very rare

The Stuttgart State Museum of Natural History has entrusted the exhibit to the paleontologists of the University of Bonn for examination. “Vertebrate inclusions in amber are very rare, the majority are insect fossils,” says Barthel. The scientists used the opportunity to investigate the fossilization of the seemingly very well preserved vertebrate fragment. Since 2018 there is a joint research project of the University of Bonn with the German Research Foundation, which contributes to the understanding of fossilization using experimental and analytical approaches. The present study was also conducted within the framework of this project.

The researchers had thin sections prepared for microscopy at the Institute for Evolutionary Biology at the University of Bonn. The claws and toes are very clearly visible in the honey-brown amber mass, almost as if the tree resin had only recently dripped onto them — yet the tiny foot is about 15 to 20 million years old.

Scans in the micro-computer tomograph of the Institute for Geosciences revealed that the forefoot was broken in two places. One of the fractures is surrounded by a slight swelling. “This is an indication that the lizard had perhaps been injured by a predator,” says Barthel. The other fracture happened after the fossil was embedded — exactly at the place where a small crack runs through the amber.

Amber did not protect from environmental influences

The analysis of a thin section of bone tissue using Raman spectroscopy revealed the state of the bone tissue. The mineral hydroxyapatite in the bone had been transformed into fluoroapatite by the penetration of fluorine. Barthel: “This is surprising, because we assumed that the surrounding amber largely protects the fossil from environmental influences.” However, the small crack may have encouraged chemical transformation by allowing mineral-rich solutions to find their way in. In addition, Raman spectroscopy shows that collagen, the bone’s elastic component, had largely degraded. Despite the seemingly very good state of preservation, there was actually very little left of the original tissue structure.

“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.

Acids in tree resin attack bone

Amber is normally considered an ideal preservative: Due to the tree resin, we have important insights into the insect world of millions of years. But in the lizard’s bone tissue, the resin might even have accelerated the degradation processes: Acids in the tree secretion have probably attacked the apatite in the bone — similar to tooth decay.

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Endangered lizard conservation in California, USA


This 2014 video from the USA is called Blunt-nosed leopard lizard, endangered species project.

From the University of California – Davis in the USA:

Detection dogs and DNA on the trail of endangered lizards

Noninvasive scat sampling could strengthen reptile conservation

October 30, 2019

Detection dogs trained to sniff out the scat of an endangered lizard in California’s San Joaquin Valley, combined with genetic species identification, could represent a new noninvasive sampling technique for lizard conservation worldwide. That is according to a study published today from the University of California, Davis, in partnership with the nonprofit Working Dogs for Conservation, U.S. Geological Survey and the U.S. Bureau of Land Management.

Scientists have used trained conservation dogs to locate scat and collect DNA samples for everything from bears and foxes to gorillas and whales. But the technique had not been used for reptiles until this study, for which scientists developed a novel approach to identify the presence of the blunt-nosed leopard lizard in the Panoche Hills Recreation Area and Carrizo Plain National Monument, both managed by BLM.

They developed new methods to recover DNA from feces and genetically identify lizard species in the same area. The study, published in the Journal of Wildlife Management, is a proof of concept for a host of reptiles.

“So many reptilian species have been hit so hard,” said lead author Mark Statham, an associate researcher with the Mammalian Ecology and Conservation Unit of the UC Davis School of Veterinary Medicine. “A large proportion of them are endangered or threatened. This is a really valuable way for people to be able to survey them.”

NO DIRECT CONTACT NEEDED

Current methods for surveying lizard species typically rely on live capture or visual surveys. Scat sampling allows biologists to study elusive, rare or dangerous animals without the need for direct contact. In addition to informing about the presence, habitat and genetics of an animal, scat can also be analyzed to inform researchers about diet, hormones, parasites and other health factors.

Using the new method, the authors genetically identified specific species for 78 percent of the 327 samples collected by dog-handler teams across four years. Most (82 percent) of those identified were confirmed as being from blunt-nosed leopard lizards.

To meet regulatory monitoring requirements, more research is needed to assess the viability of using detection dogs to recover usable DNA at larger scales. But the research highlights the broad potential this method holds for surveying and monitoring reptiles.

Study co-authors include Deborah A. Woollett, Alice Whitelaw and Ngaio L. Richards of Working Dogs for Conservation; Susan Fresquez, Jerene Pfeiffer and Benjamin Sacks from UC Davis School of Veterinary Medicine; Jonathan Richmond from the U.S. Geological Survey; and Michael F. Westphal of the U.S. Bureau of Land Management.

Funding was provided by the Bureau of Land Management.