Argentinian, American and Canadian paleontologists have just announced a new species of giant carnivorous dinosaur – Meraxes gigas – first discovered in 2012 in Neuquén, a province in Argentina’s Patagonia region. The first comprehensive scientific study of this species has just been published in Current biologya journal that publishes original research in all areas of biology.

The species is a carcharondontosaurid theropod dinosaur, the largest predator of the Cretaceous period (90 to 100 million years ago). Like all theropods, they were bipeds with short arms and light bones. Members of this particular family of dinosaurs were the longest of theropods, measuring about 40 feet (12-13 meters) from snout to tail. One of its most distinctive features was its sharply serrated, curved teeth that resembled four-inch pruning saws (Carcharodontosaurus means shark-toothed lizard in Greek). Weighing more than four tons, “the great dinosaur eater”, as the National University of Río Negro press release dubbed it, was once one of the largest carnivorous lizards in South America.

Palaeontologist Juan Ignacio Canale, a researcher at the Argentine National Council for Scientific and Technical Research (CONICET) and the National University of Río Negro, is the main author of the Current biology article. In a Winter Patagonia video interview, Canale said it reminded her of a particular dragon. “I found this name because I like A song of ice and fire, the epic fantasy novel series that inspired the hit game of thrones TV series. “I love the names George RR Martin chose for his dragons, and this one [Meraxes] fit perfectly as both are very large reptiles with giant skulls. We also needed a new name to distinguish Meraxes of two other giant carcharodontosaurs found in Neuquén: Giganotosaurus carolinii – the “villain” of the last jurassic world movie – and Mapusaurus. It is the third of its kind, like the three dragons of A song of ice and fire“, said Canale.

Ten years of research funded by the municipality of El Chocón (the fossil-rich town of Neuquén), National geographic, and the Field Museum in Chicago (USA) preceded this dramatic announcement. Unearthing the dinosaur was quick by comparison. On the first day of fieldwork, they spotted an exposed spinal vertebra. “We started digging and more and more bones appeared. We were shocked,” Canale said. “We found a skull without a mandible, but with an intact maxilla and some teeth.” They were actually nascent teeth because unlike humans, dinosaurs and crocodiles produce several generations of teeth throughout their lives. The Neuquen Meraxes was 45 years old when it perished, making it one of the oldest carnivorous dinosaurs to have been discovered.

Almost all of the arm and leg bones were found intact, “which is very unusual because in general not much remains of the legs and arms of the largest carcharodontosaurs discovered from the mid to late Cretaceous,” said Channel. This allowed the research team to identify a new distinguishing feature of this species – a powerful claw on the inner toe that is much larger and sharper than the other two.

The hips are also distinctive. The spines on the dinosaur’s back project upward above the waist and resemble the hump on the Concavenator, discovered in 2015 in Cuenca (Spain). In another nod to the literary inspiration of the dinosaur’s name, the press release describes this part of the dinosaur as “Queen Rhaenys Targaryen’s saddle,” after the dragon ridden by the fictional queen.

The skull is another excellent specimen. As well as being huge, it is the most complete example found to date and features complex bones with protrusions, ridges and grooves. It has provided researchers with valuable information not only about Meraxes, but on all species of the family, including the famous gigantosaurus.

“It provided a lot of information about their anatomy,” Canale said. “We observed that the arms were very short, something we previously suspected, but can now say for sure since we have actual measurements.” The analysis concluded that, like other known groups of carnivores such as Tyrannosaurus and Abelisaurus, the arms shortened over time until they were only 40% the size of the femur. . Then they stopped shrinking and no one knows why. “The question is why did they reach this limit? Why didn’t the arms keep shrinking? The proportion of arms to femur is similar in all of these species,” Canale said. Like many scientific endeavours, some answers simply raise more questions.

The research team tested various hypotheses. “We observed that the pectoral girdle, where the arm, shoulder blade and other bones are inserted, is not small where the arm inserts. It is a very large and well-developed bone that encapsulates a much of the musculature that extends to the extremities. Since this musculature has to fit in somewhere, this may be the reason why the arms did not shrink further. All the musculature that came from the scapula had to be inserted somewhere. The usefulness of such short limbs is still controversial. Some believe that they were used for support during copulation, to tear prey or simply to avoid hitting the ground. But the size arms doesn’t seem so important when you have a huge skull. Meraxes gigas was just over four feet (1.27 meters) long. Other Carcharodontosaurus also had big heads, like the tyrannosaurus rex (4.6 feet or 1.40 meters) and the Giganotosaurus carolinii (5.3 feet or 1.63 meters). “What other carnivorous hunters did with their arms, these dinosaurs could do with their heads – grabbing and handling prey, pinning it down and killing it,” Canale said. Therefore, the arms would not have been very useful for eating, especially when trying to devour other giants like the argentinosaurus, one of the largest herbivores in the history of the planet. “It is certainly no coincidence that carnivores and large herbivores co-existed. There is probably a relationship with the food chain. It’s like an arms race: prey grows bigger as a defense mechanism, and their predators also grow bigger to be able to hunt them,” said the paleontologist.

By looking at other co-existing species, scientists can theorize about the evolutionary end of carcharodontosaurus family of dinosaurs. Specimens of two other species – Mapusaurus and Taurovenator – from the same geological period (93-96 million years ago) were discovered. “This leads us to postulate that before disappearing, they reached a maximum level of diversification. This is a group that diversified a lot just before its extinction. This is when they became extinct and were no longer the top land predators of their time in South America. Later, they will be succeeded by abelisaurids and megaraptors, but that’s another story.

The team of scientists includes Sebastián Apesteguía, Pablo Gallina, Alejandro Haluza and Federico Gianechini from Argentina; Jonathan Mitchell, Nathan Smith, Akiko Shinya and Peter Macovicky from the United States; and Thomas Cullen from Canada. The team plans to continue their research using more sophisticated techniques such as CT scans and detailed reconstructions, as they seek more answers about the bones, muscles and general anatomy of the “Ice and Fire” dragon.

Some people are recognized when a grandchild bears their name or a scholarship is created in their honor.

The legacy of biology professor Greg Adler at the University of Wisconsin at Oshkosh is solidified this week as a new species of possum he collected a decade ago is described in a publication by the American Museum of natural History.

And here is the kicker …

The new species featured in the December 8 issue of American Museum Novitates is called Marmosa Adleri, which is Latin for Adler’s mouse opossum.

Robert Voss, Curator of the Department of Mammalogy at the American Museum of Natural History, is the lead author of the article which describes Marmosa alderi as among the smallest measured of the sub-genre Micourea. The new species has a very long tail that is about 160% of its head and body length on average.

“The discovery of this new opossum species is very unusual as I collected it from what may be the most studied area of ​​rainforest in the world,” Adler said. “Many expeditions collected thousands of specimens there throughout the 20th century and never found this species. It is amazing that he has escaped discovery for so long.

The discovery is a culmination of Adler’s nearly 30-year career studying mammals, including rodents and opossums, in tropical rainforests around the world.

“In 2001, I captured a lot of mouse opossums, which were common and widespread in the wooded parts of central Panama. I captured an individual in a national park that had a slightly different color on the belly, and I wasn’t sure if it was just a color variation of a common species or a different species ” , Adler explained.

At the time, he had no idea that it was an unknown species.

Greg Adler with a thorny rat in central Panama, just a few miles from where he captured the new opossum species.

“In my fieldwork around the world, I had always hoped to discover a new species. Of the places I had worked, I thought my best chances were in Vietnam or French Guiana, and I thought the least likely would be central Panama because that area was much more thoroughly sampled, ”he said. -he declares.

Adler added that he was “both flattered and honored” to have a new species named after him.

“It’s kind of a reward for decades of hard work under harsh conditions in remote rainforests,” he said.

In the American Museum Novitates article, Voss elaborated on Adler’s impact:

“Adler’s numerous publications include important contributions to knowledge of seed dispersal, habitat use, community ecology, and the demography of small Neotropical mammals based on decades of research. trapping studies in Panama and northern South America. “

Back in class at UW Oshkosh, Adler teaches a number of courses, including ecology and evolution, a requirement for biology majors.

“I haven’t told any of my students about this discovery, but I probably will at some point as I stress the importance of being aware and observant whenever they are outside. . “

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Florida restricts the possession and private breeding of certain exotic animals, including Burmese pythons, green iguanas and tegu lizards, citing concerns about invasive species invading the state. This decision is met with strong opposition from enthusiasts and reptile dealers.

“The environment trumps livelihoods over it, unfortunately,” said Rodney Barreto, chairman of the Florida Fish and Wildlife Conservation Commission. He and his colleagues voted unanimously on Thursday to support the policies. “It’s not an easy decision, but it’s a decision we have to make.”

The rules prohibit people from owning as pets or raising for sale any animals, including: Nile monitor lizard, Burmese python, North African python, reticulated python, tegu lizards, iguanas greens, the southern African python, the amethystine python or the brush python. Some, like the iguana and the Burmese python, are well established and breed in Florida. Others, like reticulated pythons which can grow to over 20 feet, are not, but state wildlife regulators say they want to avoid problems before they arise. They worry about escaped and released animals that create or increase wild populations.

“These animals do a lot of damage,” said Commissioner Robert Spottswood.

People who have iguanas and tegus will not need to return or kill them immediately. Owners can keep currently legal pets until they die. Some breeders will be allowed to import and own species in the future, under specific conditions, for limited uses such as exhibitions or research. They will also be able to capture wild tegus and iguanas for sale or send them out of state, according to a state submission, and the ban on breeding these lizards for commercial sales will not begin until 2024.

Critics tried Thursday to dissuade the commissioners, describing their personal attachment to reptiles. People misunderstand snakes and lizards, they said, comparing their chosen pets to dogs and cats. Several callers logged into the meeting from out of state.

“People who own reptiles have a mental and emotional connection with them,” said Nicole Tisdale, who said she has reptiles living in Maryland and reconsidered moving to Florida due to the new rules. “They are part of our family, they are part of our being.”

Ahead of the vote, Melissa Tucker, who heads the commission’s Habitat and Species Conservation Division, described the problems invasive reptiles are causing in Florida. She said the warm climate is beneficial for animals that don’t belong here and that displace or kill native wildlife.

Tegus, for example, are a troublesome lizard in several areas, including Hillsborough County, and are known to eat alligator eggs and compete with gopher turtles for burrows. Green iguanas undermine roads by digging in South Florida and devour homeowners’ plants.

The reptile trade can be worth up to $ 200 million a year in Florida, according to Tucker, but the species affected by the rule are part of a market that includes thousands of animals. She said regulators are aware of about 120 licensees statewide who have inventories of tegus or iguanas and a few dozen dealers who sell reptiles such as the listed snakes.

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The Fish and Wildlife Conservation Commission spends more than $ 8 million a year to manage invasive species, Tucker said, including nearly $ 1 million for the Argentine black-and-white tegu.

Critics questioned the accuracy of the agency’s financial assessments and accused Tucker of “sensationalizing.” Cutting back on wildlife trade, especially key lizards such as tegus and iguanas, they said, will affect related operations, including food suppliers and shipping companies.

Miranda Hill, owner of a reptile business in Daytona Beach, said last year that she bought more than $ 12,000 of exotic animals, paying $ 50 or $ 100 in shipping costs with each ordered.

“No one is saying these wild animals are not a problem,” she said.

Several callers said they would accept tighter regulations or tighter licensing policies, but that an outright ban was government abuse. The new rule, they said, does nothing to reduce current wildlife populations while isolating cautious breeders and hobbyists who could help the state capture problem snakes and lizards.

“You are creating a rule that creates criminals out of law-abiding citizens,” said Anthony Green, owner of Anthony’s Exotic Rescues in Tampa. Some opponents have predicted an increase in black market transactions.

Chris Cannarozzi, who said he runs a reticulated python breeding operation in Gainesville, described how the new rules could threaten a career that has taken decades to build.

“If this ban passes, everything I worked for will be lost,” he said. “Not every invasive animal contemplated will turn into this Burmese python situation.”

Proponents countered that it made little sense for Florida to spend money catching and killing animals that people are then allowed to keep and buy as pets.

Take the iguanas, said Kate MacFall of the Humane Society: “If the owners regularly tried to kill these lizards, sometimes without success, their neighbor can buy one for a small fee.

Pedro Ramos, director of the Everglades and Dry Tortugas National Parks, said billions of dollars in taxes are being spent to restore habitats in South Florida, but that investment will be wasted if Burmese pythons continue to devastate deer, raccoons and other native wildlife.

“We’re not going to do it for a bunch of weeds and animals that don’t belong here to begin with,” Ramos said. “This alien problem may well be – and I don’t think I’m exaggerating in saying – the problem of our time.”