Mostrando postagens com marcador maior pterossauro. Mostrar todas as postagens
Mostrando postagens com marcador maior pterossauro. Mostrar todas as postagens

sexta-feira, 20 de setembro de 2019

‘Frozen dragon of the north wind’ flew over North America 77 million years ago, scientists say


An artist's illustration of the Cryodrakon boreas, a new species of pterosaur that was identified in Alberta, Canada. (David Maas)
 
A new species of pterosaur, a flying reptile, has been identified in the vast, dry terrain of Canada’s badlands. On Tuesday, it was anointed as “Cryodrakon boreas,” Greek for “Frozen dragon of the north wind.” 

The discovery may sound like something out of Westeros (who can forget Jon Snow, beleaguered king in the north, riding Rhaegal over the icy wilderness?) but “Game of Thrones” fans shouldn’t get too excited: According to researchers, Cryodrakon looked less like Daenerys Targaryen’s fire-breathing dragons than it did a giraffe-sized, reptilian stork.

The carnivorous animal lived in modern-day Alberta during the Cretaceous period around 77 million years ago, according to a study in the Journal of Vertebrate Paleontology. It could grow to about 13 feet tall, with a wingspan of up to 30 feet, making it one of the largest flying animals ever. It had no chewing apparatus, so it would probably eat whatever was small enough to go down its gullet, including lizards, mammals and baby dinosaurs.

Like other pterosaurs, the Cryodrakon had quite awkward proportions, with a long neck, huge wings and a slender head about 3.5 times the length of its body. As one expert said, imagine a “giant flying murder head.” Alternatively: “A pair of wings that carry around a big head for guzzling things.”
Researchers said that while the pterosaur’s new name was more inspired by Alberta’s frigid landscape than it was by “Game of Thrones,” they were aware that it might elicit some comparisons.

“Yes, we had a good, personal chuckle about that,” said Michael Habib, a paleontologist at the University of Southern California and a fan of the show.

François Therrien, curator of dinosaur paleoecology at Alberta’s Royal Tyrrell Museum of Paleontology, noted that while modern-day Alberta is known for its harsh winters, the landscape that the Cryodrakon would have soared over in the late dinosaur age would actually have been a tropical paradise near a large inland sea.

An artist's illustration of the Cryodrakon boreas. (David Maas)
 
The fossils that were used to establish the Cryodrakon’s holotype — a single specimen upon which the new species is established — were discovered some 30 years ago in Alberta’s Dinosaur Provincial Park, known for being one of the richest sources of dinosaur fossils in the world. Until recently, however, the remains were thought to belong to an already known species of pterosaur, called the Quetzalcoatlus, first found in Texas.

Habib, one of the few scientists in the world who has worked extensively with Quetzalcoatlus fossils, said that when he first saw the Canadian pterosaur four years ago, he had a hunch that it was not what he had seen before. While its neck bones were long like a typical Quetzalcoatlus, its proportions did not match up.

He enlisted the help of David Hone, a specialist in pterosaur taxonomy, the classification of organisms, who realized that the remains in Alberta were exceptionally well preserved. The skeleton that researchers worked with consisted of parts of the animal’s wings, legs, neck and rib — a remarkable sample, he said, given that the bones of these types of reptiles tend to be thin and fragile, causing them to disintegrate over time.

“This type of pterosaur [azhdarchids] is quite rare, and most specimens are just a single bone,” Habib told SciTech Daily. “Our new species is represented by a partial skeleton. This tells us a great deal about the anatomy of these large fliers, how they flew, and how they lived.”

Hone had a “Eureka moment” early on when he discovered a particular pattern of holes in the fossils that seemed unique, but it took him and the other researchers several years more to cross-check the specimen with pterosaur remains in Mongolia, France and elsewhere to confirm that this was a new species, he said.
Now that they have, however, the possibilities for future research are expansive, Therrien said.
“I tell my students all the time, taxonomy is the most fundamental bit of biological science,” said Hone, director of the biology program at Queen Mary University of London. “If you don’t know what species you’ve got, how do you know what else is going on?”

quarta-feira, 30 de maio de 2018

World's Largest Pterosaur Jawbone Discovered in Transylvania


World's Largest Pterosaur Jawbone Discovered in Transylvania
The reconstructed skull of Dracula, another pterosaur found in the same region of Romania as the newly analyzed specimen.
Credit: Axel Schmidt/Dinosaurier Museum
The largest pterosaur jawbone on record has just been analyzed, and it's so big that it likely helped the prehistoric beast gulp down freshwater turtles and large dinosaur eggs for dinner more than 66 million years ago, a new study finds.

The fossil of the pterosaur's robust lower jaw is a mere 7.4 inches (18.8 centimeters) long, but the jawbone likely measured longer than a yardstick — or between 37 and 43 inches (94 and 110 cm) — when the reptile was alive, the researchers wrote in the study.

This absurdly long jaw is "more than three times the size of the complete, 290-millimeter-long [11.4 inches] holotype mandible of Bakonydraco," a pterosaur that appears to be closely related to the newly analyzed creature, the researchers wrote in the study. [Photos: Baby Pterosaurs Couldn't Fly as Hatchlings]

Study co-researcher Dan Grigorescu, a geologist at the University of Bucharest in Romania, collected the fossilized jawbone at the junction of two creeks in the Hațeg Basin, near the village of Vặlioara, which is in Transylvania, Romania, in 1984. But the fossil wasn't recognized as belonging to a pterosaur until 2011, when lead study researcher Mátyás Vremir, a geologist at the Transylvanian Museum Society, and study co-researcher Gareth Dyke, a paleontologist at the University of Debrecen in Hungary, realized its importance, according to National Geographic.
The rocks where scientists found the pterosaur Dracula. The newly studied fossil comes from the same region in Romania.
The rocks where scientists found the pterosaur Dracula. The newly studied fossil comes from the same region in Romania.
Credit: Mátyás Vremir
During the Cretaceous period, when this pterosaur was alive, Hațeg Basin was an island inhabited by dwarf dinosaurs, which were smaller than their counterparts on the mainland. Vremir unearthed the fossilized remains of one of these weird, stocky dinosaurs — a predator known as Balaur bondoc — in 2009, Live Science previously reported.

But Hațeg is also known for large pterosaurs, including Hatzegopteryx, which likely stood as tall as a giraffe, with a wingspan of up to 36 feet (10.9 meters). Another pterosaur from Hațeg, nicknamed Dracula, had an even larger wingspan of up to 39 feet (12 m).

"Islands are notorious for throwing up oddities. We have a bunch of weird dinosaurs from Hațeg and a lack of really big carnivores, so the pterosaurs were basically tyrannosaur surrogates," Dave Hone, a paleontologist at Queen Mary University of London in England, told National Geographic.
The newly studied specimen is slightly smaller than Dracula, shown here.
The newly studied specimen is slightly smaller than Dracula, shown here.
Credit: Dinosaurier Museum
But just because the newly studied pterosaur — which has yet to be scientifically named — has the largest jawbone ever found, it doesn't necessarily mean it was the biggest pterosaur on record, the researchers said. Rather, it probably had a wingspan of over 26 feet (8 m) and likely belonged to a family of pterosaurs known as the Azhdarchids, the researchers wrote in the study.

"It's always exciting to see new Azhdarchid material in the literature, especially fossils of giant pterosaurs," Kierstin Rosenbach, a doctoral student in the Department of Earth and Environmental Sciences at the University of Michigan who wasn't involved in the study, told Live Science.
The researchers discussed the different sizes and shapes of Azhdarchid pterosaurs — characteristics that are much appreciated by paleontologists who study pterosaurs, she said. That's because there appears to be a division within Azhdarchidae that the researchers elaborated on: "The authors state that Azhdarchids could have either long necks with thin skulls or short necks with robust skulls," Rosenbach said.

So, which camp does the newly analyzed pterosaur fall into? It's likely "a robust, short-skulled azhdarchid," the researchers said in the study.
The study was published online April 17 in the journal Lethaia.
Original article on Live Science.