Miraxis Gegas A new species of dinosaur with disproportionately short arms has been discovered T-Rex his job Miraxis Gegas.
Dinosaurs (such as the notorious T-Rex) is not the only group of giant carnivorous dinosaurs with small arms. In fact, paleontologists have discovered a new species of dinosaur with completely disproportionately short arms. T-Rex his job Miraxis Gegas. The results are published in the journal current biology Argue Today (7 July) T-Rex and the M Gegas It was developed to have small arms completely independently, and it identified many potential functions of small arms, such as mating or supporting movement.
‘fossil’ M Gegas Never seen before, it shows entire areas of the skeleton such as arms and legs that have helped us understand some of the evolutionary trends and anatomy of Carcharodontosaurids – the group that M Gegas It “belongs,” says Juan Canal, project leader at the Ernesto Bachmann Museum of Paleontology in Neuquén, Argentina.
First, to make things right, the authors say so T-Rex They didn’t take their short arms from M Gegas Or vice versa. Not only M Gegas It became extinct about 20 million years ago T-Rex They have become a species, but in the evolutionary tree they are also very far apart. “There is no direct relationship between them,” Kanal says. Instead, Kanal believes that having small arms somehow gives dinosaurs a survival advantage.
Miraxis Gegas It is a giant carnivorous dinosaur. Credit: Carlos Papilio
I am convinced that these relatively small arms have some kind of function. The skeleton showed large muscular attachments and a fully developed chest, so the arm had strong muscles,” Kanal says. This shows that the arms did not contract because they were useless for dinosaurs. The more difficult question is what exactly were the functions.
From previous studies, the research group proved that for dinosaurs like M Gegas and the T-RexThe bigger their heads, the smaller their arms. They certainly weren’t useful for hunting, because “acts related to predation may have been done through the head,” Kanal says.
“I tend to think that your arms were used for other types of activities,” Kanal says. From the fossil record, the team was able to paint a picture of this life. M Gegas before I die. The dinosaur lived in what is now northern Patagonia, Argentina, and was 45 years old, about 11 meters long and weighing more than four tons. And she had a big family. “The group thrived and peaked in diversity just before the extinction,” Kanal says. “They may have used their arms for reproductive behaviour, such as holding the female during mating or leaning back after breaking or falling,” Canall adds.
drilling site Miraxis Gegas. Credit: Juan I Channel
The team also found that the skull M Gegas They are decorated with signs, grooves, spurs and small horns. “These forms appear late in development when individuals become adults,” Kanal says. The group believes that the funds may have been used to attract potential partners. “Sexual selection is a powerful evolutionary force. But since we cannot directly observe their behavior, it is impossible to be sure,” Kanall says.
“The fossil has a lot of new information in it and it’s in great shape,” Kanall says. He looks forward to exploring other questions he asks. M Gegas Fossil can help you with the answer. “We found the perfect place on the first day of searching and M Gegas “It was probably one of the most exciting points of my career,” Kanal says.
Reference: “New Giant Carnivorous Dinosaur Reveals Converging Evolutionary Trends in Arm Reducing Theropod” by Juan I. Canal, Sebastian Apisteguia, Pablo A. Galena, Jonathan Mitchell, Nathan D. Smith, Thomas M. Colin, Akiko Shinya, Alejandro Halusa, Federico Giancini, Peter J. Makovsky, July 7, 2022, Available here. current biology.
DOI: 10.1016 / j.cub.2022.05.057
This work was supported by the US National Science Foundation and the National Geographic Society.
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