A new giant dinosaur provides insight into why so many prehistoric carnivores had such tiny arms
A team led by a University of Minnesota Twin Cities researcher Peter Makovicky and Argentine colleagues Juan Canale and Sebastian Apesteguía discovered a new species of giant carnivore dinosaur, named Meraxes gigas. The new dinosaur species provides clues to the evolution and biology of dinosaurs like Carcharodontosaurus and Tyrannosaurus rex – specifically why these animals had such large skulls and tiny arms..
An international team including a University of Minnesota Twin Cities researcher has discovered a large, new species of carnivorous dinosaur, named Meraxes gigas (illustrated above), providing clues to the origins of the dinosaurs. Evolution and anatomy of predatory dinosaurs such as Carcharodontosaurus and Tyrannosaurus rex. Image credit: Jorge Gonzalez
The study was published in Current biologya peer-reviewed scientific biology journal.
Researchers originally discovered Meraxes in Patagonia in 2012 and have spent the past several years extracting, preparing, and analyzing the specimen. This dinosaur was part of the family Carcharodontosauridae, a group of giant carnivorous arthropods that included Giganotosaurus, one of the largest known carnivorous dinosaurs and one of the movie’s reptilian stars. “Jurassic World: Dominion” was released recently.
Although not the largest of the carcharodontosaurids, Meraxes was a massive animal, measuring about 36 feet from snout to tip of tail and weighing about 9,000 pounds.
Meraxes is one of the most complete carcharodontosaurid skeletons that paleontologists have found in the Southern Hemisphere to date.
Makovicky, one of the study’s lead authors and a professor in the University of Minnesota NH Winchell’s School of Earth and Environmental Sciences, said: Tyrannosaurus rex like T. rex. “But, they don’t have a close relationship with T. rex. They come from very different branches of the carnivorous family tree. So this new discovery allows us to probe the question, ‘Why were these carnivorous dinosaurs so big and had such tiny arms?’ “
With the statistical data Meraxes provided, the researchers found that large, carnivorous dinosaurs in all three families of healing animals evolved in similar ways. As they evolved, their skulls grew larger and their arms gradually shortened.
The possible uses of the tiny forelimbs in T. rex and other large carnivorous dinosaurs have been the subject of much speculation and debate.
“What we are suggesting is that there is another way of doing this,” Makovicky said. “We shouldn’t worry too much about what the arms are being used for, because the arms are actually shrinking as a result of the skull getting so big. Whatever the arms may or may not be used for, they take on a secondary function because the skull is being optimized to handle larger prey.”
Source: University of Minnesota
