Post by account_disabled on Mar 13, 2024 22:46:22 GMT -5
In a study published on Friday (11) in the North American journal Journal of Vertebrate Paleontology, researchers from UFSM present a new fossil that provided information about the evolution of the body size of dinosaurs. The article is titled “A sauropodomorph (Dinosauria, Saurischia) specimen from the Upper Triassic of southern Brazil and the beginning of size increase in Sauropodomorpha” ( A sauropodomorph (Dinosauria, Saurischia) specimen from the Upper Triassic of southern Brazil and the early increase in size in Sauropodomorpha ) and can be viewed here . Dinosaurs were the largest land animals that ever walked the planet, with some forms reaching more than 30 meters in length and weighing tens of tons. But it was not always so. When dinosaurs first emerged, around 233 million years ago, they were much smaller, averaging 1.50 meters long and weighing between 7 and 10 kg. Dinosaurs excavated from fossil sites around 225 million years ago measured around 4 meters in length and weighed more than 100 kg. This increase in size over an interval of 8 million years required a series of changes in the skeleton, which had to support more weight and face new challenges related to body balance.
Many of these adaptations have already been identified by researchers, but doubts still remain regarding when they emerged and the order in which they were established. To resolve this question, fossils are needed that fill this 8 million year gap. Precisely in a fossil site located in this interval, in February 2021, the paleontologist from the Support Center for Paleontological Research of the Quarta Colônia (Cappa) of UFSM, Rodrigo Temp Müller, identified a new fossil skeleton in the municipality of Agudo, in the central region from Rio Grande do Sul. The fossil belongs to a dinosaur just over 2.20 meters DM Databases long. Through this discovery, it was possible to investigate what was happening to the skeleton of these dinosaurs during this phase in which they began to grow. In addition to the paleontologist, biologist Maurício Silva Garcia, a master's student in Animal Biodiversity at UFSM, also participated in the study. Both are the authors of the article mentioned above. Paleoartist Márcio Luiz de Castro created an illustration of what the dinosaur found in Agudo in 2021 would look like Due to the lack of certain bones, it was not possible to identify the species to which the fossil belongs.
Even so, an analysis indicated that the animal should weigh around 21 kg. This corresponds to approximately three times more than the dinosaurs found in slightly older fossil sites. On the other hand, an unexpected result indicated that, even with this clear increase in size and weight, the skeleton lacks the adaptations observed in larger forms. For example, the bones are thin, the leg maintains the typical configuration seen in running animals and the muscle attachment structures still have the same shape as those found in smaller dinosaurs. The discovery of this information is particularly interesting because it reveals that sk the early evolution of the group. It is now known that dinosaurs were gradually growing larger during the group's early evolution. However, the most significant changes related to weight gain only occurred close to the moment they exceeded 100 kg. The combination of this discovery and a series of previous discoveries made in South America and Africa have increasingly shed light on the details of how dinosaurs emerged and evolved to the point where they became the dominant animals in the ecosystems in which they occurred.