University of São Paulo: Discovery of New Titanosaur Species Reveals Evolutionary Novelties
In Jurassic Park , humanity’s curiosity to learn more about dinosaurs led it to recreate different species of the animal using DNA preserved in ancient amber. Outside of fiction, we can discover a little more about these prehistoric animals, extinct for more than 65 million years, through paleontology and its studies.
Recently, the National Council for Scientific and Technical Research of Argentina ( Conicet ) discovered a new species of titanosaur, Titanomachya gimenezi , which would have lived in the Patagonia region during the late Cretaceous period. According to Julian Cristian da Silva Junior, PhD from the Faculty of Philosophy, Sciences and Letters of Ribeirão Preto (FFCLRP) at USP, titanosaurs, of which several species have been described worldwide, are the group that represents the greatest variation in size within the sauropods, of which they are a part. Unlike brachiosaurs, another important branch of sauropods, titanosaurs diversified more in the southern region of the planet, when the continents were still connected — Gondwana.
“We have individuals ranging from the smallest to gigantic, which are also part of the titanosaur group. The fact is that, within the titanosaurs, there is a lineage that we call Saltasauridae , known for being smaller. In fact, it has a representative in Brazil; a new species was recently discovered in the interior of the state of São Paulo called Ibirania ,” he says. According to Luiz Eduardo Anelli, a professor at the Institute of Geosciences (IGc) at USP and author of books on dinosaurs published by the University of São Paulo Press (Edusp), unlike dwarfism, which is a genetic syndrome, dwarf dinosaur species simply underwent evolutionary processes that made them smaller, a characteristic that does not serve as taxonomic validity.
Characteristics of Titanomachya
To distinguish one species from another, Silva Junior explains that paleontologists use unique anatomical characteristics. “The Titanomachya has some characteristics in its skeleton that are different from all other titanosaurs. But what caught the media’s attention was its size, with an estimated weight of around seven tons, more or less the same weight as an adult African elephant,” he adds. In addition to its weight, which is considered small, the dinosaur was approximately only eight meters long, according to Anelli.
He states that one of the bones that differentiates the species from others is the astragalus, an ankle bone that reinforces the legs, which in Titanomachya is very reinforced and has distinct characteristics from the groups related to it in Argentina. “This robust astragalus, with its bones, may be an ancient characteristic, but one that has not yet been found in previous species, which had the same astragalus, or it may be something new,” he says.
The professor also confirms that, despite the differences, Titanomachya has related species, something very common throughout evolutionary history. He concludes: “At the end of the Cretaceous, animals were diversifying, each one occupying its niche, and they are related. It is evolution that preserves life, because environments change and the lives of 1 million years ago are no longer suitable for this moment.”
Patagonia and paleontology
According to Silva Junior, Patagonia is a very important region for paleontology: “It is a region with a very large abundance of fossils and, because it is a more arid region, with little vegetation, it makes excavation easier, because it is one thing to excavate in a desert, another thing to excavate in an Amazon rainforest, for example. So there are many dinosaurs that came from there.”
The expert explains that these studies serve to try to fill gaps in the evolutionary history of the Earth, since the animals and plants that we have today represent a very small fraction of everything that has ever existed on the planet. “To know how we got to where we are today, evolutionarily, it is important to review this history, which is found in the fossils. You can follow the evolution of these groups, from living groups, such as birds, mammals, reptiles, to completely extinct groups, such as these large dinosaurs,” he adds.
For Anelli, Argentina is a great example of the importance of paleontological studies, since the climate during the Cretaceous period greatly favored the development of forests and, consequently, of several sauropods and other dinosaurs in the region. In addition, paleontology is highly valued in the country, as the professor explains: “Argentines have this to teach us, they explore their prehistory with hundreds of books, documentaries, museums, they explore tourism, and all of this is sophisticated knowledge. People’s quality of life is multiplied dozens of times because of this wonderful knowledge.”