The sauropod dinosaurs, herbivores known as “necks,” are among the largest animals to ever inhabit the Earth. Some species could reach more than 30 meters in length, but others were identified by scientists as dwarf dinosaurs. It is the case of Ibirania parva, a new species of sauropod from the group of titanosaurs that is among the smallest known and was found in Ibirá, in the interior of São Paulo. The discovery was published this Thursday in the scientific journal Ameghiniana.

Traces of the sauropod were found in the São José do Rio Preto Formation, northwest of São Paulo, known for harboring fossils of different species. The team involved in the study included researchers from national and international universities. Comparing fossils from Ibirania parva with those of its closest “relatives”, they found that the runt had unique characteristics, particularly with regard to the structure of the vertebrae, which indicated that it could belong to an as yet unnamed species.

The nomenclature chosen is the junction of Ibirá with “ania”, which means pilgrim in the Greek language, and “parva”, the Latin word for “small”. Considering that Ibirá comes from “ybyrá”, the Tupi word for “tree”, the name of the new species can be translated as “the little pilgrim of the trees”. From the material found, it was possible to estimate the size of the animal, which measured between 5 and 6 meters in length.

As among titanosaurs there are many large species, the researchers sought to identify whether it would have been a young dinosaur or if its diminutive size was a characteristic of the species. Analysis of fossilized tissue samples revealed that, at the time of its death, the animal was already an adult and had reached its final size.

The result confirmed that it is a dwarf titanosaur, the first dwarf species documented on the American continent, which lived at the end of the Cretaceous Period, about 80 million years ago. According to the researchers, the Ibirania parva adds new information about the evolution and occurrence of dwarfism in dinosaurs.

“The observed dwarfism is associated with the evolution of an endemic fauna in response to the environmental conditions of the São José do Rio Preto Formation, characterized by prolonged periods of drought”, says the study.

Geography

This phenomenon would mean that, although most dwarf dinosaurs were found in locations that corresponded to prehistoric islands, the existence of the “little tree walker” indicates that the tendency to dwarfism may occur outside insular regions, driven by characteristics ecological and geographical aspects of the environment.

Discover the Peirópolis Dinosaur Museum, in Minas Gerais