A newly identified dinosaur species, discovered during construction in northeastern Brazil, is shedding light on how giant dinosaurs once roamed across ancient continents. The species, named Dasosaurus tocantinensis, lived about 120 million years ago and measured around 20 meters long—roughly the length of a school bus. Its fossils were found in Davinópolis, a city in the state of Maranhão, during the construction of a rail terminal. This discovery is significant because Dasosaurus is closely related to a species found in what is now Spain, suggesting that these dinosaurs once lived across regions that are now divided by the Atlantic Ocean. At the time Dasosaurus lived, South America, Africa, and parts of Europe were connected as part of the supercontinent Gondwana. Researchers believe the ancestors of Dasosaurus tocantinensis may have migrated to South America through North Africa during the period between 140 and 120 million years ago. This finding adds to the growing evidence that dinosaurs were once widespread across continents that are now separated by oceans. Elver Luiz Mayer, a professor at the Federal University of the São Francisco Valley (UNIVASF), became involved with the discovery in 2021. Initially, the fossils were mistaken for those of large prehistoric mammals, but Mayer quickly realized they were much older. He identified the age of the geological layer as being from the transition between the Lower and Upper Cretaceous periods, about 120 million years ago. Mayer then brought in experts to study the remains, forming a multidisciplinary team to analyze the fossils. The specimen, now housed in São Luís, the capital of Maranhão, includes several major bones, making it one of the most complete dinosaur fossils of its kind. The name Dasosaurus reflects the region where the fossils were found. "Daso" refers to the forested landscape of Maranhão, a term early Portuguese colonizers used to describe the dense vegetation. "Tocantinensis" refers to the Tocantins River, which is near the fossil site. Researchers also studied the microscopic structure of the dinosaur's bones and found that its growth patterns combine traits seen in older sauropods with features found in titanosaurs, a group of large, long-necked dinosaurs. This suggests that certain bone growth patterns may have evolved earlier than previously thought, potentially explaining how some sauropods grew so large. The discovery highlights the dual role of construction projects in paleontology. While such projects can damage fossil sites, they can also expose layers of rock that would otherwise be difficult to access. In Brazil, where dense vegetation covers much of the landscape, construction often reveals hidden fossils. However, experts stress the need for better coordination between construction companies and scientists to ensure proper excavation and preservation of these important finds. Researchers are now working to gain permission to return to the site and continue their work, hoping to uncover more about Dasosaurus tocantinensis and its place in the broader history of dinosaurs.