Newly Discovered Dinosaur Offers Insights into Ancient Species Migration

A remarkable dinosaur species, *Dasosaurus tocantinensis*, has recently been unveiled during construction work in northeastern Brazil, providing new insights into the migration of giant dinosaurs across ancient landscapes.

This species, measuring approximately 20 meters in length and existing around 120 million years ago, was detailed in a study featured in the *Journal of Systematic Palaeontology*. Its fossils were uncovered at a construction site for a road rail terminal in Davinópolis, Maranhão.

Unexpected Evolutionary Pathways

A particularly intriguing aspect of this discovery is the dinosaur's evolutionary link to Europe. The closest relative of *Dasosaurus tocantinensis* is known from Spain, indicating that these creatures once occupied territories now divided by the Atlantic Ocean.

Researchers suggest that the ancestors of this dinosaur likely migrated to South America via North Africa, during a period when these continents were still connected as part of the supercontinent Gondwana, roughly between 140 and 120 million years ago.

Significance of the Find

This discovery marks the largest known dinosaur in Maranhão, a region that harbors smaller species such as the diplodocid *Amazonsaurus maranhensis*, measuring about 10 meters. Elver Luiz Mayer, a professor at the Federal University of the São Francisco Valley, emphasizes the significance of unearthing such a large sauropod for the area.

Mayer's involvement began in 2021 while he was conducting research in São Félix do Xingu and later connecting the dots regarding the significance of the fossils found at Davinópolis. Initially believed to belong to large prehistoric mammals, Mayer recognized the true age of the bones—approximately 120 million years—based on their depth and associated geological formations.

Unveiling the Fossil Specimen

The fossil remains were initially discovered under the supervision of archaeologists monitoring the construction project as part of environmental regulation compliance. After Mayer's analysis led to a multidisciplinary study involving various specialists, the specimen underwent extensive preparation before being transferred to the State Center for Natural History and Archaeology Research in São Luís.

This preserved dinosaur skeleton, which includes essential bones such as tail vertebrae, a 1.5-meter femur, ribs, and limb bones, is relatively comprehensible compared to its counterparts. Max Langer, a professor at the University of São Paulo involved in the research, suggests that further excavations may yield additional fossils from this individual.

Understanding Bone Growth Patterns

Additional research into the microscopic structure of *Dasosaurus* bones, led by scientists from the Federal University of Rio Grande do Norte, indicated growth patterns that exhibit a mix between older sauropods and titanosaurs. This finding may push the timeline for certain bone growth and remodeling characteristics in dinosaurs back further than previously considered.

Construction Dynamics and Paleontological Impacts

The *Dasosaurus* discovery highlights a complex dynamic in paleontology: while large construction projects pose risks of damaging fossil deposits, they can also expose geological layers rich in fossils. As Langer notes, Brazil's dense tropical vegetation often obscures geological formations, making human activity essential for uncovering fossils that would otherwise remain hidden.

However, Langer cautions that such activities necessitate specialized monitoring and recovery efforts, which can sometimes be neglected in the rush of development. To ensure the preservation of invaluable fossil records while accommodating construction needs, Mayer advocates for enhanced collaboration between development entities and paleontological preservationists.

Next Steps for Research

Currently, researchers are in discussions with the construction firm to gain permission for continued excavation at the site. The potential for further discoveries surrounding *Dasosaurus tocantinensis* could enrich our understanding of the diverse adaptations and migrations of dinosaurs in ancient ecosystems.

The project received significant support from FAPESP, including scholarships and grants, facilitating the team's efforts to delve deeper into the history of this newly discovered dinosaur species.