In the words of an old construction adage, “behind every wall is a surprise.” Ask any contractor, and they can tell you a handful of stories. They can talk about the bizarre things they uncover on job sites till they’re blue in the face. Carpenters reveal hidden rooms, while landscapers stumble upon buried coins. But the Earth was here long before humans pressed our feet into its soft clay. If you dig down deep enough, you might just find the bones of true titans… Which is exactly what happened to an unsuspecting construction crew in Davinópolis, Maranhão, Brazil.
An Unexpected Shift in the Soil
Initially discovered in 2021, contractors digging a foundation for a road-rail terminal unearthed an impressive array of large skeletal remains. Found roughly 8 meters (26 feet) deep, work was immediately halted so state-mandated archaeologists could excavate the find. Initial conjecture pegged the remains as belonging to a large prehistoric mammal. However, the bones needed rigorous testing and were packed up for evaluation. Following a lengthy preparation process, they were sent to Pará, Brazil, for formal identification.
Professor Elver Luiz Mayer of the Federal University of Southern and Southeastern Pará took over the case when the remains arrived at his university. Mayer, who generally studies ancient mammals, knew instantly that given the depth of the discovery, these remains were “much older” than initial reports suggested. Previous surveys of the extraction site showed that rock formations at that depth dated back “120 million years” to the Lower and Upper Cretaceous periods.
Dasosaurus Tocantinensis: Unveiling a Cretaceous Titan
Because no large mammals existed during that period of time, all signs pointed to one conclusion. The construction team had stumbled upon a dinosaur. Mayer immediately formed a diverse team of specialists to study the bones. Five years after the discovery, Mayer and his team have officially confirmed that the bones do belong to a dinosaur. And most recently, it has been declared an entirely new species.
Hailing from the Sauropod family (think Brontosaurus), the freshly named Dasosaurus tocantinensis stands as a moderately sized addition to the sauropod family tree, but a giant for the region. Research shows this Dasosaurus was around 20 meters long.
Fortunately, the specimen itself is considered relatively complete, with intact tail vertebrae, ribs, arms, legs, and foot bones; Mayer and his team were able to accurately map the dinosaur’s sheer size and profile. This makes Dasosaurus the largest addition to Maranhão’s dinosaur roster, coming in 10 meters larger than the Amazonsaurus, the state’s previous record-holder.
Bridges to the Past, Lessons for the Future
One of the most fascinating aspects of the new sauropod is its origins. Its closest genetic relatives have been unearthed in Spain. This implies that sauropods once walked freely between South America and Europe—a trip made possible because the world was composed of interconnected supercontinents. Dasosaurus ancestors likely spread across modern-day Europe and the Americas via North Africa through the supercontinent Gondwana.
The excavation of Dasosaurus tocantinensis also highlights the current state of paleontology, where the truth of the matter is that most excavation sites are stumbled upon by accident. A direct correlation exists between large civil works projects and the discovery of fossils. While many countries have regulations to foster cooperation when deposits are found, enforcement and reporting are wildly inconsistent. Just as many sites are destroyed by the machines of progress as are saved by them. Brazil, being heavily forested, relies heavily on public works to expose potential fossil deposits.
Professor Mayer emphasizes that “closer cooperation” between paleontologists and construction companies is vital. Moving forward, there is a clear need to reconcile critical infrastructure projects with federal heritage legislation, ensuring we can build the future without destroying the secrets of our past. The discovery of Dasosaurus tocantinensis shows why cooperation between construction companies and paleontologists remains so important.
