Dasosaurus tocantinensis fossils link South American sauropods to European relatives via 120-million-year-old Gondwanan corridor

Construction monitoring for a rail terminal in Davinópolis uncovered vertebrae, a 1.5 m femur, ribs and limb bones initially mistaken for Quaternary mammals. Depth and formation age prompted re-dating to the Lower-Upper Cretaceous transition. Preparation in Pará and return to São Luís yielded a relatively complete specimen now housed at the State Center for Natural History and Archaeology. Histological sections indicate rapid juvenile growth consistent with other titanosauriforms. The find expands Maranhão’s dinosaur record beyond the smaller diplodocid Amazonsaurus.

Phylogenetic placement nests Dasosaurus with a Spanish titanosauriform, supporting a 140–120 Ma dispersal corridor through still-connected North Africa. This timing aligns with the final rifting phases of West Gondwana and challenges models that assumed complete isolation of South American faunas by the Aptian. The specimen’s completeness allows character scoring that previous fragmentary South American taxa lacked, tightening node ages for the European–South American split.

Future fieldwork at the same site is expected to recover additional elements from the same individual. Comparable Cretaceous outcrops along the Tocantins basin remain undersampled; systematic prospecting could test whether the lineage persisted until later in the Cretaceous or was replaced by endemic titanosaur radiations. Integration with existing FAPESP-funded projects on South American Cretaceous faunas will clarify whether similar trans-Atlantic signals appear in other clades.