Discovery and naming
The holotype of Dasosaurus, CPHNAM VT 1600, was discovered by Daniel Ribeiro da Silva, an archeologist, in outcrops of the Itapecuru Formation in Davinópolis, Maranhão, Brazil. da Silva found the fossils exposed at the base of an ~8 m (26 ft)-high slope. The specimen consists of phalanges, ribs, an ulna, radius, tibia, fibula, femur, pubis, ischium, and at least ten disarticulated caudal vertebrae.[1]
In 2026, Elver L. Mayer and colleagues described Dasosaurus tocantinensis as a new genus and species of somphospondylan sauropod based on these fossil remains, establishing CPHNAM VT 1600 as the holotype specimen. The generic name, Dasosaurus, combines the Greek words dasos, meaning 'forest'—in reference to the type locality in Amazônia Legal, a division of Brazil that includes majority of Amazon rainforest—and saurus, meaning 'lizard'. The specific name, tocantinensis, is after Tocantins, a state near the state of Maranhão where the type locality is situated.
