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 ~-high slope. The specimen consists of phalanges, ribs, an ulna, radius, tibia, fibula, femur, pubis, ischium, and at least ten disarticulated caudal vertebrae. 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. == Description ==