 "B. mariantensis" is known from two specimens, including the holotype UFRGS-PV-0168-T, a complete skull, atlas, axis and third neck vertebra and the paratype UFRGS-PV-0315-T, right maxilla and jaw, both housed at the vertebrate paleontology collection of the Universidade Federal do Rio Grande do Sul, Porto Alegre-Brazil.The specimens were collected at the same site, along road RS-240 near the town of Porto Mariante, 28 km east of Venâncio Aires, in the municipality of Bom Retiro do Sul.Since its first description by Langer & Schultz (2000) it became known in the scientific literature as the "Mariante Rhynchosaur" in reference to the town of Porto Mariante.