The holotype (MN 4802-V) consists of 3 caudal vertebrae with chevrons, ischia, femora, tibia, fibula, pes, and soft tissue. The fossilized tissue includes a thin epidermis, muscle fibers, and possibly blood vessels.[1] The type species is S. placidus, first described by Kellner in 1999.[5] The species epithet refers to Placido Cidade Nuvens, who founded the Museo de Santana do Cariri.[1]