Feliz Deserto FormationThe Feliz Deserto Formation is a geologic formation of the Early Cretaceous age in northeastern Brazil's Sergipe-Alagoas Basin. The formation belongs to the rift phase, in which a great lake formed.BackgroundThe formation provides vertebrate fossils of Lepidotes fish and teeth of crocodylomorphs and theropods, including what may be the oldest members of the Spinosauridae reported in South America.