When they were first published, in 1993, the Crato Formation limestones provided a new pterosaur site, which also preserved insects that fell into a brackish lagoon and semionotid fish. The fossils are usually compacted and preserved in layers of limestone. Fossil Odonata (dragonflies) and damselflies are especially rich in the Crato lagerstätte: currently 384 specimens have been recovered, 264 adults and 120 larvae.