First occurrence of fossil shrimps (crustacea, decapoda) in the Ipubi Formation (Lower cretaceous, Araripe Basin)

The Ipubi Formation of the Araripe Basin is an important gypsum cretaceous reserve whose environment had resulted in the deposition of evaporites with narrow black shale lenses. In this work, we present the first occurrence of caridean for the dark shale levels of the Ipubi Formation. The analyzed specimen, although not achieving a detailed taxonomic determination, is a very important one because it is the first decapod crustacean found in this formation. We believe the specimen LPU-0918/A and B, is a caridean because of its second abdominal somite having a strongly rounded pleura in the base and it apparently overlaps the first and the third. The knowledge about fossil shrimps is still sparse, and the information presented here can be valuable to the understanding of the evolutive history of the carideans