Middle and Late Devonian Chitinozoa and biostratigraphy of the Parnaíba and Jatobá Basins, northeastern Brazil

Chitinozoans from Middle and Upper Devonian strata have been investigated in the Parnaíba and Jatobá basins of northeastern Brazil. The 63 chitinozoan species encountered include 32 species retained in open nomenclature due to the insufficient number of well-preserved specimens, and seven species described as new, viz., Ancyrochitina arirambaense, Angochitina parnaibaense, Angochitina smallii, Fungochitina microspinosa, Ramochitina kegelii, Ramochitina pimenteiraense, and Ramochitina stiphrospinata. A regional chitinozoan biozonation, consisting of six zones, is proposed for the investigated interval. These zones are, from the oldest to the youngest: interval range zone of Ancyrochitina latipes (Eifelian s.l.); concurrent range zone of Ancyrochitina latipes and Ancyrochitina langei (late Eifelian); total range zone of Ramochitina stiphrospinata n. sp. (early Givetian); interval range zone of Fungochitina microspinosa n. sp. (middle Givetian); interval range zone of Lagenochitina avelinoi (Frasnian s.l.); and the concurrent range zone of Urochitina bastosii and Sommerochitina langei (late Frasnian - middle Famennian).