Non-marine ostracoda from the Aliança Formation in the north-central portion of the Jatobá Basin, Northeastern Brazil

Abstract

This study presents the non-marine ostracode fauna from three localities of the Aliança Formation (upper Jurassic?), in the north-central portion of the Jatobá Basin. Twenty-two samples were collected in the municipality of Ibimirim, Pernambuco, Brazil, distributed in three sections. The ostracode assemblage, characteristic of freshwater bodies, is composed by the following species: Theriosynoecum pricei (Pinto & Sanguinetti, 1958), T. uninodosa (Pinto & Sanguinetti, 1958), T. quadrinodosum Krömmelbein & Weber, 1971, Reconcavona? jatobaensis Krömmelbein & Weber, 1971 and Alicenula? spp. The occurrence of Reconcavona? jatobaensis possibly constitutes the oldest known record of this species. The age of the Dom João local stage, characterized by its endemic ostracode fauna is hitherto a topic of debate in northeastern Brazilian basins studies, and is here briefly discussed as well.