Contribution to the ichnology of the Parnaíba basin in the state of Piauí, Brazil

Ichnofossils in the Parnaíba Basin are common and abundant mainly in the Devonian sandstones of the Pimenteira Formation. The most common ichnogenera are Cruziana, Rusophycus, Bifungites, Nereites, Planolites and Scolicia. This study aims to expand the ichnodiversity of this basin with the first record of six Devonian ichnotaxa in the Pimenteira Formation. Trace fossils were collected between the years 2013 and 2019 in three outcrops in the municipality of Picos, southeastern Piauí state, Northeast region of Brazil. Six new ichnotaxa were identified: Amphorichnus papillatus, Asterosoma cf. coxii, Conichnus conicus, Didymaulichnus isp, Gyrolithes isp., and Multina isp. These trace fossils express behaviors such as feeding, dwelling, crawling, grazing and resting. The reported ichnotaxonomic novelties are attributed to an invertebrate biota that inhabited the epicontinental sea present in the region during the Devonian. The occurrence of these ichnofossils in the state of Piauí extends their areas of geographic distribution, the temporal amplitude of Amphorichnus papillatus, the ichnofossil diversity of the Pimenteira Formation and presents data on the current state of the Devonian outcrops in the municipality of Picos.