Irati Formation is the name of a geological formation of the Paraná Basin in Brazil. It has previously been dated as Late Permian using palynomorphs, but is now dated as Early Permian using zircon ages obtained from bentonite layers. The base of the formation has been dated at 278.4 ± 2.2 Ma.Da Costa, 2015, p.28Ventura Santos et al., 2006 Exposures of the Irati Formation are to be found in the South (Geopark of Paleorrota), southeastern Brazil and in the states of Goiás, Mato Grosso, São Paulo, Paraná, Santa Catarina, Rio Grande do Sul and Mato Grosso do Sul. The formation is part of the Passa Dios Group, underlying the Serra Alta Formation and overlying the Palermo Formation. The formation has been deposited in a restricted marine environment.Diduch, 2011, p.21 The Irati Formation, with a maximum thickness of , was defined and named by White in 1908.Da Costa, 2015, p.12
Fossil content
Reptiles Reptiles of the Irati Formation Genus Species Location Stratigraphic position Material Notes Image Brazilosaurus B. sanpauloensis A mesosaurid mesosaur Mesosaurus M. tenuidiens A mesosaurid mesosaur Stereosternum S. tumidum A mesosaurid mesosaur
Fish Fish of the Irati Formation Genus Species Location Stratigraphic position Material Notes Images Amelacanthus A. sp. A ctenacanthid sharkFairchildodus F. rioclarensis A petalodont Iratiacanthus I. santamariaensis A sphenacanthid shark Itapyrodus I. punctatus A petalodont Orodus O. ipeunaensis A orodontid shark Sphenacanthus S. sanpauloensis A sphenacanthid shark Taquaralodus T. albuquequei A diplodoselachid shark Xenacanthus X. pricei A xenacanthid shark
Crustaceans Crustaceans of the Irati Formation Genus Species Location Stratigraphic position Material Notes Images Iraticaris I. damiani Myelontordoxylon M. camposii Permocaris P. purperae Pittinucaris P. wuerdigae
See also
Ganigobis Formation
References
Bibliography