Irati Formation
Geologic formation in Brazil
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. 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. The Irati Formation, with a maximum thickness of 80 metres (260 ft), was defined and named by White in 1908.
01Fossil content
| Color key | |||||||
|---|---|---|---|---|---|---|---|
| Taxon | Reclassified taxon | Taxon falsely reported as present | Dubious taxon or junior synonym | Ichnotaxon | Ootaxon | Morphotaxon | |
Notes
Uncertain or tentative taxa are in small text; crossed out taxa are discredited.
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 shark | ||||
| Fairchildodus | 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 | |||||
Sources and credits
This article is adapted from the Wikipedia article “Irati Formation”, written by its contributors and licensed under CC BY-SA 4.0. Fathomly has changed the layout, removed citation markers, navigation and maintenance notices, and adjusted punctuation. This adapted version is shared under the same license. For references, see the original article.
Images, from Wikimedia Commons:
- Parana Basin simplified stratigraphic chart.png by GeoPotinga, CC BY-SA 3.0
- Brazilosaurus sanpauloensis.jpg by Ghedo, CC BY-SA 4.0
- Mesosaurus BW.jpg by Nobu Tamura (http://spinops.blogspot.com), CC BY 2.5
- Stereosternum.jpg by Smokeybjb, CC BY-SA 3.0
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