Marília formation

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The Marília Formation is a sequence continental sedimentary rocks from the Upper Cretaceous that in southern Brazil open is. It belongs to the Bauru Group and is located in the Paraná Basin . This lithostratigraphic formation is famous for its vertebrate fossils, which include the remains of dinosaurs . The formation is divided into three units (sub-formations) - the Echaporã member, the Serra da Galga member and the Ponte Alta member. The São José do Rio Preto Formation borders in the south .

The rocks of the formation are mostly coarse-grained to conglomerate sandstones , clayey siltstones and layers of carbonate . The climate at the time of the deposits was hot and dry. Long periods of drought were interrupted by periodic heavy rains, which formed temporary small lakes. The deposits come from alluvial fans , alluvial plains and short-lived lakes.

The formation is dated to the Maastrichtian , based on fossils of charophytes and ostracods ( biostratigraphy ).

Fossil content

The Peirópolis site near the city of Uberaba in the Brazilian state of Minas Gerais is particularly famous for its wealth of fossils . This occurrence has been known since 1920, but was not scientifically investigated in more detail until 1947 with the field studies of the paleontologist Llewellyn Ivor Price . Vertebrate fossils include fish , the frog Baurubatrachus , the lizard Pristiguana , the turtle Cambaremys that crocodiles Itasuchus , Peirosaurus and Uberabasuchus and theropod and sauropod dinosaur with a: theropods are with remains of Abelisauriden , Carcharodontosauriden and Maniraptoren represented, while sauropods by Titanosaurier baurutitan , Trigonosaurus , Uberabatitan and Aeolosaurus are represented.

Individual evidence

  1. ^ A b Leonardo Salgado , Ismar de Souza Carvalho: Uberabatitan ribeiroi, a new titanosaur from the Marília Formation (Bauru Group, Upper Cretaceous), Minas Gerais, Brazil. In: Palaeontology. Vol. 51, No. 4, 2008, ISSN  0031-0239 , pp. 881-901, doi : 10.1111 / j.1475-4983.2008.00781.x .
  2. ^ FE Novas, LC Borges Ribeiro, Ismar de Souza Carvalho, 2005: Maniraptoran theropod ungual from the Marília Formation (Upper Cretaceous), Brazil . In: Rev. Mus. Argentino Cienc. Nat., Ns, Volume 7, Number 1, Pages 31-36, ISSN  1514-5158 .
  3. ↑ CRA Candeiro, 2009: Vertebrates of the Marilia Formation (late Maastrichtian) from the Peirópolis paleontological site: Toward a better understanding. In: Earth Sciences Research Journal, number 13, volume 1, pages 6-15.