New occurrences of vertebrate fossil eggs from the Late Cretaceous of the Bauru Group

Author(s)

Julio Cesar de Almeida Marsola

• Document type: Master's Dissertation
• Press: Ribeirão Preto.
• Institution: Universidade de São Paulo (USP). Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (PCARP/BC)
• Defense date: 2013-04-02

Examining board members

Max Cardoso Langer; Wilfried Klein; Rodrigo Miloni Santucci

• Advisor: Max Cardoso Langer

Abstract

Amniotes fossil eggs, such as Crocodyliformes, Aves and Chelonii, are known from few places worldwide, and the Mesozoic records are particularly rare. Similarly, the occurrence of eggs of these groups is also rare in Brazil and limited to few crocodylian eggs and a single Chelonii one from Cretaceous rocks. This work aimed to describe twelve fossil eggs collected in Campina Verde-MG, and two additional eggs from Álvares Machado and Pirapozinho, SP, all from Bauru Group rocks (Upper Cretaceous). The ultrastructural traits of the shells were analyzed by Scanning Electron Microscopy, Energy Dispersive Spectroscopy and Optical Microscopy, in addition, Computadorized Tomography was applied to check the embryos occurrence. The twelve eggs from Campina Verde are associated to Crocodyliformes. In addition, the topotipic principle suggests an association of these eggs to the crocodyliform Pissarrachampsa sera. Additionally, the recurrent association of notosuchians fossil eggs and skeletal remains suggests a level of parental care in this group. The specimen from Álvares Machado is associated to Enantiornithes, and the egg from Pirapozinho shares traits with Podocnemidae eggs, which is the only known Chelonii group found in the outcrop where the egg came from (AU)