A possible chelonian egg from the Brazilian late cretaceous

Abstract

This paper describes a possible fossil egg proceeding from the Bauru Group, Late Cretaceous of Paraná Basin, Brazil. External morphology, dimensions, texture and shell ornamentation examined under electron microscopy show close resemblance to the Recent podocnemidid chelonian eggs. Association with bony material in the outcrop suggests that it is related to a species of Podocnemis. Computerized tomography reveals a high density outer region corresponding to the shell component layers, and successive layers with decreasing density towards the nucleus. An area of high density in the central region may represent remains of an embryo.

A Review of the Fossil Record of Turtle Reproduction: Eggs, Embryos, Nests and Copulating Pairs

“…Many authors have attempted to identify the species of turtle that potentially laid a given fossil egg (Gergens 1860;Meyer 1860;Hummel 1929;Kohring 1993;Gaffney 1996;Azevedo et al 2000).…”

An occurrence of fossil eggs from the Mesozoic of Madagascar and a detailed observation of eggshell microstructure

“…The Malagasy eggs are only the fifth documented occurrence of Mesozoic turtle eggs from Gondwanan continents, following two specimens from Brazil (Azevedo et al, 2000;Marsola et al, 2014) and two from India (Sahni, 1957;Mohabey, 1998). The specimens described by Azevedo et al (2000) and Sahni (1957) were identified only by gross morphology, however, and microstructural analysis was not performed.…”

“…The specimens described by Azevedo et al (2000) and Sahni (1957) were identified only by gross morphology, however, and microstructural analysis was not performed. Additionally, many have questioned a turtle origin for the specimens described by Mohabey (1998) because of low-quality figures and the identification of a mammillary layer at the basal-most portion of the eggshell (Kohring, 1999;Jackson et al, 2008;Knell et al, 2011).…”

Overview of the Late Cretaceous Biota of the western São Paulo State, Brazil, Bauru Group

“…Clutches of small eggs have been referred to podocnemidid (Azevedo et al, 2000) and crocodilians (Magalhães-Ribeiro and Souto, 1999). The Adamantina Formation has yielded the only snake remains from the Cretaceous of Brazil.…”