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Re: Fossil bird egg from Upper Cretaceous of Brazil (free pdf)



Ben Creisler
bcreisler@gmail.com


The pdf is now free in open access at the link.

On Wed, Jun 11, 2014 at 9:10 AM, Ben Creisler <bcreisler@gmail.com> wrote:
> Ben Creisler
> bcreisler@gmail.com
>
> A new online paper:
>
> Júlio Cesar. de A. Marsola, Gerald Grellet-Tinner, Felipe C.
> Montefeltro, Juliana M. Sayão, Annie Schmaltz Hsiou & Max C. Langer
> (2014)
> The first fossil avian egg from Brazil.
> Alcheringa (advance online publication)
> DOI:10.1080/03115518.2014.926449
> http://www.tandfonline.com/doi/full/10.1080/03115518.2014.926449#.U5h8hfldXTo
>
> In contrast to the rich record of eggs from non-avian dinosaurs,
> complete eggs attributable to Mesozoic birds are relatively scarce.
> Nevertheless, several well-preserved specimens have been discovered
> over the last three decades revealing functional and phylogenetic
> characters that shed light on the breeding strategies of extinct
> birds. Here we report the first fossil avian egg from Brazil, which
> was discovered in Upper Cretaceous strata of São Paulo in the
> southeastern part of the country. The taxonomic identity and
> structural features of the biomineralized tissues were determined
> using a combination of Scanning Electron Microscopy, Wave Dispersion
> Energy analyses and Computed Tomography. These show that the
> 125.5-μm-thick shell of the 31.4 × 19.5 mm egg incorporates three
> structural layers of similar thickness with both prismatic and
> aprismatic boundaries. Close similarity between the Brazilian bird egg
> and those of enantiornithines from the Upper Cretaceous Bajo de la
> Carpa Formation (Río Colorado Subgroup) of Argentina advocates
> affinity with basal Ornithothoraces. Furthermore, coherency of their
> depositional contexts might imply a compatible preference for breeding
> and nesting environments.