Biomechanical evidence suggests extensive eggshell thinning during incubation in the Sanagasta titanosaur dinosaurs

PeerJ

article

E. Martín Hechenleitner¹  Jeremías R. A. Taborda²  Lucas E. Fiorelli¹  Gerald Grellet-Tinner¹  Segundo R. Nuñez-Campero¹ 

[1] Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja ,(CRILAR), Provincia de La Rioja;Centro de Investigaciones en Ciencias de la Tierra ,(CICTERRA), Universidad Nacional de Córdoba;The Orcas Island Historical Museums

关键词: Sanagasta;    La Rioja;    Nesting site;    Eggs;    Finite element analyses;   

DOI  :  10.7717/peerj.4971

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

The reproduction of titanosaur dinosaurs is still a complex and debated topic. Their Late Cretaceous nesting sites are distributed worldwide and their eggs display substantial morphological variations according to the parent species. In contrast to the typical 1.3–2.0 mm thick shells common to eggs of most titanosaur species (e.g., those that nested in Auca Mahuevo, Tama, Toteşti or Boseong), the Cretaceous Sanagasta eggs of Argentina display an unusual shell thickness of up to 7.9 mm. Their oviposition was synchronous with a palaeogeothermal process, leading to the hypothesis that their extra thick eggshell was an adaptation to this particular nesting environment. Although this hypothesis has already been supported indirectly through several investigations, the mechanical implications of developing such thick shells and how this might have affected the success of hatching remains untested. Finite element analyses estimate that the breaking point of the thick-shelled Sanagasta eggs is 14–45 times higher than for other smaller and equally sized titanosaur eggs. The considerable energetic disadvantage for piping through these thick eggshells suggests that their dissolution during incubation would have been paramount for a successful hatching.

【 授权许可】

CC BY