Browsing by Author "Jackson, Frances Drew"

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Titanosaur reproductive biology : comparison of the Auca Mahuevo Titanosaur nesting locality (Argentina), to the Pinyes Megaloolithus nesting locality (Spain)
(Montana State University - Bozeman, College of Letters & Science, 2007) Jackson, Frances Drew; Chairperson, Graduate Committee: David Varricchio
Taphonomic and microstructural studies at the Late Cretaceous Auca Mahuevo titanosaur nesting site (Argentina) reveal significant differences in reproductive attributes compared to alleged sauropods producing Megaloolithus eggs at the Pinyes locality (Spain). Auca Mahuevo clutches contain 15-40 M. patagonicus eggs; many of the 12-14 cm eggs contain titanosaur remains. Six clutches include both normal and abnormal eggs exhibiting three types of abnormal morphology: Type I displays two normal, superimposed eggshells, while Type II and III exhibit a normal inner eggshell, with one and three overlying eggshells, respectively. Previous studies that endeavor to link egg abnormalities to dinosaur extinction lack taphonomic and rigorous statistical methods. The Pinyes locality occurs in the Tremp Formation, exposed in the Spanish Pyrenees. The overbank deposits contain clutches with 4-12 eggs; none of the 16-24 cm M. Siruguei eggs contain embryos. Although often assigned to sauropod dinosaurs, M. siruguei differs from M. patagonicus in clutch size, egg volume, shell thickness, pore density, and incubation mode; thus, taxonomic assignment to sauropods seems questionable.