Nesting and Egg Incubation in Dinosaurs: Morphological and Statistical Investigations into the Study of Eggs, Eggshells, and Nests

atmire.migration.oldid5177
dc.contributor.advisorZelenitsky, Darla Karen
dc.contributor.authorTanaka, Kohei
dc.contributor.committeememberBrinkman, Donald
dc.contributor.committeememberAnderson, Jason
dc.contributor.committeememberTherrien, François
dc.contributor.committeememberDutchak, Alexander
dc.contributor.committeememberTheodor, Jessica
dc.date.accessioned2016-12-22T20:22:49Z
dc.date.available2016-12-22T20:22:49Z
dc.date.issued2016
dc.date.submitted2016en
dc.description.abstractArchosaurs (e.g., crocodylians, dinosaurs, and birds) are the most diverse and successful terrestrial vertebrates. An understanding of the nesting strategies in both extinct (e.g., non-avian dinosaurs) and extant archosaurs (i.e., crocodylians and birds) is crucial for advancement of our knowledge on the evolution and diversification of this group. However, nesting methods and behaviors of non-avian dinosaurs are still poorly understood due to the limitations of the fossil record. In this dissertation, certain features of eggs and nests in dinosaurs (e.g., clutch size, egg mass, substrates of nests, water vapor conductance of eggs, and eggshell porosity) are compared with those of their closest living relatives (i.e., birds and crocodylians) and aspects of dinosaur nesting (i.e., nest type, incubation behavior, incubation heat source, and incubation period) are inferred and reconstructed. Findings in this dissertation suggest that nests and nesting styles among non-avian dinosaurs were diverse, and that bird-like traits were acquired throughout their evolution. Analyses of eggs and eggshell porosity indicate that more basal dinosaurs (i.e., ornithischians, sauropodomorphs, Lourinhanosaurus) completely covered their eggs with nest materials during incubation, although more derived forms (e.g., oviraptorosaurs, troodontids) used open nests, like modern birds, in which the eggs were not fully buried. The lithologies of the clutches of basal dinosaurs reveal their nests were probably incubated with external heat sources (e.g., microbial respiration, solar radiation), like those of modern crocodylians and megapode birds. Distribution and lithologies of some ornithischian and some sauropodomorph clutches show that heat from microbial respiration, in particular, was used for incubation, whereas other sauropodomorphs may have used inorganic heat sources, such as solar radiation. More derived dinosaurs (i.e., maniraptorans) had eggshell porosities and clutch lithologies that indicate their nests were partially open, indicating that these taxa brooded their eggs. Regardless of the type of nest, heat source, or incubation behavior, incubation period of most non-avian dinosaurs examined was relatively short, more comparable to that of birds than crocodylians. Major dinosaur (and archosaur) clades show diversity in their nesting and incubation, and also reveal a transition to more bird-like nesting features through evolution.en_US
dc.identifier.citationTanaka, K. (2016). Nesting and Egg Incubation in Dinosaurs: Morphological and Statistical Investigations into the Study of Eggs, Eggshells, and Nests (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/27073en_US
dc.identifier.doihttp://dx.doi.org/10.11575/PRISM/27073
dc.identifier.urihttp://hdl.handle.net/11023/3505
dc.language.isoeng
dc.publisher.facultyGraduate Studies
dc.publisher.institutionUniversity of Calgaryen
dc.publisher.placeCalgaryen
dc.rightsUniversity of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.
dc.subjectPaleontology
dc.subject.classificationArchosauren_US
dc.subject.classificationDinosauren_US
dc.subject.classificationEggen_US
dc.subject.classificationIncubationen_US
dc.subject.classificationNesten_US
dc.subject.classificationNestingen_US
dc.titleNesting and Egg Incubation in Dinosaurs: Morphological and Statistical Investigations into the Study of Eggs, Eggshells, and Nests
dc.typedoctoral thesis
thesis.degree.disciplineGeology and Geophysics
thesis.degree.grantorUniversity of Calgary
thesis.degree.nameDoctor of Philosophy (PhD)
ucalgary.item.requestcopytrue
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