xii, 179 leaves : ill. (chiefly col.) ; 28 cm. "September 26, 2012."Physical, chemical, and osteo-histological signatures in fossils can be extremely
informative about organismal life history and ecological characteristics, yet these
signatures have not yet been exploited to their fullest potential. Tools such as
microscopy and mass spectrometry have the potential to address issues and questions in
vertebrate paleontology that have, until now, remained elusive. First, this dissertation
begins with traditional methods of anatomy and systematics with the addition of
improved sampling and visualization of a historic specimen, Macrerpeton huxleyi. The
edopoid temnospondyl Macrerpeton huxleyi is redescribed on the basis of new peels of
the holotype. Phylogenetic analysis recovers Macrerpeton as the sister taxon of
Cochleosaurus within the edopoid clade Macrerpetidae (formerly Cochleosauridae).
Histological signatures in fossil bone can be used to reconstruct information about
extinct organisms, such as genome size. Nonetheless, intra-skeletal osteocyte lacunae size
variation, which could cause error in genome size estimation, has remained unexplored.
While there is variance in the sizes of these bone structures over the skeleton of modern
tetrapods, this variation is not necessarily causing any issues with genome size estimate;
instead, the actual methods of estimation create a wide range of potential values that
these methods are not able to answer certain genetic questions at a fine scale.Examining the carbon and oxygen isotopes in tooth enamel represents a quantitative method for discerning the paleoenvironments and paleoecology of fossil fauna. The Chinchilla Local Fauna from southeastern Queensland is a diverse assemblage of terrestrial Pliocene vertebrates from the Chinchilla Sand Formation. Isotopic analysis results from Chinchilla show that there were distinct dietary niches within the large marsupial vertebrate community. This study suggests that southeastern Queensland hosted a mosaic of tropical forests, wetlands and grasslands during the Pliocene. A review of the uses of biogenic materials in eggshells for stable isotope analysis is also provided. Stable isotope analysis is also used to determine paleoenvironments and paleoecology of dinosaurs during the Late Cretaceous in Mongolia. This study, which is the first to utilize stable isotope geochemistry on Mesozoic fossil tooth enamel from central Asia, documents that the environment was arid, but more importantly that dinosaur remains, such as eggshells, can be used for this type of study. These objectives are united by a need to use quantitative measurements to more accurately reconstruct vertebrate traits throughout earth history.Richard Gilder Graduate School at the American Museum of Natural History
