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The phylogeny of extant and past geoemydids (Testudines)

Author Eduardo ASCARRUNZ
Director of thesis Walter Joyce
Co-director of thesis
Summary of thesis

Geoemydidae is a speciose clade of cryptodiran turtles with a rich fossil record spanning the Cenozoic. Although parts of the phylogenetic relationships of the extant species remain unresolved, molecular analyses have converged into an overall picture of geoemydid phylogeny. The same convergence has not been attained with analyses of morphological characters, where the results of different studies regularly show strong discrepancy with the molecular phylogeny and each other.


Morphological characters remain essential for the integration of fossil species into the phylogeny, which is crucial for a comprehensive understanding of the evolution of the group. In my thesis project, I seek to acquire high-quality morphological data, identify the causes of its (assumed) poor phylogenetic informativeness, and to apply analytical methods that would help to palliate those problems. The ultimate goal is to have a phylogeny of geoemydids that incorporates fossil and extant forms, providing a solid framework for the study of the evolution of the group.

Administrative delay for the defence