Macey Tycoliz

Document Type

Honors Thesis


Geckos of genus Gonatodes are common to areas across Central America, South America, and the Caribbean. Recent studies have shown new Gonatodes species continue to be recognized. Although significant to the field of biology, new species are typically described with scarce information about their basic biology, detailed aspects of their anatomy, and systematic relationships. Without this information it is not possible to infer phylogenetic relationships or to study character evolution in the context of phylogenetic trees. Advancements in DNA sequencing have been used to identify the pattern of evolution in many species. Although this approach may seem effective, there are several factors that contribute to its inaccuracy. A separate method, which has shown to improve pre-existing phylogenetic trees, utilizes osteological features. The aim of this study is to provide evidence that an osteological approach is useful in the study of phylogenetics. To achieve this objective, computerized tomography (CT) scans of preserved specimens Gonatodes ceciliae, Gonatodes daudini, and Gonatodes machelae were obtained. With the use of Drishti software, individual scans were segmented resulting in three-dimensional images of the cranial bones of these specimens of Gonatodes. Specific boney elements were colored for each three-dimensional scan via MeshLab. Similar characters among G. ceciliae, G. daudini and G. machelae were identified and compared. The evaluation of bony characters provided evidence that an osteological approach is potentially useful in the improvement of pre-existing phylogenetic trees.

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