Please use this identifier to cite or link to this item: https://hdl.handle.net/2440/134280
Type: Thesis
Title: The Evolution of Sea Turtles
Author: Chatterji, Ray
Issue Date: 2021
School/Discipline: School of Biological Sciences
Abstract: Chelonioidea (sea turtles) are a group where available morphological evidence for crown group relationships are incongruent with those established using molecular data. However, morphological surveys of crown group taxa tend to focus on a recurring subset of the extant species. The Australian flatback sea turtle, Natator depressus, is often excluded from comparisons and it is the most poorly known of the seven extant species of Chelonioidea. Previous descriptions of its skull morphology are limited and conflict. Here we describe two skulls of adult N. depressus and re-examine the phylogenetic relationships according to morphological character data. Using X-ray micro Computed Tomography we describe internal structures of the braincase and identify new phylogenetically informative characters not previously reported. Phylogenetic analysis using a Bayesian approach strongly supports a sister group relationship between Chelonia mydas and N. depressus, a topology which wasn’t supported by previous analyses of morphological data but one that matches the topology supported by analysis of molecular data. Our results highlight the general need to sample the morphological anatomy of crown group taxa more thoroughly before concluding that morphological and molecular evidence is incongruous.
Advisor: Jones, Marc
Hutchinson, Mark
Sanders, Kate
Dissertation Note: Thesis (Ph.D.) -- University of Adelaide, School of Biological Sciences, 2021
Keywords: Sea turtles
Chelonioidea
Cheloniidae
Dermochelyidae
Protostegidae
Skull
Morphology
Geometric Morphometrics
Tip-dating
Provenance: This electronic version is made publicly available by the University of Adelaide in accordance with its open access policy for student theses. Copyright in this thesis remains with the author. This thesis may incorporate third party material which has been used by the author pursuant to Fair Dealing exceptions. If you are the owner of any included third party copyright material you wish to be removed from this electronic version, please complete the take down form located at: http://www.adelaide.edu.au/legals
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