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Full-Text Articles in Physical Sciences and Mathematics
Utilizing Phylogenetic And Geochemical Techniques To Examine Echinoderms Through Time, Maggie Ryan Limbeck
Utilizing Phylogenetic And Geochemical Techniques To Examine Echinoderms Through Time, Maggie Ryan Limbeck
Doctoral Dissertations
Understanding biotic changes through Earth’s history has been the goal of paleobiology since the inception of the field. Advances in science and technology have progressed allowing us to reassess old questions and new questions that could have not been addressed without these new methods. Echinoderms (sea stars, sea urchins, etc.) appear in the fossil record during the early Cambrian and are still abundant in marine ecosystems today. This persistence through time has made echinoderms model organisms to answer questions about Earth’s past and present. Despite this role as a model organism there are many questions that remain with respect to …
The Homology And Phylogeny Of The Diploporita (Blastozoa: Echinodermata), Sarah Lynne Sheffield
The Homology And Phylogeny Of The Diploporita (Blastozoa: Echinodermata), Sarah Lynne Sheffield
Doctoral Dissertations
Evolutionary relationships of extinct echinoderms are poorly understood, especially within stem-bearing blastozoans, a large group of echinoderms with unique respiratory structures and feeding brachioles. They were highly experimental in their body plans and very unlike echinoderms today (e.g., sea urchins). Many of the blastozoan subgroups recognized in recent classifications do not represent clades (natural associations of organisms derived from a single ancestor); they are either grades of organization or groups united by superficially similar features. Consequently, these ‘traditional’ groupings cannot be used to analyze evolutionary questions, such as biogeography or rates of evolution. This problem is highlighted within the diploporitan …