Literaturdatenbank
Literaturdatenbank |
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Carr, J. L. (1991). Phylogenetic analysis of the neotropical turtle genus rhinoclemmys fitzinger (testudines: emydidae). Unpublished thesis PhD, Southern Illinios University, Carbondale.
Added by: Sarina Wunderlich (12 Dec 2010 20:43:01 UTC) |
| Resource type: Thesis/Dissertation BibTeX citation key: Carr1991 View all bibliographic details  |
Categories: General Keywords: Geoemydidae, Rhinoclemmys, Rhinoclemmys nasuta, Schildkröten = turtles + tortoises, Systematik = taxonomy Creators: Carr Publisher: Southern Illinios University (Carbondale) |
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| Abstract |
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The genus Rhinoclemmys is a morphologically and ecologically diverse group of nine species from the New World tropics that has conventionally been treated as a monophyletic group, hypothesized primitively to have been terrestrial and radiated in a southeasterly direction into more aquatic species. Recently, a hypothesis that the genus was polyphyletic was proposed. The need for an outgroup and the uncertainty about the monophyly of Rhinoclemmys led to examination of the entire Geoemyda complex of 11 genera. A numerical cladistic analysis of 59 morphological, 1 karyotypic, 1 isozyme, and 19 biochemical characters has resulted in a hypothesis of relationships among the Geoemyda complex genera, and a hypothesis of relationships among all Rhinoclemmys species. An independently analyzed data matrix of 26 color pattern characters for all species and subspecies of Rhinoclemmys provided confirmation of the basal branches of the Rhinoclemmys cladogram. This phylogenetic analysis led to the conclusion that the nine New World species form a monophyletic clade most closely related to Melanochelys of the Indian subcontinent. Morphometric analysis of the nine Rhinoclemmys species was conclusive in demonstrating no significant association between shell morphology and phylogeny, but neither was there a simple pattern of clustering potentially related to habitat. The most primitive extant species is highly aquatic (R. nasuta), and there is no simple ecological trend evident in the pattern of speciation that is hypothesized to have taken place. Radiation of Rhinoclemmys species is hypothesized to have been directed both north, from the Chocoan region of northwestern South America to Nuclear Central America, and south, from Nuclear Central America back toward South America and east of the Andes. The five species currently inhabiting South America are hypothesized to have originated at two separate times. Two species represent an extremely old occupation of the Choc6, while the other three appear to have dispersed across the Panamanian land bridge after its completion in the Pliocene.
Added by: Sarina Wunderlich |