Abstract

Morphological and molecular studies have inferred multiple hypotheses for the phylogenetic relationships of Testudines. The hypothesis that Testudines are the only extant anapsid amniotes and the sister taxon of diapsid amniotes is corroborated by morphological studies, while the hypothesis that Testudines are diapsid amniotes is corroborated by more recent molecular and morphological studies. In this study, the placement of Testudines is tested using the full length cDNA sequence of the polypeptide hormone precursor proopiomelanocortin (POMC). Because only extant taxa have been used, the hypotheses being tested are limited to the following (1) Testudines as the sister taxon of Archosauria, (2) Testudines included in Archosauria and the sister taxon of Crocodilia, (3) Testudines as the sister taxon of Lepidosauria, (4) Testudines as the sister taxon of Sauria, and (5) Testudines as the sister taxon of a monophyletic Mammalia–Sauria clade. Neither Maximum likelihood, Bayesian, or maximum parsimony analyses are able to falsify the hypothesis of (Archosauria (Lepidosauria, Testudines)) and as such is the preferred inference from the POMC data. Zusammenfassung Morphologische und molekluargenetische Untersuchungen haben zu verschiedenen Hypothesen uber die Verwandtschaftsverhaltnisse der Testudines gefuhrt. Die Hypothese, dass Testudines die einzigen noch lebenden anapsiden Amnioten und das Schwestertaxon der diapsiden Amnioten sind, wird durch morphologische Untersuchungen bekraftigt, wahrend neuere morphologische und molekulargenetische Studien eher die Hypothese stutzen, dass Testudines diapside Amnioten sind. In dieser Studie untersuchen wir die Stellung der Testudines mittels vollstandiger cDNA-Sequenzen des polypeptiden Prohormons Proopiomelanocortin (POMC). Da nur lebende Taxa verwendet werden, konnen nur folgende Hypothesen getestet werden: 1) Testudines ist das Schwestertaxon der Archosauria, 2) Testudines sind in Archosauria enthalten und somit das Schwestertaxon der Crocodilia, 3) Testudines sind das Schwestertaxon der Lepidosauria, 4) Testudines sind das Schwestertaxon der Sauria und 5) Testudines sind das Schwestertaxon einer monophyletischen Mammalia–Sauria Gruppe. Weder Maximum-Likelihood, Bayesian oder Maximale Parsimony Analysen waren in der Lage, die Hypothese (Archosauria (Lepidosauria, Testudines)) zu falsifizieren, sodass diese die bevorzugte Folgerung aus den POMC Daten darstellt.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.