Convergent Evolution in Tooth Morphology of Filter Feeding Lamniform Sharks

• Main Author: Mitchell, Michaela Grace
• Format: Text
• Language: unknown
• Published: CORE Scholar 2016
• Subjects: Department of Earth and Environmental Sciences; Paleontology; Morphology; Evolution and Development; Earth Sciences; Environmental Sciences; Physical Sciences and Mathematics; Cetorhinus maximus
• Online Access: https://corescholar.libraries.wright.edu/etd_all/1652; https://corescholar.libraries.wright.edu/cgi/viewcontent.cgi?article=2792&context=etd_all

The basking shark (Cetorhinus maximus) and megamouth shark (Megachasma pelagios) are two species of filter feeding sharks, both belonging to the order Lamniformes. There are two conflicting hypotheses regarding the origins of filter feeding in Lamniform sharks; that there is a single origin of filter feeding within Lamniformes, or conversely, the filter feeding adaptations have been developed independently due to different ancestral conditions. Evidence obtained from several studies strongly supports the latter hypothesis. Because evidence suggests that C. maximus and M. pelagios have developed their filter feeding adaptations independently, we expect to see convergent evolution taking place within these two lineages. Geometric morphometric analyses were performed on fossil and Recent teeth of megamouth and basking sharks to determine if there is commonality among tooth shape. The results of the analyses support independently derived filter feeding morphologies and convergent evolution within these two lineages.