Abstract
This is the first study to use both molecular and fossil data to date the divergence of taxa within the coleoid cephalopods (octopus, squid, cuttlefish). A dataset including sequences from three nuclear and three mitochondrial genes (3415 bp in total) was used to investigate the evolutionary divergences within the group. Divergence time analyses were performed using the Thorne/Kishino method of analysis which allows multiple constraints from the fossil record and permits rates of molecular evolution to vary on different branches of a phylogenetic tree. The data support a Paleozoic origin of the Orders Vampyromorpha, Octopoda and the majority of the extant higher level decapodiform taxa. These estimated divergence times are considerably older than paleontological estimates. The major lineages within the Order Octopoda were estimated to have diverged in the Mesozoic, with a radiation of many taxa around the Cretaceous/Cenozoic boundary. Higher level decapodiform phylogenetic relationships appear to have been obscured due to an ancient diversification of this group.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
More From: Cladistics : the international journal of the Willi Hennig Society
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.