%0 Journal Article %T The mitochondrial phylogeny of an ancient lineage of ray-finned fishes (Polypteridae) with implications for the evolution of body elongation, pelvic fin loss, and craniofacial morphology in Osteichthyes %A Dai Suzuki %A Matthew C Brandley %A Masayoshi Tokita %J BMC Evolutionary Biology %D 2010 %I BioMed Central %R 10.1186/1471-2148-10-21 %X Our molecular phylogeny reveals 1) a basal divergence between Erpetoichthys and Polypterus, 2) polyphyly of P. endlicheri and P. palmas, and thus 3) the current taxonomy of Polypteridae masks its underlying genetic diversity. Ancestral state reconstructions suggest that pelvic fins were lost independently in Erpetoichthys, and unambiguously estimate multiple independent derivations of body elongation and shortening. Our mitochondrial phylogeny suggested species that have lower jaw protrusion and up-righted orbit are closely related to each other, indicating a single transformation of craniofacial morphology.The mitochondrial phylogeny of polypterid fish provides a strongly-supported phylogenetic framework for future comparative evolutionary, physiological, ecological, and genetic analyses. Indeed, ancestral reconstruction and geometric morphometric analyses revealed that the patterns of morphological evolution in Polypteridae are similar to those seen in other osteichthyans, thus implying the underlying genetic and developmental mechanisms responsible for those patterns were established early in the evolutionary history of Osteichthyes. We propose developmental and genetic mechanisms to be tested under the light of this new phylogenetic framework.Osteichthyans (bony fish and tetrapods; Fig. 1) have evolved remarkably diverse body plans since their initial radiation in the Late Silurian ~420 Mya [1,2]. It is therefore not surprising that most major extant lineages have been the subject of extensive evolutionary biology research. As a result, we know much about the evolutionary history and patterns of morphological evolution in osteichthyans, most notably teleost fish and tetrapods (amphibians, reptiles, and mammals). In the age of genomics and advanced molecular techniques, knowledge of these relationships and patterns has proven useful in uncovering the developmental and genetic mechanisms responsible for morphological diversity [e.g., [3-9]].However, the same canno %U http://www.biomedcentral.com/1471-2148/10/21