Cladistians (bichirs) are yet another taxon whose phylogenetic position has been much debated since the nineteenth century. Cladistians share some unique skeletal characters with actinopterans (i.e., acipenseriformes and neopterygians), such as the ganoid scale structure or the acrodin cap on teeth, and numerous soft-tissue characters, notably in brain development (everted telencephalon) and muscles of the jaw and gill arches.