Decoupling of the upper jaw bones - jaw kinesis - is a distinctive feature of the ray-finned fishes, but it is not clear how the innovation is related to the extraordinary diversity of feeding behaviors and feeding ecology in this group. We address this issue in a lineage of ray-finned fishes that is well-known for its ecological and functional diversity – African rift lake cichlids. We sequenced ultraconserved elements found across the genome to generate the first well-resolved phylogeny of both the Lake Tanganyika and Lake Malawi cichlid radiations. We filmed a diverse array of over fifty cichlid species capturing live prey and quantified the extent of jaw kinesis using geometric morphometrics. Our combination of phylogenomic and kinematic data reveals a strong association between biting modes of feeding and reduced cranial kinesis, suggesting that the contrasting demands of biting and suction feeding have strongly influenced cranial evolution in both cichlid radiations.