Evolution of caudal fin ray development and caudal fin hypural diastema complex in spotted gar, teleosts, and other neopterygian fishes

Comparative anatomy and development show a hypural-diastema complex in gars and teleosts and an early role for caudal fin rays in external symmetry, so the complete complex cannot be treated as an unconditional teleost synapomorphy; descent, loss and latent parallelism remain competing histories.