What is "elpistostegalia"

Elpistostegalia or Panderichthyida is an order of prehistoric lobe-finned fishes which lived during the Late Devonian period (about 385 to 374 million years ago). They represent the advanced tetrapodomorph stock, the fishes more closely related to tetrapods than the osteolepiform fishes. The earliest elpistostegalians, combining fishlike and tetrapod-like characters, are sometimes called fishapods, a phrase coined for the advanced elpistostegalian Tiktaalik.