Original: Tiktaalik is a genus of extinct sarcopterygian (lobe-finned "fish") from the late Devonian period, with many features akin to those of tetrapods (four-legged animals).
Simplified: Tiktaalik is a genus of extinct fish. This sarcopterygian (lobe-finned) fish from the late Devonian period, has many features akin to those of tetrapods (four-legged animals).