Original: Saurischians ('lizard-hipped') are distinguished from the ornithischians ('bird-hipped') by retaining the ancestral configuration of bones in the hip.
Simplified: The name comes from the Greek sauros meaning 'lizard' and ischion meaning 'hip joint'. Saurischians ('lizard-hipped') and the ornithischians ('bird-hipped') have differences in the ways bones in the hip are put together.