ornithomimosaur

/AO1 R N AH0 T OW0 M AH0 M AH0 S AO1 R/
noun
  1. 1

    Any of several theropod dinosaurs, of the superfamily Ornithomimosauria, that bore a superficial resemblance to modern ostriches

Source: https://en.wiktionary.org/wiki/ornithomimosaur