In Depth
Harpymimus was a primitive member of the Ornithomimosauria and although geographically separated by several thousand miles, similar to Pelecanimimus. Harpymimus seems to display a change in dietary focus from meat to plants, something which is indicated in the upper jaw being toothless, while the only teeth remaining in the lower jaw being small and cylindrical. Rather than slicing and tearing flesh these teeth are better suited at gripping things like small animals and possibly parts of plants to be swallowed. Later members of the Ornithomimosauria would go on to lose their teeth completely with what are presumed to have been primarily if not exclusively herbivorous diets.
Further Reading
– Anatomy of Harpymimus okladnikovi Barsbold and Perle 1984 (Dinosauria; Theropoda) of Mongolia. – Y. Kobayashi & R. Barsbold – in The Carnivorous Dinosaurs, K. Carpenter – Indiana University Press: 97-126 – 2005.