This fossil specimen of the Cretaceous theropod Jinfengopteryx elegans contains a few small round structures that the dinosaur ate before death, probably seeds. This is rare direct evidence for diet in coelurosaurs.

Source 1:
Ji, Q., Ji, S., Lu, J., You, H., Chen, W., Liu, Y., and Liu, Y. (2005). “First avialan bird from China (Jinfengopteryx elegans gen. et sp. nov.).” Geological Bulletin of China, 24(3): 197-205.

Source 2.