Tiny bird, giant ant

The above figure, from Archibald et al. (2011), shows a rufous hummingbird Selasphorus rufus alongside the newly described early Eocene giant ant Titanomyrma lubei. This fossil comes from the American Green River Formation, in present-day Wyoming. At 51 mm in length, this is one of the largest known ants.

Information and picture from Catalogue of Organisms.

This odd juxtaposition of creatures demonstrates a principle of adjectival semantics: size is relative. There's no contradiction in saying that a "tiny bird" is the same size as a "giant ant." A tiny dinosaur could be far bigger than either, and a giant virus far smaller.