Dead birds as size scale

I was struck by the beautiful photograph above (1st image) of a hummingbird being used to show the size of a "monstrously big" ant that lived roughly 50 million years ago. The fossil was brought to his attention by the curator of the Denver Museum of Nature and Science and reexamined by Bruce Archibald of Canada's Simon Fraser University. The prehistoric insect - "about the body mass of a small bird" - had remained unidentified since its discovery in Wyoming. Archibald named the new North American species Titanomyrma lubei and believed it to be closely related to German giant ants. When I researched the paleoentomologist's name, I found that he had used this visually exquisite size comparison not only with a different pose, but with another hummingbird (2nd image). I can only assume that Dr. Archibald had access to entire drawers full of birds and could take his pick - drawers that are the evocative subject of Rosamond Purcell. Above (3rd image) is one of the images from her most recent book, Egg and Nest.