Finally, the mystery of the Found TRex posters has been solved. Joe points us to this Columbia Spec interview with Jason Ruff, the artist behind the project:

“I want people to step out of their normal routine and be creative, to think a little differently,” said Jason Ruff, the 28-year-old art teacher who has posted over 1500 flyers around Columbia and elsewhere in New York the last year. “Some days I’ll get up early, get some coffee, and just walk and put up a hundred [flyers] in a day,” Ruff said. Since he brings his flyers wherever he goes, Ruff said he has also posted flyers in Barcelona and Paris while chaperoning for a school trip.

Ruff said his idea was inspired by a discovery he made on 107th Street between Amsterdam Avenue and Broadway under a trash bag. “I saw the tail and I thought it was a beautifully carved leg of a table. So I grabbed it,” Ruff said of the foot-and-a-half-long toy dinosaur.

Ruff's website is pretty amusing-- he's collected fifty responses to the poster. For instance: