I recently discovered the work of illustrator Justin White, AKA Jublin. This "time travel poster" is a good representation of his work. I never get tired of cowboys riding dinosaurs!
He's done a few other pieces featuring dinosaurs, including these unfortunate tyrannosaurs.
He's had quite a few designs chosen for print at Threadless. Check them out here.
Want to see more Threadless designs I've featured here? Easy-peasy.
Check out this post, this one, this one, this one, and this one.