In a secluded Mexican valley sometime during the early 20th century, these vaqueros (Mexican cowboys) are trying to wrangle a late-surviving Allosaurus!
This scene was of course inspired by Ray Harryhausen’s The Valley of Gwangi, which is pretty much the quintessential cowboys-versus-dinosaurs movie. I always did like Harryhausen’s stop-motion work, which to my childhood self looked like toy dinosaurs coming to life.