The picture of the cowboy holding a dinosaur may or may not be a fake, I don't know. But I've heard rumors of such mini dinosaur or dinosaur-like
sightings for years. I have no idea if they are true, but it might be genetically feasible.
Assuming that the theory of dinosaurs evolving into birds is correct, there is also some research being done on evolving (devolving?) birds back into
dinosaurs. In fact, the paleontologist who is said to have been the inspiration for the male paleontologist in Jurassic Park, Jack Horner, is leading
some of this research and they have already had some success:
In the past few years, several groups working independently have begun to awaken the dormant dinosaur DNA present in one of the extinct
creatures' descendents: chickens, whose genome is fully sequenced. Led by Horner, the scientists hope to eventually grow a chicken that has teeth,
scales, a tail, and forelimbs. In a word, they want to build a "dinochicken," and it'll be pretty darn close to the real thing...
First, in 2005, developmental biologists John Fallon and Matt Harris at the University of Wisconsin were experimenting with mutant chicken embryos
when they noticed strange protuberances emerging from the chicken fetus's jaws. The bumps turned out to be saber-shaped teeth identical to those of
embryonic alligators.
The toothy chicken embryos were mutants — they possessed a recessive gene that kills fetuses before they're born. As a side effect (unrelated to
how it killed them), that gene was switching on another one that has lain dormant in chickens' evolutionary line for at least 70 million years: an
ancient dinosaur tooth gene. Fallon and Harris created a virus that behaved similarly to the lethal recessive gene present in the mutant chickens, but
without being deadly. When they inserted the virus into normal chicken embryos, they grew teeth.
Later, a paleontologist named Hans Larsson at McGill University found that chicken embryos' start out with tails. At a certain point in a chick's
development, a genetic switch flips and the tail goes away. Using growth hormones to try to override the stoppage, Larsson and his colleagues are
attempting to flip the switch back (though they haven't done so yet).
In the same vein, Horner believes chicken embryos can eventually be genetically manipulated to develop forearms instead of wings. "The absence of a
tail, the difference between wings and grasping forearms, and the absence of teeth are all subtle evolutionary changes on a basic dinosaur plan," he
wrote in a book he co-authored with James Gorman called "How to Build a Dinosaur" (Dutton 2009).
SOURCE: Can We Make Jurassic Park Yet?
Basically, this indicates that modern birds still have dinosaur genes that simply aren't 'switched on.' So there are at least two possibilities
that I see here:
1. It's already known that there are projects trying to create dinosaurs from chickens... maybe someone did and some have either been released or
have escaped into the wild.
2. Maybe something more natural can cause the dinosaur genes to basically be switched back on in some cases, causing dinosaurs or dinosaur-like
creatures to be born from what would normally have been bird eggs.
I find the second possibility above particularly interesting. For some reason, these genes were switched off millions of years ago. But if something
were to cause them to be switched on again, it might not go so well for humans.