Jurassic ballpark: A herd of friendly T-Rex invaded the Coliseum and took photos with A's fans

You expect to see certain things at the ballpark. Baseball games, obviously. Fans making great plays on foul balls. Sometimes, aggressive seagulls eager to swoop down and lay claim to leftover concession-stand fare left around after the game ends.
Generally speaking, you don't usually expect to see a herd of Tyrannosaurus Rex cavorting about in the stands, dancing and snapping photos with fans ... yet that's precisely what happened during the A's 9-1 win over the Indians at the Coliseum on Tuesday night:

As seen above, that quartet appears to have been a friendly group of dinos, eager to mingle with humans and partake in some of the baseball game experience. This isn't the first time we've seen a T-Rex at a ballpark this season, even. In fact, it's at least the third such incident. 
Here's one phenomenon we hope doesn't go extinct anytime soon.