Really hilarious Brontosaurus (now officially called Apatosaurus) on this old panel cartoon. The smile on his face is just precious. The Pteranodon, on the other side, looks pretty grumpy.
Besides the two headed dragon beast, the planet Mongo's obviously supported some nasty Stegosaur-like creatures that had some peculiar fangs in their jaws. Lucky for Flash Gordon and his pals, the animals seem to be very slow and clumsy, so the brave hero can cut them down with his sabre before they can do any harm.
Wonder Woman appears to be lassoing a dinosaur-looking creature... or is it a dragon? Or is it a man in a rubber suit? A stone age woman coming running to help her or the "dinosaur pet"?
Instead of having her for a lunch, the dirty old T. rex seems to be more interested in ripping off her clothes. Precision at work!
For a change, here is my Supergirl vs. Pteranodon flock drawing from 2005: