All I really remember was at the end a guy got put into a pit and these little almost pterodactyl looking blood sucking monsters came out to try to kill him. I can see the pit he was in and the little monsters in my mind but just cannot remember what this was.
It's been a long time since I've watched this, but something like this happens in
At the Earth's Core (1976).
Doug McClure and
Peter Cushing travel to the Earth's core, where they meet
Caroline Munro and a primitive civilization enslaved by telepathic pterodactyls.
Andrew has a review of it
here, where you can see some screencaps.