Hey,
New creatures wouldn'T be a good idea. In the moment we have a lot of creatures with no real use while they outclassed by others. I think TLC's are a way better. Just think of the Bronto, Carno, female Megaloceros, Ichtyosaurus, Megalodon, Spider, Bat etc ... on one hand cool creatures, on the other hand not even useful to play with (the Bronto animation needs really an upgrade).