Some time ago. I thought a poster mentioned not being able to complete the Daily Missions because he or she didn’t have representation by all three Cenozoic Classes. I can confirm that this is still an issue. My “newbie” account is at level 42, but I do not yet have a Savannah Creature. I did try to do a Cenozoic battle with the creatures I have, but it didn’t count.
I have turned in a ticket to support.