Let me join as one of the numbers
Acient DF that would be cool to see:
"Dragons":
T-Rex
Utharaptor
Ankylosaurus
Pachycephalosaurus
Stegosaurus
Triceratops
Therizinosaurus
Other:
Ground Sloth
Smilodon
Cave Bear
Entelodonts
Dire Wolf
Terror Bird
Woolly Rhinoceros
Cave Beard / Entelodonts / Dire Wolves wouldn't be interesting IMO. Cave Bear's just big, but not as big as any dinosaur so far. Dire Wolves are just stockier Grey Wolves and Hell Pigs are way too abstract. Wouldn't imagine any of them make it. IMO, the only other mammal we'll see will be a Smilodon.
I got my fingers crossed for Tyrannosaurus Rex, Ankylosaurus, Smilodon and Triceratops as the four remaining Tobi Roppo. They'd be Hella interesting, albeit Rex is a little redundant with two other theropods around.