The following two Vivosaurs can improve your teams greatly.

Smilo (applied to own AZ: Attack down 10%, Defense up 90%, Evasion up 90%), found at Parchment Desert (available only after the main game).

Compso (applied to enemy AZ: Attack down 90%, Defense down 90%), found at Donation Center (200 points per fossil).

These two dinosaurs work well with many Vivosaurs. They have lower attack power than others, but their low FP cost and great Support Effects make up for this. Combine them with certain Vivosaurs, like Pachy, to use team attacks.