Please note that the following Mayhem Tournaments only gave the Packs as rewards, the dino unlocks were not given as rewards:

Common Mayhem -  May 27th - May 28th, 2022 - Bageherpeton Pack
Rare Mayhem - May 28th - May 29th - Edaphosaurus Pack
Super Rare Mayhem - May 29th - May 30th - Bageherpeton Pack
Legendary Mayhem - May 30th - May 31st - Edaphosaurus Pack