Amju Games has released Amju Pet Zoo for the Macintosh. It’s available for free download from the Web site.
Dinosaurs introduce some challenge into the game — your job is either to protect your pets or feed them to the carnivores, depending on how you want to play. A Pet Zoo Shop lets you buy and sell material, and you can collect hearts in the game to unlock new areas and pick up new objects.
Amju Pet Zoo is a Universal binary, though the developer did not specify system requirements beyond that.