Fill a large stockpot halfway with water. Add the lemon wedges and place over medium heat. Bring to a boil.
Add the potatoes and corn. Allow them to cook until the potatoes are fork tender, about 15 minutes.
Add the crawfish and shrimp and let them cook until the shrimp is pink, about 5 minutes. Drain the seafood and vegetables and transfer them to an oven safe baking dish.
Add the butter, spices, lemon juice, and garlic to a saucepan over low heat. Let simmer for a couple of minutes until the butter is melted and the garlic is fragrant.
Slice the sausage and add to the baking dish. Pour the butter over the top.
Cover the baking dish tightly with foil. Allow it to bake in a 350 degree oven for 10 minutes.