In a world that's constantly creating new kinds of comfort food, pizza remains a constant classic. While the dish we know today has its roots in 17th-century Naples, it wasn't until the late 19th century that it landed in the U.S. Needless to say, we haven't stopped doling out cheesy, greasy slices -- and inventing new ways to do so -- in the years since.

The thing about pizza is that it's far more diverse than we give it credit for. While at its core, it's always some kind of tantalizing combo of bread and toppings, it's the way we stack these toppings (and what we stack them on) that gives each style of pizza its unique allure. Over the years, local communities have curated their own takes on the dish. Some, like New York and Chicago deep dish, have withstood the test of time. Others, however, have been slightly less lucky.

While it's a stretch to say that the following styles of pizza are extinct, they've definitely dipped in popularity in recent times. Food trends come and go -- and there's always every chance that they'll resurface again in the future. But for now, it feels like these pizza styles are on their way out.