Membracidae

The extraordinary treehoppers (Membracidae). Much of the extraordinary diversity in form we see in these animals is down to the ‘helmet’, which has been tweaked in to all sorts of sizes and shapes. Without the helmet, they all look very much like small cicadas. It has been discovered that this ‘helmet’ is actually an extra, wing-like appendage. See this paper (Body plan innovation in treehoppers_2011) for more information.