Do you know what dimidiation is? Unless you happen to be a scholar of medieval heraldry, you probably don’t. It’s an older method of combining two or more coats of arms into a single shield to denote a union of, say, two families. In dimidiation, the two coats of arms would be cut down the middle, so you might end up with a shield featuring a griffin’s head stuck to a horse’s rear. Later on, it became more common to simply feature the two coats of arms side by side (a practice known as impalement), which is less confusing and more aesthetically pleasing, but also less funny.