👉 Crossopterygian is a term used in literature and science to describe a character or object that has two aspects, one of which is a feature that is not essential for its existence. In other words, it represents an aspect that exists independently from the core characteristics of the character. For example, if "The Crossover" is a book about a protagonist who discovers their abilities are tied to a crossopterygian trait, this means the main plot revolves around the development and