The terminology of fossil plants is in places a little confusing. In the discipline's 200+ year history, certain concepts have become entrenched, even though improved understanding has threatened the foundations upon which they're based. The traditional definition of microphylls and megaphylls will be employed in this article for simplicity; their merits will be discussed later. Traditionally, a microphyll is "an appendage supplied by a single, unbranched vein". Despite their name, microphylls a… (More on Microphyll)