~400 BCFollowing along through Greek mythology we have the griffin. The griffin is a well known animal which is a combination part bird, part lion. I picked ~400 BC because this is when the famous tale of Prometheus Bound was likely written by Aeschyles. In the story Prometheus is bound to a rock as torture for giving fire to humanity. While he is tied to this rock he is force to endure griffins repeatedly eating out his liver. Then when they are done it is allowed to grow back again, and the whole process starts over. This isn't the first occurrence of griffins in history but it is one of the first and most prominent so I figured this would be a good place to mark it. One of the principal traits of the griffin, other than its ability to fly, is that it is often found guarding a treasure of some variety.
Mayor, Adrienne. 2000. The First Fossil Hunters: Paleontology in Greek and Roman Times. Princeton University Press, Princeton, NJ