honestly, this isn't as o/t as it may at first appear. i was once (briefly) an archaeologist and have always found design inspiration in the ancient world. i was just reminded how drawn i am to the motifs on british celtic coins, in particular the horses. many of these coins were made in imitation of greek coins (the gold stater of philip II of macedon, in particular):
over time the designs evolved further and further from the original, becoming progresively more abstract:
you can still see the chariot wheel in both my examples. the cross/ear of corn type pattern on the obverse is derived from philip's laurel wreath (and ears?).
i was searching for a book with plenty of illustrations to use as a design reference when i came across the ultimate resource; the celtic coin index online. there are thousands of images, you can browse by tribe and every image is accompanied by comprehensive information on its provenance, composition etc.
love it :D