This elrathria kingii was bought last winter in Okinawa. This is a pretty weird case because when I flipped it over, there seemed to be some weird markings. Furthermore, the trilobite did not seem to be casted from the outside, there is some cracking and no air bubbles visible. Also, there were quite a few for sale, and none looked the same. Plus, this species is so common, there shouldn't be any economic value in faking it. Any help is appreciated.
See what I mean?