Iridescent Cleoniceras Ammonite with Attached Bivalve

Description: This fine ammonite is Cleoniceras from Madagascar which has much of the original iridescent shell present. This is a consequence of light passing through the various layers of aragonite and conchiolin deposited by the ammonite in life. The lack of acidity in the depositional environment allowed them to be preserved as you see it here. Notice the play of colors when the viewer’s aspect changes. The most unusual feature of this specimen is that there is also a preserved 8 mm x 6 mm bivalve attached to the shell. It is not known whether this was a post-mortem attachment or not, but it renders an already fine specimen all the more interesting.