LK Ammonite Cleoniceras IF-MA-16-001

Cleoniceras besairiei
Lower Cretaceous (Albian)
Mahajanga Basin
Madagascar

Here is an excellent example of C. besairiei with the original shell removed to expose the very fine detail of the suture pattern.  Most examples from these localities are sanded and polished to such an extent that the original geometry of the sutures is lost.  Careful preparation however can preserve the suture pattern as well as the lateral ribbing characteristic of the species.  The ammonite is 6 inches across.

Cleoniceras is a rather involute, high-whorled hoplitid from the Lower to basal Middle Albian of Europe, Madagascar, and the Transcaspian region. The shell has a generally small umbilicus, arched to acute venter, and typically at some growth stage, falcoid ribs that spring in pairs from umbilical tubercles, usually disappearing on the outer whorls.
These Lower Cretaceous ammonites are quarried commercially in Madagascar.  They are found in a hard basal glauconitic sandstone layer known as the Cleoniceras Zone.