LK Ammonite Cleoniceras IF-MA-16-005

Cleoniceras besairiei
Lower Cretaceous (Albian)
Mahajanga Basin
Madagascar

Here is an outstanding example of C. besairiei with the original shell removed to reveal a really detailed suture pattern.  This specimen is a complete phragmocone with a small portion of the living chamber.   Most examples from these localities are sanded and polished to such an extent that the original aragonite shell is removed and often the detail of the suture pattern is lost.  Careful preparation however can preserve the original complexity of the sutures as well as the lateral ribbing characteristic of the species.  The ammonite is 11.5 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.