Polished Half Section of the Ammonite cleoniceras 10.5cm
This is a polished half section of the Ammonite Cleoniceras, and measures 10.5cm at its widest point. When sliced open these ammonites reveal beautiful calcite filled interior chambers. On the outside some of these ammonites are naturally opalescent, this one has milky opal coloured areas. Other parts of the outer shell displays an array of elaborate suture patterns. This polished half section the ammonite cleoniceras dates back to the Cretaceous period. It is around 120 million years old. They are found near the North West Coast of Madagascar in the Mahajanga jungle.
Ammonites have been extinct for 65 million years, and were a form of Cephalopod, a group of marine molluscs. These first appeared in the Devonian Period, over 4oo million years ago. As ammonite grew larger they also added new chambers to their shell, with the actual mollusc only living in the largest and newest chamber. The name Ammonite, derives from from ‘Ammon’ the Greek God. Ammonites were plankton feeders, with long tentacles, and they also swam upright. Altogether, there were in the region of four thousand different species. Ammonites became extinct 65 million years ago. The squid, octopus and also cuttlefish that swim in our seas now however, are close relations.