Description
Ammonite cleoniceras polished half section, 10.9cm
This Ammonite Cleoniceras polished half section measures 10.9cm across. These ammonites contain gorgeous, calcite lined interior chambers. These are only visible, when they are cut open, and sliced though the middle. This one is no exception with the ginger brown colours making a stunning contrast to the calcite crystals. The polished outer shell displays some intricate suture patterns, and some stunning opalescent colours. This specimen dates back to the Cretaceous period, 120 million years ago. They are from the North West Coast of Madagascar in the Mahajanga jungle.
Ammonites have been extinct for 65 million years. They are a form of Cephalopod, a group of marine molluscs. These first appeared in the Devonian Period, over 4oo million years ago. The soft body tissues of the ammonites, are rarely preserved, it is generally the hard outer shells that are fossilised. As the ammonite grew larger it added new chambers to the shell. The Ammonite only lived in the largest, and most recently formed chamber. The name Ammonite, derives from from ‘Ammon’ the Greek God. Ammonites were plankton feeders, with long tentacles, and swam upright. Altogether, there were in the region of four thousand different species. Ammonites became extinct 65 million years ago, at the same time as the dinosaurs. Although Ammonites themselves have long been extinct, the squid and octopus that swim in our seas now, are closely related.
