Matching Pair of Ammonite cleoniceras 10.9cm at widest point
This Matching Pair of Ammonite cleoniceras is superb When cut in half, these Cleoniseras Ammonites reveal, their intricate interior chambers. Once polished, some of the chambers reveal gorgeous calcite crystals. The outer shell of these beautiful ammonites display flashes of iridescent colour, and glimpses of red opalescence. This was formed when the mineral aragonite replaced the ammonite shell. These fossils date back to the Cretaceous period 120 million years ago. They are from Madagascar in an area of the Mahajanga jungle on the north west coast.
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 very rarely found fossilised. It is generally the tougher shells that have been preserved. 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.