‘Fire’ Ammonite cleoniceras 7.5cm across
Here is a gorgeous ‘Fire’ Ammonite cleoniceras, this one is especially colourful. These ammonites have a stunning red opalescent lustre. This dates back to the fossilisation process, millions of yeas ago. The mineral aragonite replaced the ammonite shell, creating these remarkable colours. The specimen here dates back to the Cretaceous period, 120 million years ago. The fiery red opalescence mean these fossils are also commonly referred to as ‘Fire Ammonites’. They occur on 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 very rarely found fossilised. As the ammonite grew larger it added new chambers to the shell, with the ammonite itself only living in the largest chamber. The name Ammonite, derives from from ‘Ammon’ the Greek God. Ammonites were plankton feeders, they had long tentacles, and they also swam upright. Altogether, there were in the region of ten thousand different species. Ammonites became extinct 65 million years ago, which was also the time the dinosaurs became extinct. The squid and octopus that swim in our seas now however, are closely related.