Audoliceras Heteromorph Ammonite 204mm displaying beautiful opalescence throughout. Opalescent is characteristic of this particular fossil bed along the Volga river. The refraction of light plays a big part to the mother of pearl effect, displaying a spectrum of attractive colours. This process has been influenced not only by the natural nacre of the Audoliceras heteromorph shell, but also by the mineralisation process that takes place over millions of years to develop to this final stage. Chitin is the natural element of the shell, being the last remaining home of the once living cephalopod. The calcite cluster base of this particular specimen ammonite is very attractively coloured and sets it aside from other ammonites of this location.
Heteromorph ammonites developed rapidly in the late cretaceous, this was also a time of a great mass extinction, often referred to as the KT boundary event, it seemed just as this group were about to flourish they were extinguished forever in natural events that perhaps made seawater too anoxic or and a none temperate enviroment for their future development. For more informations on the KT boundary and ammonite evolution see more in our news feed pages, in the category fossils.