MADAGASCAN CLEONICERAS SUTURED AMMONITES
Complexly sutured and mineral infilled chambered Cleoniceras fossil ammonites, the extinct molluscs were a class of cephalopoda part of the ammonoidea subclass, similar to modern-day squids, cuttlefish and octopi all of the Mollusca phylum. Some Madagascan fossil Cleoniceras shells exhibit fine divisions of the extinct cephalopods septa, chamber walls or divisions. Naturally formed from chitin secreted by the cephalopod in life, building its home. These lighter and darker coloured wavy chamber septa can be seen against honey and treacle colour camerae (chambers) which is a calcite mineral infill formed post-death. The sutures are found at the point of divisions of growth, as the ammonite added each new camerae and septa wall a larger suture stage developed.
The frilly sutures were the points of attachment of the septa, separating each chamber of the mollusc.In the last chamber, the soft body of the mollusc dwelled. These septa sutures were attached to the inner shell and have left the patterning which is a remarkable event in the natural history of the cephalopod.
Once polished the attractive markings become apparent if the fossil has preserved well, many times this is not the case. Beautiful examples are rare, many more ammonites are not so attractively marked. The sutured chambers are filled with minerals, often quartz, calcites and jaspers. Which are all semi-precious minerals of the mineral kingdom. The fossilised shell itself has a good three dimensional or inflated shape and is of a good size for the type. A recommended investment ammonite.
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The natural suture patterning is vivid and creates a nice contrast for the honey calcite colouration. The sutures frilly cream outlines also appear to give light and shading to the faces of the polished ammonite. A desirable Cleoniceras fossil ammonite from a classic fossil bed in Madagascar.
Genus: Cleoniceras ammonite, family Hoplitidae.
Age: Albian 100 to 113 m.y.a., Cretaceous period 135 to 65 m.y.a
Origin: N.E. Madagascar. E.Africa, South Indian Ocean