Free-Standing Goniatite Specimen, Morocco, 5cms/36g

A sold as seen, free-standing, polished Gonioclymenia specimen, an ancient marine ammonoid cephalopod commonly called a Goniatite - an early ancestor of modern squids, octopuses, and ammonites.

It comes from the Late Devonian Period (360-370 million years ago) and originated from the Erfoud region, Morocco.  It has been quarried from massive, dense limestone beds, the rock then sliced and polished to reveal the internal chambering of the Goniatite, filled with natural calcite or quartz mineralisation.

This Goniatite began life as a swimming marine creature that lived in a warm, shallow sea that covered what is now the Sahara Desert. When it died, and sank to the sea floor, layers of sediment covered it, protecting it from scavengers and destructive waves and over millions of years, heavy layers of sediment pressed down on the shell. Then groundwater, rich in minerals seeped into the hollow chambers (camerae) and the original shell material dissolved. Dissolved minerals, mainly calcite and quartz, crystallised inside the empty spaces, creating the beautiful white and grey patterns visible today. The surrounding mud hardened into a dense, dark grey or black limestone matrix, locking the fossil inside a solid stone vault.

Goniatites survived for over 140 million years, but their story ended abruptly around 252 million years ago during the Permian Mass Extinction ("The Great Dying"). A colossal wave of volcanic eruptions,  in what is now Siberia,  triggered catastrophic global warming, ocean acidification, and severe ocean deoxygenation and wiped out approximately 96% of all marine life, including the Goniatite lineage.   
      
Specimen Specific Information:

This specimen weighs 36g, measuring approx. 5cms x 4cms x 1cm and displays;
    • Septa (Chamber Walls): these are the wavy, cream-coloured lines curling out from the centre.
    • Suture Lines: Where the wavy internal walls touch the outer shell, they create patterns called sutures. 
    • Living Chamber (Body Chamber): The large, solid dark-grey/black region at the wide opening of the shell is where the creature lived. Unlike the back chambers, which were sealed off for buoyancy, this front area stayed open and filled up completely with dark lime-mud after the creature died.
    • Protoconch (The Core): At the  centre of the spiral on both sides, there is a tiny, solid grey dot. That is the protoconch, the original embryonic shell the creature possessed when it first hatched 360 million years ago.
    • Asymmetrical Polishing: The artisan who prepared this specimen selectively removed the rough outer matrix. On one side, the curved chamber lines are highly defined and sharp. On the other side, the polishing cut deeper or at a slightly different angle, revealing a broader, more mottled pattern of the crystalline calcite replacement.
    • Calcite Veil: The faint, misty white lines cutting randomly across the dark body chamber aren't part of the creature but healed stress fractures. When tectonic activity squeezed the limestone beds millions of years after burial, the rock cracked slightly, and calcium-rich water filled the gaps to create micro-veins of white calcite.