Rare Fossil Ammonite Olcostephanus Valanginian Cretaceous Agadir Morocco COA

Description

Rare Fossil Ammonite – Olcostephanus from Morocco

This listing is for a rare fossil ammonite of the genus Olcostephanus, dating to the Valanginian stage of the Early Cretaceous (approximately 139–132 million years ago). Discovered near Agadir, Morocco, this specimen represents one of the classic ammonite types from this important geological interval. The fossil has been carefully selected for its preservation, form, and clarity of features, making it both a valuable collector’s item and an excellent educational piece. The photographs provided show the exact specimen you will receive, and the ammonite comes complete with a Certificate of Authenticity.

Geological Context – Valanginian, Early Cretaceous

The Valanginian stage forms part of the Lower Cretaceous and is a key interval in Earth’s history. During this time, extensive shallow seas covered much of what is now North Africa, including the Moroccan region. These marine environments were highly favourable for the preservation of ammonites and other marine invertebrates, leaving behind rich fossil beds that are studied by palaeontologists worldwide.

Ammonites such as Olcostephanus are regarded as important biostratigraphic index fossils, helping to define and correlate Valanginian rock layers across continents. Specimens from Morocco often display excellent preservation, revealing structural details of the shell that make them highly desirable to collectors.

Scientific Classification

• Kingdom: Animalia
• Phylum: Mollusca
• Class: Cephalopoda
• Order: Ammonitida
• Superfamily: Perisphinctoidea
• Family: Olcostephanidae
• Genus: Olcostephanus

This classification places the ammonite within the family Olcostephanidae, a group known for their relatively involute coiling and distinct ribbing, which are hallmarks of Early Cretaceous ammonites.

Morphological Features

The fossil shows the typical characteristics of Olcostephanus:

• Planispiral coiling, with the whorls tightly wound.
• Strong, radial ribbing across the shell surface, giving a distinctive textured appearance.
• Ribs often bifurcate from the umbilical edge and extend toward the venter, enhancing both structural strength and visual appeal.
• Moderate umbilicus, a common feature in this genus.
• In some examples, the ventral region shows subtle strengthening ribs or slight keel-like features, adaptations that aided hydrodynamics.

These features make Olcostephanus highly recognisable and distinguishable from other ammonites of the same period.

Palaeoecology and Lifestyle

Like other ammonites, Olcostephanus was a nektonic carnivore, moving actively in the Valanginian seas. Its chambered shell provided buoyancy control, while the ribbing strengthened the shell against both predators and water pressure. Ammonites are thought to have preyed on smaller marine organisms such as planktonic crustaceans and juvenile fish.

The Moroccan seas during the Valanginian hosted a diverse ecosystem of ammonites, belemnites, bivalves, echinoids, and marine reptiles, creating a thriving environment where ammonites played a crucial role in the marine food web.

Collecting and Display Value

This specimen of Olcostephanus is a fine example of a Cretaceous ammonite fossil from Morocco, prized for its distinctive ribbing and robust preservation. Its natural detail makes it suitable for display in a private fossil collection, a museum setting, or as a conversation piece in any educational or decorative environment. It also serves as a tangible connection to the Early Cretaceous seas and the evolutionary history of cephalopods.

Provenance and Guarantee

• Genus: Olcostephanus
• Age: Early Cretaceous, Valanginian (approx. 139–132 million years old)
• Formation/Region: Agadir area, Morocco
• Geological Context: Marine deposits of the Valanginian

All our specimens are 100% genuine fossils, each accompanied by a Certificate of Authenticity. The ammonite you see pictured is the exact specimen you will receive, ensuring authenticity and transparency.

This rare Olcostephanus ammonite from Agadir, Morocco is both a scientifically important fossil and a striking natural artifact, making it an exceptional addition to any collection.