Description
Authentic Sowerbyceras tortisulcatum Ammonite Fossil from Morocco
This listing offers a Sowerbyceras tortisulcatum ammonite fossil, a remarkable relic from the Oxfordian stage of the Upper Jurassic, dating back approximately 160 million years. Discovered in Morocco, this ammonite represents one of the classic genera that flourished during the Jurassic seas, preserved with striking morphological detail that showcases the unique coiling and ribbing typical of the species.
The specimen has been carefully selected for both scientific interest and collector value. To ensure complete accuracy for scale, the fossil is photographed with a 1 cm cube reference, so you can fully appreciate its size and structure. This is the exact ammonite fossil you will receive, making it a one-of-a-kind acquisition for fossil enthusiasts, collectors, or as an educational reference piece. As with all our specimens, it comes with a Certificate of Authenticity guaranteeing it is 100% genuine.
Geological Context – Oxfordian, Upper Jurassic
The Oxfordian stage (c. 163.5–157.3 million years ago) marks the beginning of the Late Jurassic, a time of significant diversification of marine life. In the shallow seas of what is now Morocco, ammonites such as Sowerbyceras tortisulcatum thrived alongside marine reptiles, bivalves, and echinoids. These warm, nutrient-rich seas provided the ideal depositional environment for ammonite preservation, often in limestone and marl sediments that later hardened to entomb these remarkable fossils.
Ammonites are not only prized for their natural beauty but also play a crucial role in biostratigraphy, allowing geologists to precisely date rock layers across the world. The Oxfordian is particularly well-known for its ammonite diversity, and Sowerbyceras species are important reference fossils for this time interval.
Scientific Classification
- Genus: Sowerbyceras
- Species: Sowerbyceras tortisulcatum
- Family: Sowerbyceratidae
- Superfamily: Perisphinctoidea
- Order: Ammonitida
- Geological Stage: Oxfordian, Upper Jurassic
- Locality: Morocco
Distinctive Morphological Features
Sowerbyceras tortisulcatum is recognised for its elegant coiling and ribbed shell, which reflect both its evolutionary adaptations and its role as a biostratigraphic marker. Notable features of this species include:
- Planispiral coiling, forming a disc-like shell with tightly overlapping whorls.
- Regular ribbing along the flanks, often bifurcating towards the outer edge, giving a striking ornamental appearance.
- A compressed whorl section, making the fossil display especially appealing in profile.
- A combination of strength and delicacy in the ribbing pattern, which helps distinguish Sowerbyceras from closely related ammonites.
These traits highlight the ammonite’s functional morphology, which allowed it to maintain buoyancy while navigating the Jurassic seas.
Paleoecological Significance
As an active nektonic predator, Sowerbyceras tortisulcatum played a key role in the Oxfordian marine ecosystem. Its streamlined shell and buoyancy chambers allowed it to move freely through the water column, preying on small crustaceans, molluscs, and juvenile fish. This ammonite shared its environment with marine reptiles such as plesiosaurs and ichthyosaurs, as well as other cephalopods.
The presence of these ammonites in Moroccan deposits reflects the widespread distribution of the genus, which made them highly successful and adaptable within Jurassic seas. Each fossil provides a snapshot of a thriving ocean ecosystem frozen in time.
Collector and Display Value
This Sowerbyceras tortisulcatum ammonite fossil is an excellent specimen for collectors, academics, and enthusiasts alike. Its aesthetic ribbing, evolutionary importance, and well-documented geological age make it a versatile addition to any fossil collection. Beyond its scientific relevance, its natural symmetry and detailed shell structure make it an attractive display piece for homes, offices, or educational settings.
Because the fossil shown in the photographs is the exact specimen you will receive, you can buy with confidence knowing you are securing a unique and authentic ammonite. Combined with its Certificate of Authenticity, this piece offers both historical significance and natural beauty.
Key Details
- Fossil Type: Ammonite
- Species: Sowerbyceras tortisulcatum
- Age: Oxfordian, Upper Jurassic (c. 160 million years old)
- Origin: Morocco
- Distinctive ribbing and compressed shell morphology
- Supplied with a Certificate of Authenticity
- Photographed with 1 cm scale cube for accurate sizing
This rare Sowerbyceras tortisulcatum ammonite fossil is an extraordinary find from the Oxfordian stage, combining geological significance, aesthetic value, and scientific importance in one unique specimen.


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