Description
Rare Hecticoceras (Brightia) brightii Ammonite Fossil
This listing offers a rare Hecticoceras (Brightia) brightii ammonite fossil from the Upper Callovian stage of the Jurassic period, approximately 164 – 161 million years old, found in the world-renowned fossil beds of Ryazan, Russia. This ammonite represents one of the most scientifically significant and visually appealing cephalopods from the Jurassic seas, prized by collectors for its rarity, distinctive morphology, and well-preserved detail.
The fossil pictured is the exact specimen you will receive, photographed with a 1 cm scale cube for accurate sizing. Each piece is carefully selected for quality and authenticity. As with all of our fossils, it comes with a Certificate of Authenticity, ensuring it is a 100% genuine specimen.
Geological Context
The Upper Callovian forms part of the Middle Jurassic epoch, a dynamic interval characterised by shifting marine environments and thriving ammonite faunas. The Ryazan region of Russia is globally recognised for its well-preserved Callovian ammonites, which provide invaluable insights into Jurassic marine ecosystems. Fossils from these deposits often serve as index fossils, enabling precise correlation of rock layers across Europe and beyond.
During this period, shallow warm seas dominated the landscape, depositing fine-grained sediments that created perfect conditions for the preservation of ammonites. Hecticoceras, along with other genera, played a vital role in reconstructing the palaeogeography and biostratigraphy of the Jurassic world.
Scientific Classification
- Genus: Hecticoceras
- Subgenus: Brightia
- Species: Hecticoceras (Brightia) brightii
- Order: Ammonitida
- Superfamily: Perisphinctoidea
- Family: Hecticoceratidae
- Age: Jurassic, Upper Callovian (164 – 161 million years ago)
- Locality: Ryazan, Russia
Morphological Features
Hecticoceras (Brightia) brightii is notable for its distinctive and intricate shell features, which make it stand out within its family:
- Compressed, evolute shell with exposed inner whorls.
- Sharp, well-defined ribbing running across the flanks, providing strength and structural beauty.
- Subtle tubercles and nodules, particularly near the ventral area, adding a textured and ornamental quality.
- Complex suture patterns, typical of advanced ammonites, reflecting the sophisticated internal chamber system.
These features not only aid in identification but also highlight the evolutionary refinement of Jurassic ammonites, whose shell structures evolved to balance strength, buoyancy, and hydrodynamics.
Paleoecology and Significance
Hecticoceras belonged to the diverse order Ammonitida, a group of fast-moving, predatory marine molluscs closely related to modern squid and cuttlefish. Their chambered shells allowed precise buoyancy control, enabling them to hunt effectively in the mid-water column. Likely prey included small crustaceans, fish, and plankton.
The ribbing and tuberculation found on Hecticoceras (Brightia) brightii may have served dual purposes: reinforcing the shell against water pressure and predators, while potentially influencing hydrodynamic stability during movement. These adaptations reveal the ammonite’s successful occupation of Jurassic marine niches.
As an index fossil, Hecticoceras is critical to defining Upper Callovian biozones. Its stratigraphic distribution helps geologists accurately date and correlate marine sediments across Eurasia, making it both scientifically valuable and historically important.
Collector’s Appeal
This Hecticoceras (Brightia) brightii ammonite is an outstanding specimen that combines scientific value with aesthetic beauty. Its preservation from the famous Callovian deposits of Ryazan makes it highly desirable for both seasoned collectors and those seeking to add a unique fossil to their collection.
The distinctive ribbing and elegant shell structure display beautifully under natural light, while its historical and geological context offers a tangible connection to the rich ecosystems of the Jurassic seas. This specimen is also ideal for teaching collections, museums, or as a statement piece for display.
Key Details
- Species: Hecticoceras (Brightia) brightii
- Age: Jurassic, Upper Callovian (164 – 161 million years ago)
- Locality: Ryazan, Russia
- Family: Hecticoceratidae
- Features: Compressed evolute shell, sharp ribbing, complex sutures, authentic preservation
- Certificate of Authenticity included
- Exact specimen photographed with 1 cm scale cube
This rare Hecticoceras (Brightia) brightii ammonite fossil is a superb example of Jurassic life, combining remarkable natural preservation with important scientific heritage.
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