RARE Rondiceras tcheffkini iridescent Fossil Ammonite Middle Callovian Jurassic Russia

Description

Rare Rondiceras tcheffkini Iridescent Fossil Ammonite from Russia

Presented here is a rare and beautifully preserved Rondiceras tcheffkini ammonite fossil, dating to the Middle Callovian stage of the Jurassic period, approximately 165 – 161 million years old. This striking specimen originates from the famous fossil-bearing deposits of Michailov, Russia, a locality celebrated for producing ammonites with remarkable shell preservation and vibrant iridescence.

The fossil exhibits natural nacreous layers, which refract light into shimmering shades of green, gold, and violet, making it a specimen of both scientific and aesthetic significance. The photographs show the exact fossil you will receive, with a 1 cm scale cube included for reference. Every fossil we offer is carefully chosen for quality and supplied with a Certificate of Authenticity, ensuring you own a genuine piece of natural history.

Geological Context

This ammonite comes from the Middle Callovian stage of the Jurassic, a time when shallow epicontinental seas covered much of Europe and western Russia. These warm, nutrient-rich marine environments supported abundant life, with ammonites thriving as some of the most successful cephalopods of their time. The Michailov region is particularly renowned for its marine clays and fine-grained sediments that captured and preserved delicate shell structures in exceptional detail.

The Callovian deposits are of major importance in stratigraphy because ammonites such as Rondiceras tcheffkini serve as index fossils, helping geologists to date and correlate layers across broad regions.

Scientific Classification

• Genus: Rondiceras
• Species: Rondiceras tcheffkini
• Order: Ammonitida
• Superfamily: Stephanoceratoidea
• Family: Cardioceratidae

Belonging to the Cardioceratidae, Rondiceras is part of a lineage characterised by their strongly ribbed shells and distinctive suture patterns. These features make them highly recognisable and scientifically significant among Middle Jurassic ammonites.

Morphological Features

This specimen of Rondiceras tcheffkini displays the diagnostic traits of its genus and species:

• Evolute shell structure with exposed inner whorls.
• Strongly defined ribbing across the shell surface, providing structural strength.
• Complex suture patterns, beautifully preserved and visible in fine detail.
• Natural iridescent nacre, creating a rainbow-like lustre unique to well-preserved specimens.

These features highlight both the aesthetic beauty and paleontological importance of the specimen.

Paleoecology and Lifestyle

Ammonites such as Rondiceras tcheffkini were active marine predators, closely related to modern squids and cuttlefish. They likely fed on plankton, crustaceans, and small fish, propelling themselves through the water using jet propulsion. Their ribbed shells were not only structurally functional but may have played a role in hydrodynamics or camouflage within the Jurassic seas.

The Middle Jurassic seas where this ammonite lived also hosted marine reptiles, bivalves, gastropods, and numerous other ammonite species. This specimen is a direct link to that dynamic marine ecosystem, offering insight into the biodiversity of the Callovian seas.

Collector’s Significance

This Rondiceras tcheffkini ammonite is a highly desirable fossil, combining rarity, scientific importance, and striking natural beauty. Specimens from Michailov are prized for their preservation quality and iridescent displays, making them stand out in both private and institutional collections.

The iridescent nacre not only enhances its visual appeal but also demonstrates the remarkable preservation of Jurassic fossils in this region. Such specimens are increasingly rare to source, particularly in this condition, making this ammonite an exceptional acquisition for any serious collector.

Key Features

• Species: Rondiceras tcheffkini
• Age: Jurassic, Middle Callovian (approx. 165 – 161 million years old)
• Origin: Michailov, Russia
• Family: Cardioceratidae, Superfamily Stephanoceratoidea
• Features: Evolute shell, ribbed ornamentation, complex sutures, iridescent nacre
• Supplied with a Certificate of Authenticity
• Exact specimen shown in photographs with 1 cm scale cube

This rare fossil offers a perfect balance of scientific value, geological history, and natural beauty, making it a unique and treasured addition to any fossil or natural history collection.