RARE Distichoceras bidentatus iridescent Fossil Ammonite Middle Callovian Jurassic Russia

Description

Rare Distichoceras bidentatus Iridescent Fossil Ammonite from Russia

This listing features a rare and authentic Distichoceras bidentatus ammonite fossil, dating to the Middle Callovian stage of the Jurassic period, approximately 165 – 161 million years ago. Discovered in the renowned fossil-rich region of Ryazan, Russia, this specimen represents a striking example of ammonite preservation, with a natural iridescent nacre that shimmers in vivid hues when viewed under light.

Every fossil we sell is a genuine, carefully chosen specimen, and the photographs provided show the exact piece you will receive. A 1 cm scale cube is included in the photos for accurate size reference. Your fossil will also come with a Certificate of Authenticity, ensuring that it is a scientifically genuine and historically significant specimen.

Geological Context

The Middle Callovian stage of the Jurassic period was a time of expansive shallow seas across what is now Europe and western Russia. These seas were teeming with life, and the fine-grained marine sediments in the Ryazan area provided ideal conditions for the preservation of ammonites and other marine organisms.

Ammonites from this stage, including Distichoceras bidentatus, are used as important index fossils, helping paleontologists to date and correlate Jurassic rock layers across different regions. Their wide distribution, rapid evolutionary turnover, and distinctive morphological features make them vital to geological studies.

Scientific Classification

• Genus: Distichoceras
• Species: Distichoceras bidentatus
• Order: Ammonitida
• Superfamily: Stephanoceratoidea
• Family: Aspidoceratidae

This classification places Distichoceras among the Aspidoceratidae, a family of ammonites well-known for their ornate shell ornamentation and role as keystone fossils of the Middle to Late Jurassic.

Morphological Features

This specimen of Distichoceras bidentatus shows the characteristic features of its species:

• Biconcave rib structure, giving it its distinctive “bidentatus” name.
• An evolute shell form with exposed inner whorls, making the ribbing highly visible.
• Strongly developed ornamentation and ribbing across the outer whorl.
• A complex suture line, beautifully preserved and intricate in pattern.
• Natural iridescent nacre, adding a rainbow sheen that enhances its visual appeal.

These traits combine to make the fossil not only a scientifically valuable specimen but also an attractive natural display piece.

Paleoecology and Lifestyle

Like other ammonites, Distichoceras bidentatus was a marine cephalopod, closely related to modern squids and cuttlefish. It likely inhabited open shallow seas, using its coiled shell for buoyancy control. Its ribbed and ornate shell may have provided protection against predators while also playing a role in hydrodynamics.

During the Middle Callovian, ammonites such as this lived alongside diverse marine fauna, including bivalves, gastropods, belemnites, and marine reptiles such as ichthyosaurs and pliosaurs. This fossil is a direct remnant of that ancient marine ecosystem.

Collector’s Value

Fossils of Distichoceras bidentatus are highly sought after by collectors due to their rarity, distinctive morphology, and the brilliance of their natural iridescence. Specimens from Ryazan are especially prized for the preservation quality, with shells that retain the original nacreous layers in stunning condition.

Owning such a specimen is not only a matter of geological interest but also an opportunity to possess a striking piece of Earth’s natural history, formed over 160 million years ago in the seas of the Jurassic.

Key Features

• Species: Distichoceras bidentatus
• Age: Jurassic, Middle Callovian (approx. 165 – 161 million years old)
• Origin: Ryazan, Russia
• Family: Aspidoceratidae, 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 remarkable ammonite fossil represents a rare and visually stunning specimen, combining scientific significance, natural beauty, and excellent preservation—a true treasure for any fossil enthusiast or serious collector.