Rare Kosmoceras ornatum Fossil Ammonite Upper Callovian Jurassic Russia Genuine Specimen

Description

Rare Kosmoceras ornatum Ammonite from Russia

This listing offers a rare Kosmoceras ornatum ammonite fossil, a striking and scientifically significant specimen from the Upper Callovian stage of the Middle Jurassic, dating to around 164–161 million years ago. Sourced from Russia, this ammonite represents a member of one of the most ornate and recognisable genera of Jurassic ammonites. The specimen’s detailed ribbing, tubercles, and complex suture patterns make it a superb example of the species. The ammonite shown in the photos is the exact piece you will receive, with a 1 cm scale cube included for precise sizing. Every fossil we sell is guaranteed authentic and comes with a Certificate of Authenticity.

Geological Context: The Upper Callovian

The Callovian stage is part of the Middle Jurassic, spanning approximately 166–161 million years ago. During this period, shallow seas spread across much of Europe and Asia, supporting a diverse array of ammonites, marine reptiles, and invertebrates. Russia’s Jurassic deposits are particularly renowned for yielding beautifully preserved specimens of Kosmoceras. The Upper Callovian succession is of great importance to palaeontologists because ammonites such as Kosmoceras ornatum are used as biostratigraphic markers, helping define zones that correlate rock layers across vast geographic areas.

Taxonomy and Classification

• Genus: Kosmoceras
• Species: Kosmoceras ornatum
• Family: Kosmoceratidae
• Superfamily: Stephanoceratoidea
• Order: Ammonitida
• Age: Upper Callovian, Jurassic (~164–161 million years ago)
• Locality: Russia

As part of the Kosmoceratidae family, this ammonite is known for its strong ornamentation and its wide stratigraphic distribution across Europe and Eurasia.

Morphological Features

This specimen of Kosmoceras ornatum shows classic diagnostic traits:

• Broad, involute shell coiling with tightly overlapping whorls.
• Thick, prominent ribs that extend strongly across the flanks.
• Tubercles and nodules positioned along the ribs, giving the shell a distinctive ornate appearance.
• Complex sutures, reflecting the intricate growth pattern typical of the genus.

These features make Kosmoceras ornatum one of the most visually striking ammonites of the Jurassic, highly sought after by collectors.

Scientific Importance

Beyond its aesthetic appeal, Kosmoceras ornatum is of great biostratigraphic value, used in defining the Kosmoceras ornatum Zone within the Callovian stage. Its widespread distribution makes it an essential tool for correlating Callovian marine strata throughout Europe and Russia. Specimens such as this one provide key evidence of Jurassic biodiversity and evolutionary trends within the ammonites.

Collecting Significance

For collectors, this fossil represents both a scientifically important and visually stunning specimen. Its ornate shell details stand out beautifully when displayed, making it a centrepiece in any fossil collection. The rarity of well-preserved Kosmoceras ornatum specimens from Russia adds to its desirability.

Key Details

• Fossil Type: Ammonite
• Species: Kosmoceras ornatum
• Age: Upper Callovian, Middle Jurassic (~164–161 million years ago)
• Location: Russia
• Features: Thick ribbing, nodules, ornate ornamentation, complex sutures
• Authenticity: Guaranteed with Certificate of Authenticity

Authenticity and Guarantee

We take pride in offering only 100% genuine fossils. This Kosmoceras ornatum ammonite is a rare and exceptional specimen, carefully chosen for its scientific importance and striking appearance. It comes fully authenticated and ready for collectors who wish to own a unique piece of Earth’s history, preserved for over 160 million years.