Oppelia subcostata Fossil Ammonite Lower Bajocian Jurassic Caen France with Certificate of Authenticity

Description

This listing is for a fine Oppelia (Oppelia) subcostata ammonite fossil, dating from the Lower Bajocian stage of the Middle Jurassic Period, approximately 171–170 million years ago. Discovered in the historic fossil-bearing deposits near Caen, Normandy, France, this specimen represents a scientifically important ammonite species and a highly attractive piece for collectors of Jurassic fossils.

All of our fossils are 100% genuine specimens and are supplied with a Certificate of Authenticity. The photographs show the exact specimen you will receive, with a 1 cm scale cube and rule squares included for accurate sizing.

Geological Context and Age

This ammonite originates from the Lower Bajocian stage, part of the Middle Jurassic, a period when Europe was covered by shallow epicontinental seas linked to the Tethys Ocean. These warm, oxygen-rich waters provided ideal conditions for ammonites, belemnites, brachiopods, and early marine reptiles to flourish.

The Caen region of Normandy is one of France’s classic Jurassic fossil localities, famous for its limestone sequences and abundant ammonite faunas. The Inferior Oolite facies exposed in this area is particularly rich in ammonites of the genus Oppelia, which serve as key index fossils for refining the Jurassic timescale and correlating Bajocian deposits across Europe.

Morphology and Distinctive Features

Oppelia (Oppelia) subcostata belongs to the family Oppeliidae, within the superfamily Haploceratoidea of the order Ammonitida. This species is characterised by a discoidal, compressed shell with strongly involute coiling that conceals earlier whorls. Its name, subcostata, refers to the presence of faint costae (ribs) along the flanks, which are less pronounced than in related species but still provide a distinctive ornamentation.

The venter (outer rim) is generally narrow and smoothly rounded, while the sutures are moderately complex. This streamlined morphology suggests a nektonic lifestyle, with Oppelia subcostata adapted for active swimming in the open water column, preying on small marine organisms.

Scientific Importance

Oppelia (Oppelia) subcostata is a significant ammonite for Jurassic biostratigraphy. Its clearly defined stratigraphic range makes it a valuable index fossil for the Lower Bajocian, allowing precise dating and correlation of rock layers. This makes specimens such as this one indispensable for reconstructing the stratigraphic framework of the Middle Jurassic.

The species also provides important insight into the evolutionary trends of the Oppeliidae family, which became one of the dominant ammonite lineages during the Middle and Late Jurassic. By studying the morphology and distribution of Oppelia subcostata, palaeontologists gain a clearer understanding of ammonite palaeobiogeography and environmental adaptation.

Collector and Display Value

This Oppelia (Oppelia) subcostata ammonite fossil from Caen, Normandy is both scientifically valuable and visually striking. Its compressed, discoidal form and delicate ribbing make it an elegant specimen for display, while its provenance from one of France’s most famous Jurassic fossil localities adds to its desirability.

For collectors of ammonites, Jurassic fossils, or French specimens, this ammonite represents an ideal addition. It is equally suited to educational collections, where it can be used to illustrate the role of ammonites as index fossils and their importance in Jurassic stratigraphy.

Your Guarantee of Authenticity

• 100% genuine Oppelia (Oppelia) subcostata ammonite fossil from Caen, Normandy, France
• Geological age: Lower Bajocian stage, Middle Jurassic (approx. 171–170 million years old)
• From the classic Inferior Oolite facies of Normandy
• Supplied with a Certificate of Authenticity
• Exact specimen shown in photographs (no stock images used)
• Scale cube and rule squares = 1 cm (see photos for accurate sizing)

This Oppelia (Oppelia) subcostata ammonite fossil is a scientifically important and beautifully preserved specimen from the Bajocian deposits of Caen. With its rarity, elegant morphology, and guaranteed authenticity, it is a superb addition to any fossil collection.