Fossil Ammonite Indosphinctes petaini Lower Callovian Jurassic Deux Sevres France Authentic Collectors Specimen with COA

Description

This listing is for a genuine fossil ammonite, Indosphinctes petaini, from the Lower Callovian stage of the Middle Jurassic (approximately 166–164 million years ago). Collected in Deux Sèvres, France, this ammonite has been carefully chosen for its preservation, natural beauty, and scientific significance. The photographs show the exact specimen you will receive, with a scale cube = 1 cm included for accurate sizing. All of our fossils are 100% genuine specimens and come complete with a Certificate of Authenticity.

Geological Context: Lower Callovian Stage

The Callovian stage is part of the Middle Jurassic and represents a period when shallow epicontinental seas spread across much of Europe. In what is now western France, these seas deposited fossil-rich clays, marls, and limestones that preserve an exceptional record of marine life.

The Lower Callovian is especially important for paleontologists, as ammonites from this interval are widely used as index fossils, allowing scientists to date and correlate Jurassic rock sequences across Europe. Fossils such as Indosphinctes petaini provide critical evidence for reconstructing ancient marine ecosystems and refining the stratigraphic framework of the Jurassic period.

The Species: Indosphinctes petaini

Indosphinctes petaini is a member of the order Ammonitida, superfamily Perisphinctoidea, and family Perisphinctidae. Ammonites within this group are characterised by their robust shells and highly ornamented ribbing patterns.

The shell of I. petaini is typically planispiral with compressed whorls, showing strong ribs that may bifurcate across the flanks. These ribs not only provided structural support but also served as a diagnostic feature for identifying the species. Its distinctive ribbing pattern makes it one of the more recognisable ammonites of the Lower Callovian.

As a nektonic predator, Indosphinctes petaini lived in open marine waters, actively swimming and preying on small molluscs, crustaceans, and other invertebrates. The elegant balance between form and function in its shell demonstrates the evolutionary success of ammonites in Jurassic seas.

Morphological and Scientific Features

• Order: Ammonitida
• Superfamily: Perisphinctoidea
• Family: Perisphinctidae
• Genus and Species: Indosphinctes petaini
• Geological Stage: Lower Callovian, Middle Jurassic (c. 166–164 Ma)
• Locality: Deux Sèvres, France
• Shell Traits: Strong ribbing, bifurcating ribs, compressed whorls, planispiral coiling
• Scientific Significance: Index fossil for Lower Callovian stratigraphy

The ribbed ornamentation and compressed coiling of Indosphinctes petaini not only make it a visually appealing specimen but also a scientifically valuable fossil. Its role as an index fossil highlights its importance in paleontological research and stratigraphic studies.

Collector and Display Value

This specimen of Indosphinctes petaini is both a scientifically significant fossil and a beautiful collector’s piece. Ammonites from the Callovian deposits of Deux Sèvres are prized by fossil enthusiasts for their rarity and preservation.

Its bold ribbing and natural form make it a striking display item, while its scientific value ensures its relevance for educational collections and research. Owning this ammonite provides a direct link to the Jurassic seas that covered much of Europe over 160 million years ago.

All of our specimens are carefully prepared and supplied with a Certificate of Authenticity. This Indosphinctes petaini ammonite is an excellent choice for collectors, educators, and anyone with an appreciation for Earth’s deep history.