RARE Indosphinctes lobatus Fossil Ammonite Lower Callovian Jurassic France – Genuine Authentic Prehistoric Marine Cephalopod with COA

Description

Rare Lower Callovian Ammonite from Montreuil-Bellay, France

This listing features a rare Indosphinctes lobatus fossil ammonite from the Lower Callovian stage of the Middle Jurassic period, found in the fossil-rich deposits near Montreuil-Bellay, France. This exceptional specimen was carefully chosen for its high-quality preservation, distinctive ribbing, and excellent display appeal. The photographs provided show the actual specimen you will receive, ensuring complete transparency and authenticity.

Geological Age & Formation

Indosphinctes lobatus lived approximately 166.1 to 164.7 million years ago during the Lower Callovian stage. At that time, the Montreuil-Bellay region was submerged beneath warm, shallow epicontinental seas. These marine conditions, combined with fine sedimentation, created the ideal environment for the preservation of ammonite shells. Over millions of years, mineral-rich deposits replaced the original aragonite, producing beautifully detailed fossils that retain the shell’s intricate ornamentation. The region is well-known for its superb Jurassic marine fossils, making this piece a desirable addition to any serious collection.

Species Identification & Morphology

Belonging to the family Perisphinctidae within the superfamily Perisphinctoidea and order Ammonitida, Indosphinctes lobatus is characterised by its evolute shell, with all whorls visible from the side, and strong, bifurcating ribs that extend gracefully from the umbilicus to the venter. The ribbing pattern is regular and symmetrical, giving the shell both strength and aesthetic appeal. In this specimen, the ribs are well-preserved, and the suture lines—delicate, complex patterns marking the chamber boundaries—are visible in fine detail. These features make Indosphinctes lobatus a highly recognisable and scientifically significant ammonite species.

Collector Highlights

• Preservation: Excellent, with crisp ribbing and visible suture patterns.
• Size Reference: Scale rule cube in photos = 1 cm squares for accurate measurement.
• Authenticity: 100% genuine fossil, supplied with a Certificate of Authenticity.
• Provenance: Sourced from the Montreuil-Bellay fossil beds, France.
• Display Quality: A visually striking ammonite, ideal for display in a collector’s cabinet, office, or educational setting.
• Rarity: Indosphinctes lobatus is far less common on the open fossil market than many other Jurassic ammonites, adding to its value and appeal.

Paleoenvironment & Scientific Importance

During the Lower Callovian, Indosphinctes lobatus inhabited warm, nutrient-rich seas alongside other ammonites, bivalves, belemnites, and marine reptiles. It was a nektonic predator, actively swimming in open water and preying upon smaller invertebrates and juvenile fish. The chambered shell (phragmocone) allowed the animal to regulate buoyancy by adjusting the gas and liquid within its chambers, enabling it to move efficiently through different depths of the ocean.

This species is also an important index fossil for the Lower Callovian, allowing paleontologists to accurately date and correlate rock layers across different regions. Its distinctive shell morphology and ornamentation patterns make it a valuable tool for biostratigraphic studies.

A Stunning Piece of Jurassic History

With its sharp ribbing, clear suture detail, and excellent preservation, this Indosphinctes lobatus ammonite is both scientifically significant and visually captivating. It is perfect for dedicated fossil collectors, geology enthusiasts, educators, or anyone wishing to own a unique and authentic piece of natural history.

All of our fossils are 100% genuine specimens and come with a Certificate of Authenticity. The fossil pictured is the exact specimen you will receive.