Large Perisphinctes ammonite with other fossils embedded in it. Madagascar, Jurassic Period

Large Perisphinctes ammonite with inlays of other fossils. Madagascar, Jurassic, ca. 165–150 million years.
Condition: Good overall condition, with wear, concretions, and natural fractures typical of the fossilization process.
Origin: Madagascar.
Measurements: 50 cm tall; 14 cm at widest point.

A magnificent fossil specimen of an ammonite belonging to the genus Perisphinctes, from the important fossil-bearing deposits of Madagascar. The specimen stands out for its large size, the clear definition of its spiral structure, and the presence of natural incrustations of other Jurassic fossils, preserved alongside the main specimen for millions of years.

Ammonites were marine cephalopod mollusks, related to modern nautiluses, that inhabited prehistoric oceans for much of the Mesozoic Era. Their characteristic spiral-coiled shell, divided internally into chambers, is one of the most recognizable and prized fossils, valued both for its scientific significance and its aesthetic appeal. The genus Perisphinctes, particularly representative of the Jurassic period, is characterized by its evolute shell, with an open spiral and pronounced ribs—features clearly visible in this specimen.

Dating back an estimated 165 to 150 million years, this fossil offers an exceptional window into the Jurassic marine ecosystem. The shell’s pronounced radial ornamentation, with well-defined ribs running across the surface from the center toward the outer rim, clearly reveals the specimen’s natural structure and the complexity of its biological development.

The surface preserves incrustations and associated remains of other fossils, integrated into the natural matrix. These inclusions add significant paleontological value by evoking the sedimentary context in which the ammonite was deposited and fossilized. The coexistence of the main fossil with other mineralized organic elements lends the specimen a unique character, both from a scientific perspective and from a collector’s standpoint.