Rare Pseudoschloenbachia griesbachi Ammonite Fossil Middle Campanian Cretaceous Tsiribina Madagascar Genuine Specimen

Description

Rare Pseudoschloenbachia griesbachi Ammonite Fossil

This listing offers a rare Pseudoschloenbachia griesbachi ammonite fossil, dating from the Middle Campanian Stage of the Cretaceous period, discovered in the celebrated fossil beds of Tsiribina, Madagascar. This specimen is an excellent example of a Late Cretaceous ammonite, combining robust morphology with diagnostic ornamentation that makes it both scientifically significant and visually impressive. The fossil pictured is the exact specimen you will receive, with a 1 cm scale cube included for size reference. Every specimen we sell is a 100% genuine fossil and is supplied with a Certificate of Authenticity.

Geological Age and Context

The Campanian Stage, spanning approximately 83.6–72.1 million years ago, is a key division of the Late Cretaceous. This stage is known for high sea levels, widespread shallow marine environments, and the continued flourishing of ammonites alongside marine reptiles, mosasaurs, and diverse invertebrate faunas. The Middle Campanian, in particular, was a time of evolutionary diversification among ammonites, with genera like Pseudoschloenbachia playing a prominent role. The Tsiribina region of Madagascar is a world-renowned fossil locality, producing ammonites of exceptional preservation that are crucial for both biostratigraphy and private collections.

Taxonomy and Classification

Pseudoschloenbachia griesbachi belongs to the genus Pseudoschloenbachia, within the family Schloenbachiidae, superfamily Acanthoceratoidea, and order Ammonitida. The Schloenbachiidae are well-known for their strongly ornamented shells, often with bold ribbing and prominent tubercles, reflecting evolutionary adaptations to dynamic marine environments. The genus Pseudoschloenbachia is particularly important because of its role in defining ammonite zones within the Campanian, with griesbachi serving as a significant marker species in biostratigraphic frameworks.

Morphological Features

The shell of Pseudoschloenbachia griesbachi is evolute, with earlier whorls visible and a bold, sculptured form. Strong ribs radiate across the flanks, often terminating in distinct tubercles or nodules that accentuate the overall ornamentation. The venter is frequently broad, with ribbing continuing across it in a well-defined pattern. These features are highly diagnostic, allowing paleontologists to identify the species with accuracy while also providing collectors with a strikingly detailed specimen. The rugged texture and pronounced ribbing give this ammonite a visually dramatic presence, making it a desirable fossil for both study and display.

Scientific and Collector Importance

Ammonites such as Pseudoschloenbachia griesbachi are crucial to Campanian biostratigraphy, acting as reliable index fossils due to their limited stratigraphic range and distinctive morphology. Their presence enables geologists to accurately correlate marine deposits across continents, offering vital insight into the Cretaceous world. For collectors, fossils of this species from Madagascar are especially prized because of their rarity, preservation quality, and provenance from one of the most important Cretaceous fossil regions. A specimen of this quality represents both a piece of paleontological history and a unique natural display item.

Provenance and Authenticity

This ammonite fossil was collected in Tsiribina, Madagascar, a classic Campanian locality famous for producing ammonites of outstanding preservation. Every specimen we provide is carefully chosen and guaranteed authentic. Each fossil comes with a Certificate of Authenticity to ensure full confidence in its scientific and collector value. Professional packaging and secure shipping guarantee that your specimen arrives safely and ready for display.

This is a rare Pseudoschloenbachia griesbachi ammonite fossil from the Middle Campanian of Madagascar. With its strong morphology, scientific importance, and striking appearance, it is an outstanding addition to any collection of ammonites, Cretaceous fossils, or natural history specimens.