Rare Pseudomercaticeras rotaries Ammonite Fossil, Upper Toarcian Stage Jurassic, Authentic Apennines Italy Collectors Specimen with COA

Description

Authentic Jurassic Ammonite Fossil

This listing offers a genuine Pseudomercaticeras rotaries Ammonite Fossil from the Upper Toarcian Stage of the Early Jurassic period, discovered in the Apennine Mountains of Italy. Ammonites were marine cephalopods belonging to the subclass Ammonoidea and order Ammonitida, closely related to squid and cuttlefish. Their chambered, coiled shells are among the most distinctive fossils, prized for their intricate morphology and immense scientific importance. The fossil has been carefully selected to highlight its natural features, and the photographs show the exact specimen you will receive. A 1 cm scale cube is included for reference.

Geological Context – Upper Toarcian, Jurassic

The Upper Toarcian, dating to around 177–174 million years ago, marks a key stage of the Early Jurassic. This interval followed the Early Toarcian Oceanic Anoxic Event, during which global changes in ocean chemistry reshaped marine ecosystems. The Apennines region of Italy is renowned for its fossiliferous deposits, which preserve ammonites in exquisite detail.

Ammonites from this stage are especially valuable to paleontologists because they serve as index fossils. Their rapid evolution and wide distribution make them essential for dividing the Jurassic into precise ammonite biozones, which allow geologists to correlate strata across Europe. Specimens such as Pseudomercaticeras rotaries therefore have both scientific and collector significance.

Species Profile – Pseudomercaticeras rotaries

The ammonite Pseudomercaticeras rotaries belongs to the family Hildoceratidae, within the superfamily Hildoceratoidea. Members of this family are characterised by their compressed whorl profiles, distinct ribbing, and evolute coiling.

Key identifying traits of Pseudomercaticeras rotaries include:

• Evolute shell coiling with a relatively wide umbilicus.
• Fine, evenly spaced ribs running across the flanks to the venter.
• A compressed, elegant whorl section, typical of the genus.
• Suture patterns revealing complex septal structures, visible in well-preserved examples.

These features distinguish Pseudomercaticeras rotaries from other Toarcian ammonites and highlight its importance in stratigraphy and fossil collections.

Paleoenvironment and Scientific Importance

During the Early Jurassic, the Apennines were submerged beneath warm, shallow seas that supported abundant marine life, including ammonites, belemnites, bivalves, and marine reptiles. Ammonites such as Pseudomercaticeras rotaries lived as nektonic predators, actively swimming in the water column and feeding on smaller organisms. After death, their shells settled on the seabed, where fine sediments preserved them for millions of years.

The restricted stratigraphic range of Pseudomercaticeras rotaries makes it particularly important for defining ammonite biozones within the Upper Toarcian. Collectors value this species not only for its scientific role but also for the striking detail of its ribbing and shell structure, making it an excellent display specimen.

100% Genuine with Certificate of Authenticity

All of our specimens are guaranteed 100% genuine and come with a Certificate of Authenticity. This ammonite is an authentic relic of Jurassic seas, not a cast or reproduction, preserved naturally for nearly 175 million years.

A Collector’s and Display Fossil

This Pseudomercaticeras rotaries ammonite fossil from the Apennines of Italy is an exceptional specimen for collectors, educators, and paleontology enthusiasts. Its striking morphology, precise geological provenance, and scientific significance make it a standout addition to any fossil collection or educational display.

Scale Rule Squares / Cube = 1 cm. Please see listing photos for the full sizing of this exact specimen.