Description
Rare Pseudosonneratia typica Ammonite Fossil from Peru
This is an outstanding and rare specimen of Pseudosonneratia typica, a beautifully preserved ammonite fossil from the Albian stage of the Early Cretaceous period, approximately 113–100 million years ago. It was discovered in the Chulec Formation of the Machay Group, near Proya, Peru, a locality known for yielding exceptionally fine and scientifically significant ammonite fossils. The fossil you see in the photographs is the exact specimen you will receive, photographed alongside a 1 cm scale cube for accurate sizing reference. As with all of our offerings, this specimen is a 100% genuine fossil and is supplied with a Certificate of Authenticity.
Geological Context – Chulec Formation, Machay Group
The Chulec Formation forms part of the Machay Group in Peru and represents marine deposits laid down during the Albian stage of the Cretaceous. This formation is primarily composed of calcareous sediments, including marls and limestones, which were deposited in a shallow marine environment along the western margin of Gondwana. During the Albian, global sea levels were rising, creating widespread shallow seas that supported diverse marine life.
These environments offered ideal conditions for the preservation of ammonites, which thrived in the warm, nutrient-rich waters of the time. Fossils from this region provide valuable insights into Cretaceous paleoenvironments of South America and contribute to global biostratigraphic frameworks.
Scientific Classification
- Genus: Pseudosonneratia
- Species: Pseudosonneratia typica
- Family: Desmoceratidae
- Superfamily: Desmoceratoidea
- Order: Ammonitida
- Geological Stage: Albian, Early Cretaceous (c. 113–100 million years ago)
- Formation: Chulec Formation, Machay Group
- Locality: Proya, Peru
Morphological Features
Pseudosonneratia typica is a highly distinctive ammonite, valued both for its rarity and for its striking shell characteristics:
- A robust, involute shell with deep umbilicus.
- Strong ribbing, often sinuous, running across the whorls.
- Ornamentation that may include subtle tubercles along the ribs.
- Sutures showing the complex, lobed and saddled patterns typical of ammonites within the Desmoceratidae family.
The balance of symmetry and ornamentation in this species makes it not only scientifically important but also aesthetically appealing as a collector’s display specimen.
Paleontological Importance
Ammonites of the genus Pseudosonneratia are key representatives of the Desmoceratidae family, a group that diversified significantly during the Early Cretaceous. Their presence in the Chulec Formation provides crucial data for paleontologists in reconstructing biostratigraphic zonations and marine ecosystems of the Albian.
Because ammonites evolved rapidly and had wide geographic distribution, species such as P. typica are invaluable index fossils, used to correlate marine sediments across continents. This specimen not only represents a beautiful collector’s piece but also a significant marker in Earth’s geological and evolutionary history.
Depositional Environment – Albian Marine Seas
During the Albian stage, much of western South America, including modern-day Peru, was submerged beneath shallow seas. These seas were part of a global marine transgression linked to tectonic plate activity and rising sea levels. The environment was warm, with abundant plankton and other marine organisms forming the basis of a rich food chain.
Ammonites like Pseudosonneratia typica were active swimmers in these waters, likely preying on smaller molluscs, crustaceans, and other planktonic animals. Their abundance and diversity in the fossil record make them excellent indicators of marine ecosystem health and evolutionary trends during the Cretaceous.
Collector and Display Value
This Pseudosonneratia typica ammonite fossil is an exceptional example from the renowned Chulec Formation of Peru. Its rarity, combined with its excellent preservation and distinctive morphology, makes it a highly desirable piece for both amateur and advanced fossil collectors.
The fossil represents an authentic piece of natural history, formed over 100 million years ago in the ancient seas of South America. Supplied with a Certificate of Authenticity and carefully chosen for its scientific and aesthetic qualities, this specimen is perfect for display, teaching, or as a unique addition to any collection of Cretaceous fossils.
Key Details
- Fossil Type: Ammonite
- Species: Pseudosonneratia typica
- Family: Desmoceratidae
- Age: Albian, Early Cretaceous (c. 113–100 million years old)
- Formation: Chulec Formation, Machay Group
- Locality: Proya, Peru
- Supplied with Certificate of Authenticity
- Exact specimen shown in photographs with 1 cm scale cube
This rare Pseudosonneratia typica ammonite fossil offers both scientific significance and natural beauty, making it a truly special addition to any collection.
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