Rare Orthogarantiana schroederi Fossil Ammonite Inferior Oolite Jurassic Coast Burton Bradstock Dorset UK Genuine Specimen with COA

Exquisite Orthogarantiana schroederi Ammonite from the Inferior Oolite, Jurassic Coast, Dorset, UK

This exceptional Orthogarantiana schroederi fossil ammonite was discovered by our own team members, Alister and Alison, on 2 October 2025, at Burton Bradstock, Dorset, United Kingdom, along the iconic Jurassic Coast UNESCO World Heritage Site. Expertly cleaned, prepared, and treated by Alison, this specimen reveals intricate ribbing and a superbly preserved shell structure. Originating from the Inferior Oolite Formation, it dates to the Middle Jurassic Period (Bajocian Stage, approximately 170–168 million years ago) and represents a particularly fine and rare example of this ammonite species.

Geological and Depositional Context

The Inferior Oolite Formation was deposited in a warm, shallow marine environment during the Middle Jurassic, when much of southern England lay beneath subtropical seas. The sediments here consist of fine oolitic limestones, marls, and bioclastic sands — perfect for preserving delicate fossils in stunning detail.
The Burton Bradstock section forms part of the Jurassic Coast, one of the world’s most significant geological regions, famous for its continuous record of Jurassic life and sedimentation. Within the Inferior Oolite, the Garantiana Biozone marks a distinctive interval corresponding to the early Bajocian Stage. It is within these layers that Orthogarantiana schroederi occurs, a characteristic ammonite species that serves as a valuable biostratigraphic marker for dating Jurassic deposits across Europe.

Species Overview – Orthogarantiana schroederi

Orthogarantiana schroederi belongs to the family Stephanoceratidae, superfamily Stephanoceratoidea, order Ammonitida. It is an elegant, evolute ammonite with well-defined ribbing, flattened whorls, and pronounced ventrolateral tubercles. The ribs typically bifurcate toward the outer whorl, creating a visually striking pattern across the shell. This characteristic ornamentation distinguishes Orthogarantiana from other Bajocian ammonite genera, combining strength with refinement in its shell morphology.
The genus Orthogarantiana is closely related to Garantiana and represents a transitional form within the evolutionary lineage of Stephanoceratidae, showing adaptations suited to open marine environments. The hydrodynamic design of its shell suggests a free-swimming, nektonic lifestyle, navigating the mid-level water column while preying on small marine organisms. Its species epithet schroederi commemorates the German paleontologist who first formally described the taxon, contributing significantly to the understanding of Bajocian ammonite faunas.

Scientific and Historical Importance

Orthogarantiana schroederi holds great importance in Middle Jurassic paleontology as an index fossil for the early Bajocian. Its consistent presence within the Garantiana Biozone allows scientists to correlate marine deposits across different regions of Europe. Ammonites of this group demonstrate evolutionary progression and environmental adaptation during a time of high biodiversity in the Jurassic seas.
Fossils from the Burton Bradstock Inferior Oolite are especially prized for their preservation, often retaining fine ribbing and shell features that provide insights into the life habits of ancient cephalopods. The region has a long scientific legacy, first studied in the 19th century by British geologists who established the foundational principles of stratigraphy using ammonite assemblages like these. This specimen, with its detailed ornamentation and perfect form, continues that historical tradition — a bridge between scientific discovery and natural artistry.

Condition, Provenance, and Authenticity

This is a 100% genuine fossil specimen, professionally collected and prepared by our team. It has been cleaned and stabilised to reveal the fine details of its natural structure without altering its authenticity. The ammonite’s ribbing and tubercles are beautifully preserved, offering both aesthetic and scientific value. The photograph shows the exact specimen you will receive, ensuring complete transparency.
Each fossil we sell comes with a Certificate of Authenticity, verifying the species, locality, geological formation, and age.

Details at a Glance

• Species: Orthogarantiana schroederi

• Family: Stephanoceratidae

• Superfamily: Stephanoceratoidea

• Order: Ammonitida

• Age: Bajocian Stage, Middle Jurassic (~170–168 million years ago)

• Biozone: Garantiana Biozone

• Formation: Inferior Oolite

• Locality: Burton Bradstock, Dorset, United Kingdom

• Discovered by: Alister and Alison on 02 October 2025

• Prepared by: Alison

• Condition: Genuine, expertly prepared specimen; naturally preserved detail

• Scale: Cube = 1 cm (see photo for full sizing)

• Included: Certificate of Authenticity

A Remarkable Collector’s Fossil from Britain’s Jurassic Coast

This Orthogarantiana schroederi fossil ammonite represents the beauty and complexity of Jurassic life, perfectly preserved within the Inferior Oolite of Dorset. Its rarity, scientific importance, and provenance from the Jurassic Coast make it an exceptional specimen — ideal for collectors, educators, and admirers of Earth’s ancient marine heritage.