Rare Tragophylloceras Fossil Ammonite Green Ammonite Beds Lower Lias Jurassic Coast Golden Cap Seatown Dorset UK Genuine Specimen with COA

Exceptional Tragophylloceras Ammonite from the Green Ammonite Beds, Golden Cap, Dorset, UK

This magnificent Tragophylloceras fossil ammonite was discovered by our own team members, Alister and Alison, on 2 October 2025, at Golden Cap, near Seatown, Dorset, United Kingdom, along the world-famous Jurassic Coast UNESCO World Heritage Site. The specimen has been carefully cleaned, prepared, and treated by Alison, revealing beautiful natural ribbing and fine shell detail. Found in the Green Ammonite Beds of the Lower Lias Formation, this ammonite dates to the Early Jurassic Period (Sinemurian–Pliensbachian Stage, approximately 190–183 million years ago). It represents one of the most elegant and scientifically important ammonite types from Dorset’s Lower Jurassic sequence.

Geological and Depositional Context

The Green Ammonite Beds are part of the Lower Lias Formation, one of the most famous fossil-bearing units of the British Jurassic Coast. These beds, exposed spectacularly at Golden Cap, were deposited in a calm, shallow marine environment during the early Jurassic, when southern England lay beneath a warm, subtropical sea. Fine-grained mudstones and marls accumulated on the sea floor, providing excellent conditions for the preservation of ammonites and other marine life.
The characteristic “green” colour of these beds comes from traces of glauconite, an iron-rich mineral that forms in low-oxygen marine settings. This mineral not only contributes to the distinctive hue but also helped preserve delicate fossil shells in remarkable detail. The Golden Cap to Seatown section is one of the most fossiliferous localities along the Jurassic Coast, yielding ammonites that are crucial for dating Lower Jurassic strata. Among these, Tragophylloceras stands out for its aesthetic beauty and paleontological value.

Species Overview – Tragophylloceras

Tragophylloceras belongs to the family Eoderoceratidae, superfamily Eoderoceratoidea, order Ammonitida. This genus is known for its finely ribbed, moderately evolute shell and distinctive, gently curving ribs that often bifurcate towards the outer whorl. The shell is typically compressed with a smooth venter, giving it an elegant, symmetrical appearance. These features distinguish Tragophylloceras from its close relatives such as Eoderoceras and Liparoceras.
This genus occurs within the Tragophylloceras Loscombi Biozone, making it an important index fossil for the Sinemurian–Pliensbachian boundary interval. Its delicate ribbing and regular whorl expansion suggest a nektonic lifestyle, with the animal freely swimming in the open marine waters, using its coiled shell for buoyancy and stability. The species Tragophylloceras loscombi and related forms were first described from British localities, including Lyme Regis and Charmouth, and remain key taxa in Lower Jurassic ammonite studies.

Scientific and Historical Importance

Fossils from the Green Ammonite Beds have played an essential role in shaping the study of Jurassic paleontology. The site is closely associated with the pioneering fossil discoveries of Mary Anning and other early collectors of the 19th century, whose work in the same strata laid the foundation for modern paleontology. Tragophylloceras is a key genus in understanding ammonite evolution during the early Jurassic, bridging the morphological transition between earlier planulate ammonites and the more ornate forms of the Pliensbachian.
The ammonites from Golden Cap are also highly sought after for their aesthetic beauty — often preserved with a natural iron-stained or glauconitic finish that highlights their ribbing and fine detail. This combination of scientific importance and visual appeal makes this specimen a standout piece for collectors.

Condition, Provenance, and Authenticity

This is a 100% genuine fossil ammonite, professionally collected and prepared by our own team. The shell is finely detailed, with natural ribbing and clear whorl definition characteristic of Tragophylloceras. The fossil has been stabilised and treated by Alison using professional methods to ensure long-term preservation. The photograph shows the exact specimen you will receive, guaranteeing authenticity and transparency.
A Certificate of Authenticity accompanies your purchase, verifying the fossil’s identity, provenance, and geological age.

Details at a Glance

• Genus: Tragophylloceras

• Family: Eoderoceratidae

• Superfamily: Eoderoceratoidea

• Order: Ammonitida

• Age: Sinemurian–Pliensbachian, Early Jurassic (~190–183 million years ago)

• Biozone: Tragophylloceras Loscombi Biozone

• Formation: Green Ammonite Beds, Lower Lias

• Locality: Golden Cap, Seatown, Dorset, United Kingdom

• Discovered by: Alister and Alison on 02 October 2025

• Prepared by: Alison

• Condition: Genuine, carefully cleaned and stabilised fossil specimen

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

• Included: Certificate of Authenticity

A Classic Collector’s Fossil from Britain’s Jurassic Heritage

This Tragophylloceras ammonite from the Green Ammonite Beds at Golden Cap is a timeless piece of natural history. Combining scientific significance with natural beauty, it captures the story of life and preservation on the ancient Jurassic sea floor — a stunning addition to any fossil collection or display of geological treasures.