4″ Brasilia Fossil Ammonite Bajocian Jurassic Dorset UK Genuine Horn Park Ammonite Specimen with Certificate of Authenticity

Description

Authentic 4″ Brasilia Fossil Ammonite

This specimen is a striking 4-inch Brasilia ammonite fossil from the Bajocian stage of the Middle Jurassic, collected at the famous Horn Park site in Dorset, United Kingdom. Beautifully preserved with its ribbing and coiling clearly visible, this ammonite is both an attractive display piece and a scientifically valuable specimen. The photographs provided show the exact fossil you will receive, with a 1 cm scale cube and rule squares included for accurate size reference. Every fossil we supply is 100% genuine and accompanied by a Certificate of Authenticity.

Geological Context – Bajocian of Horn Park, Dorset

The Bajocian stage, dating to approximately 170.3–168.3 million years ago, represents a key interval of the Middle Jurassic when ammonites were particularly abundant and diverse. The Horn Park Quarry in Dorset is one of the most important fossil localities in Britain for Bajocian ammonites and is recognised for the exceptional preservation and variety of species it produces. These sediments formed in shallow, warm marine environments where lime-rich muds accumulated, providing ideal conditions for the fossilisation of ammonites and other marine life. Today, fossils from Horn Park are sought after by collectors worldwide for their quality and stratigraphic significance.

Species Overview – Brasilia Ammonites

The genus Brasilia belongs to the order Ammonitida, superfamily Hildoceratoidea, and is well known from Bajocian deposits of Europe. These ammonites are distinguished by their evolute coiling, robust ribbing, and relatively wide whorls. The ribs often bifurcate as they cross the shell flanks, giving the ammonite a distinctive ornamental appearance. The genus is also important in biostratigraphy, helping palaeontologists to identify specific biozones within the Bajocian stage, particularly in correlation with other European Jurassic localities.

Morphological Features

This 4-inch specimen of Brasilia showcases the typical morphology of the genus. The shell displays clear, radiating ribs that bifurcate across the flanks before reaching the outer whorl margin (venter). Its coiling is moderately evolute, meaning that earlier whorls remain partially visible, and the whorls themselves are broad and slightly compressed. These features make it easy to distinguish Brasilia from related ammonite genera. The specimen demonstrates both the elegance and robustness of Jurassic ammonite shells, capturing details that highlight evolutionary adaptations to the marine environments of the time.

Scientific and Collectible Importance

Brasilia ammonites are not only attractive for collectors but also vital for understanding Jurassic stratigraphy and ammonite evolution. Their presence helps to define particular intervals within the Bajocian stage, making them useful index fossils. For private collectors, this fossil offers a combination of aesthetic appeal and scientific value, representing an ammonite species directly tied to the rich geological history of the Dorset coast. For students and researchers, it provides a tangible example of Middle Jurassic ammonite diversity and morphology.

Provenance and Guarantee

This fossil comes from Horn Park, Dorset, a classic British locality famous for Bajocian ammonites. It has been carefully selected for preservation, clarity of features, and display quality. As with all of our specimens, it is 100% genuine and comes with a Certificate of Authenticity. The photographs provided show the exact ammonite you will receive, ensuring transparency and provenance.

A Rare Jurassic Ammonite from Dorset

This 4-inch Brasilia ammonite fossil from the Bajocian of Horn Park, Dorset is an exceptional specimen for collectors, educators, and enthusiasts alike. Its combination of size, preservation, and scientific value makes it a highly desirable piece, connecting you directly to the marine ecosystems of Britain’s Jurassic seas.