Sonninia aff Felix Ammonite Fossil Jurassic Dorset Genuine COA Card UK Specimen – Bajocian Inferior Oolite Sherborne

Description

Sonninia aff. Felix Ammonite Fossil from Sherborne, Dorset

This is a genuine Sonninia aff. Felix ammonite fossil from the Inferior Oolite Group, dating to the Middle Jurassic, Bajocian stage, collected from Sandford Lane, Sherborne, Dorset. This carefully chosen fossil is a highly collectable British Jurassic marine specimen, selected for its natural form, geological interest, and display appeal. It is supplied with a Certificate of Authenticity lifetime guarantee generic card, making it a trusted addition to an ammonite collection, natural history cabinet, educational geology display, or fossil gift selection.

The photograph shows the actual fossil specimen you will receive. Full sizing and scale can be seen in the photo.

Geological Age and Formation

This ammonite dates to the Bajocian stage of the Middle Jurassic, approximately 170 million years old. It comes from the Inferior Oolite Group, one of the classic fossil-bearing Jurassic rock units of southern England. The Inferior Oolite is well known for its marine limestones, iron-rich beds, shell debris, and diverse ammonite faunas, particularly across Dorset, Somerset, Gloucestershire, and surrounding regions.

The specimen is recorded from the Sauzei Zone, an important Bajocian ammonite biozone. Ammonite zones are used by geologists to date and correlate Jurassic rock layers, because ammonites evolved rapidly and often had wide geographic distribution. The presence of a zonal association adds scientific and collectable value, linking this fossil to a specific interval within the Middle Jurassic marine succession.

Fossil Type and Identification

This fossil is identified as Sonninia aff. Felix. The abbreviation “aff.” means the specimen shows close affinity to Sonninia felix, while allowing for natural variation or preservation differences. This is a careful scientific style of identification often used where a fossil strongly resembles a known species but is not assigned with absolute certainty.

Sonninia is a well-known genus of Jurassic ammonite and belongs to the ammonoid cephalopods, an extinct group of marine molluscs related to modern squid, cuttlefish, octopus, and nautilus. Ammonites had coiled external shells divided internally into chambers. The living animal occupied the outer body chamber, while earlier chambers helped regulate buoyancy, allowing it to move through the water column.

Morphology and Notable Features

Sonninia ammonites are appreciated for their classic Middle Jurassic appearance, often showing a strong coiled form, visible whorls, and attractive ribbing. Many examples have a moderately evolute shell, where earlier whorls remain visible around the central umbilicus. The ribs may curve across the flanks and help define the shell’s growth pattern, giving the fossil strong visual texture and natural display appeal.

The shell of an ammonite records the animal’s growth through life, with each new whorl representing a later stage of development. Internal chamber walls, known as septa, formed suture lines where they met the outer shell. These structures are important in ammonite classification and are part of why ammonites are among the most useful fossils for geological dating.

As a genuine fossil, this specimen may show natural matrix, fossil shell texture, mineralisation, colour variation, weathering, small chips, cracks, or areas of natural wear caused by fossilisation and geological history. These features are normal for authentic fossils and add to the individuality of the piece. The photo shows the exact specimen being offered, allowing the buyer to view its preservation, condition, size, and display quality before purchase.

Jurassic Marine Environment of Dorset

During the Bajocian, the area now known as Dorset was covered by warm shallow to moderately deep seas. These marine environments supported a rich ecosystem of ammonites, belemnites, bivalves, brachiopods, gastropods, echinoids, crinoids, fish, and other sea life. The Inferior Oolite Group formed from sediments deposited in these ancient seas, including carbonate-rich material and shell fragments that accumulated on the seabed.

Sonninia ammonites were active swimming or drifting marine animals, likely feeding on small prey in the water column using tentacles. After death, the shell could settle onto the seabed and become buried by sediment. Over millions of years, mineralisation, compaction, and geological change transformed the remains into a fossil, preserving a direct link to the Middle Jurassic seas of southern England.

Authenticity and Collectability

This Sonninia aff. Felix ammonite fossil is a genuine specimen from Sandford Lane, Sherborne, Dorset, dating to the Bajocian, Sauzei Zone of the Inferior Oolite Group. It is suitable for collectors of British fossils, Dorset fossils, Jurassic ammonites, Middle Jurassic marine fossils, natural history specimens, and educational geology pieces.

This carefully selected fossil includes a Certificate of Authenticity lifetime guarantee generic card, and the fossil shown in the photo is the actual specimen you will receive.