Kosmoceras Ammonite Fossil from Jurassic Callovian Kellaways Beds Latton Quarry Cotswold Water Park Swindon UK

Description

Geological Context and Provenance

This specimen is a genuine Kosmoceras ammonite fossil from the Kellaways Beds, Callovian Stage of the Middle Jurassic (approximately 166 – 163 million years ago). It was discovered at Latton Quarry, Cotswold Water Park, near Swindon, UK, a site renowned for producing exceptionally preserved Jurassic ammonites. The Kellaways Beds were deposited in shallow marine conditions during a time when southern England was submerged beneath a warm, epicontinental sea.

The Callovian Stage is an important interval in Jurassic geology, recognised for its diverse ammonite fauna which provides a reliable biostratigraphic framework. Among these, Kosmoceras is one of the most distinctive genera and serves as an essential index fossil for correlating Callovian deposits across Europe.

Fossil Type and Species Details

The genus Kosmoceras belongs to the Order Ammonitida, Superfamily Stephanoceratoidea, and Family Kosmoceratidae. Ammonites of this group are known for their ornate ribbing, complex shell morphology, and stratigraphic importance.

Kosmoceras specimens are characterised by their evolute coiling, broad whorl sections, and a combination of ribbing and tuberculation that make them visually striking. They are commonly associated with well-defined biozones in the Callovian, providing both scientific and collector value.

Morphological Features

This ammonite shows the key diagnostic traits of Kosmoceras:

• Evolute Coiling – Exposed inner whorls with a wide umbilicus.
• Strong Ribbing – Prominent ribs that radiate from the umbilicus and extend across the flanks.
• Tubercles – Knots or spines at rib intersections, adding both ornamentation and defensive adaptation.
• Complex Sutures – Intricate suture lines typical of ammonites, visible where preserved.

The combination of ribbing and tuberculation makes Kosmoceras one of the most recognisable ammonites of the Callovian seas.

Depositional Environment

The Kellaways Beds were laid down in a shallow marine shelf setting, consisting of fine sandy clays and silts. This environment supported a rich ecosystem of molluscs, echinoderms, marine reptiles, and crustaceans. Rapid burial in soft sediment often resulted in well-preserved ammonite fossils, retaining exquisite rib and tubercle detail.

Scientific and Collector Importance

• Biostratigraphic Role – Kosmoceras is a defining fossil for Callovian stratigraphy, helping geologists to correlate sedimentary layers across Europe.
• Collector’s Appeal – Its ornate ribbing, tuberculated ornament, and distinctively coiled form make it a prized addition to private collections.
• Educational Value – Demonstrates evolutionary adaptation and Jurassic marine biodiversity, making it suitable for display in academic or teaching settings.

Authenticity and Display

• 100% Genuine Specimen – Backed by a Certificate of Authenticity.
• Exact Fossil Supplied – The photographs show the actual specimen you will receive.
• Sizing Reference – Scale rule squares / cube = 1 cm; see photos for full dimensions.

This Kosmoceras ammonite fossil from the Callovian, Jurassic of Latton Quarry, Swindon represents both scientific importance and natural beauty. With its strong ribbing, striking ornamentation, and secure provenance, it is an exceptional specimen for serious collectors, educators, and enthusiasts of Jurassic paleontology.