Douvilleiceras mammillatum Fossil Ammonite Gault Clay Aptian Cretaceous Folkestone Kent UK Genuine Specimen

Description

Douvilleiceras mammillatum Fossil Ammonite

This listing is for a fine example of Douvilleiceras mammillatum, a fossil ammonite from the Gault Clay Formation at Folkestone, Kent, United Kingdom. This specimen dates to the Aptian stage of the Early Cretaceous Period, around 125–113 million years ago. Ammonites from Folkestone are highly prized by collectors due to their excellent preservation and their importance in defining Cretaceous ammonite biozones.

All of our fossils are 100% genuine specimens and include a Certificate of Authenticity. The photographs show the exact ammonite you will receive, with a 1 cm scale cube and rule squares provided to confirm precise sizing.

Geological Context and Age

The Gault Clay Formation is one of the most famous fossil-bearing deposits in the UK. Exposed along the cliffs and foreshore at Folkestone, it represents marine sediments laid down during the Aptian–Albian stages of the Early Cretaceous. These deposits formed in a shallow epicontinental sea that covered much of southern England and were connected to the Tethys Ocean, creating conditions ideal for ammonites and other marine invertebrates.

Douvilleiceras mammillatum is especially significant because it serves as the index species for the Douvilleiceras mammillatum Zone, a key subdivision of the Aptian stage. This makes specimens from Folkestone particularly valuable for correlating rock layers both locally and globally.

Morphology and Distinctive Features

Douvilleiceras mammillatum belongs to the family Douvilleiceratidae, within the superfamily Desmoceratoidea of the order Ammonitida. It is distinguished by its evolute, robust shell with whorls that display strong ornamentation. The ribs are bold and irregular, often thickened into tubercles (knob-like projections) across the flanks. These tubercles give the shell a distinctive textured appearance, making it easily recognisable compared to more finely ribbed ammonite species.

The venter (outer margin of the shell) is usually broad and rounded, with ribs crossing it strongly. These features may have functioned as both hydrodynamic adaptations and defensive reinforcements against predators. The morphology of Douvilleiceras mammillatum is so distinctive that it remains one of the most iconic ammonites of the Lower Cretaceous.

Scientific Importance

As the index fossil of the Aptian mammillatum Zone, this ammonite is a key reference point in the global stratigraphic record. Its presence allows geologists and palaeontologists to precisely date and correlate Aptian-age rocks across Europe and beyond.

Specimens of Douvilleiceras mammillatum also provide insight into ammonite evolutionary strategies during the Early Cretaceous. Their thick, tuberculate shells demonstrate adaptations to ecological pressures such as predation and changing marine environments. The Folkestone material, preserved in fine marine clays, is particularly well studied and features in numerous palaeontological publications.

Collector and Display Value

This Douvilleiceras mammillatum ammonite fossil from Folkestone is an excellent addition to any collection of Cretaceous fossils. Its bold ribbing and tuberculate ornamentation give it strong display value, while its importance as a biostratigraphic index fossil ensures lasting scientific relevance.

Collectors of British fossils, ammonites, or index species will particularly appreciate this piece. It also makes an excellent educational specimen, demonstrating key principles of ammonite morphology and stratigraphy.

Your Guarantee of Authenticity

• 100% genuine Douvilleiceras mammillatum ammonite fossil from Folkestone, Kent, UK
• Geological age: Aptian stage, Early Cretaceous (approx. 125–113 million years ago)
• Formation: Gault Clay Formation
• Index fossil for the Douvilleiceras mammillatum Zone
• Family: Douvilleiceratidae, Order: Ammonitida
• Distinctive features: bold ribs and tuberculate ornamentation
• Supplied with a Certificate of Authenticity
• Exact specimen shown in the photographs (not a stock image)
• Scale cube and rule squares = 1 cm for accurate size reference

This Douvilleiceras mammillatum fossil ammonite is both scientifically significant and visually impressive, making it a superb choice for collectors and enthusiasts of Cretaceous palaeontology.