Acanthoceras rhotomagense Ammonite Fossil Cenomanian Cretaceous UK Authentic Specimen COA

Description

Acanthoceras rhotomagense Ammonite Fossil

This listing presents a striking Acanthoceras rhotomagense Ammonite Fossil, collected from the Lower Cenomanian stage of the Late Cretaceous in Sussex, United Kingdom. Dating to approximately 100–96 million years ago, this ammonite species is one of the most distinctive and scientifically significant fossils of the Cenomanian. The specimen is pictured with a 1 cm scale cube for accurate sizing, and the exact fossil shown is the one you will receive. Every fossil offered is 100% genuine and comes with a Certificate of Authenticity.

Geological Context – Lower Cenomanian of Sussex

This fossil originates from chalk and marl deposits in Sussex, a region of southern England renowned for its rich Cretaceous fossil record. The Cenomanian stage, marking the beginning of the Late Cretaceous, was a time of exceptionally high global sea levels. Much of Europe, including southern Britain, was covered by shallow epicontinental seas linked to the Tethys Ocean and proto-Atlantic systems.

These marine environments were nutrient-rich ecosystems teeming with ammonites, belemnites, inoceramid bivalves, and echinoids. The Sussex chalk deposits are a vital part of the Chalk Group, world-famous for their paleontological importance and for providing reference sequences for global stratigraphy. Fossils such as Acanthoceras rhotomagense are essential tools for understanding the Cenomanian period, its marine biodiversity, and its geological boundaries.

Species Overview – Acanthoceras rhotomagense

This specimen has been identified as Acanthoceras rhotomagense, belonging to the order Ammonitida, superfamily Acanthoceratoidea, and family Acanthoceratidae. The genus Acanthoceras is one of the most characteristic groups of Cenomanian ammonites, known for their ornate shells and robust ornamentation.

A. rhotomagense is notable for its strongly ribbed shell with coarse, evenly spaced ribs that often bifurcate across the flanks. Prominent ventrolateral tubercles form a striking row of nodules, giving the shell a highly textured appearance. These features make the species instantly recognisable and provide strength and hydrodynamic function, demonstrating evolutionary adaptations to open marine life.

This ammonite is especially important as it defines the Acanthoceras rhotomagense Biozone, a key interval within the Cenomanian stratigraphy. Its narrow stratigraphic distribution and easily recognisable morphology make it a classic index fossil, invaluable for correlating chalk sequences across Europe and beyond.

Paleontological Importance

The presence of Acanthoceras rhotomagense in Sussex deposits reflects the expansion of warm marine ecosystems during the Cenomanian transgression. Its abundance and distinctive shell form make it a cornerstone of Cretaceous biostratigraphy. Geologists and paleontologists use this species to define and correlate Cenomanian sequences, while its morphology provides insights into ammonite functional anatomy and ecological roles.

The heavily ornamented shell highlights evolutionary developments within the Acanthoceratidae, illustrating both structural adaptations for survival and diversification within this successful ammonite family.

Collector’s and Educational Value

This Acanthoceras rhotomagense ammonite fossil is a superb specimen for collectors of British ammonites and classic Cretaceous material. Its provenance from Sussex, United Kingdom, makes it historically and scientifically significant, as the region has long been central to studies of Cretaceous paleontology.

For teaching purposes, it offers an ideal example of Cenomanian ammonites, demonstrating both morphological features and their role as biostratigraphic markers. Its strong ribbing and striking tuberculation make it both a visually impressive display piece and a scientifically valuable fossil.

Guarantee of Authenticity

• 100% genuine Acanthoceras rhotomagense ammonite fossil
• Supplied with a Certificate of Authenticity
• The exact specimen shown in the photographs will be sent

This is a rare opportunity to acquire a beautifully preserved and scientifically important Acanthoceras rhotomagense Ammonite Fossil from the Lower Cenomanian of Sussex, United Kingdom, an exceptional addition to any fossil collection.