RARE 12″ Acompsoceras bochumensis Fossil Chalk Ammonite Lower Cenomanian Cretaceous Lewes Kent

Description

Rare Large Acompsoceras bochumensis from the Lower Cenomanian

This exceptional 12-inch Acompsoceras bochumensis fossil ammonite is a rare and impressive specimen from the Lower Cenomanian stage of the Cretaceous period. Discovered in the historic Southerham Grey Pit near Lewes, Kent, England, this ammonite represents one of the more striking marine fossils from the UK chalk deposits. Its size, preservation, and provenance make it a highly desirable addition for serious collectors, educators, and natural history enthusiasts alike. The fossil pictured is the exact specimen you will receive, chosen for its detail and display appeal.

Geological Age & Provenance

The Lower Cenomanian stage dates to approximately 100.5 to 97 million years ago, during a time when much of what is now southern England lay beneath a warm, shallow epicontinental sea. The Southerham Grey Pit is part of the famous Lewes Chalk sequence, known for its fossiliferous chalk beds rich in marine invertebrates. This chalk formed in a calm, open marine environment, where fine carbonate sediments slowly accumulated on the seafloor, preserving the remains of organisms such as ammonites, belemnites, and marine reptiles.

Species Information & Taxonomy

Acompsoceras bochumensis is a member of the family Acanthoceratidae, within the superfamily Acanthoceratoidea, order Ammonitida. It is characterised by a robust, evolute shell with moderately wide whorls, strong ribbing, and distinctive tuberculation along the flanks. In larger specimens such as this one, the ribs and tubercles remain prominent, giving the shell a striking, textured appearance. The venter (outer curve of the shell) typically displays broad, rounded ribs that continue uninterrupted, a feature that helps with species identification.

Morphology & Notable Features

This specimen displays well-preserved ribbing and defined tubercles, which are key morphological traits of Acompsoceras bochumensis. The large size of this ammonite suggests it was a fully mature adult, offering insights into the life cycle of the species. The chambered shell, or phragmocone, would have allowed the living animal to regulate buoyancy, making it an active predator capable of moving freely through the water column.

Paleoenvironment & Significance

During the Cenomanian, the chalk seas of southern England were rich ecosystems, supporting a diverse range of marine life. Ammonites like Acompsoceras were important predators, feeding on smaller molluscs and crustaceans. The wide geographic distribution of this genus, combined with its relatively short stratigraphic range, makes it a valuable index fossil for dating Cenomanian marine deposits. Fossils from the Southerham Grey Pit are prized for their scientific value as well as their aesthetic qualities.

Collector Value

• Size: Large 12″ specimen, making it a statement display piece.
• Preservation: Strong surface detail with visible ribbing and tuberculation.
• Origin: Southerham Grey Pit, Lewes, Kent – a well-documented and significant UK fossil locality.
• Authenticity: 100% genuine, supplied with a Certificate of Authenticity.

This rare Acompsoceras bochumensis fossil is not only a captivating display item but also an important specimen for understanding Cretaceous marine life in the chalk seas of England. Its combination of size, scientific significance, and provenance makes it an outstanding acquisition for any fossil collection.