Rare Fossil Heteromorph Uncoiled Ammonite (Stomohamites duplicatus) – Cenomanian, Upper Cretaceous, Glynde Sussex UK – Genuine + COA

Description

A rare heteromorph uncoiled ammonite (Stomohamites duplicatus), from the Cenomanian Stage of the Upper Cretaceous, collected at Glynde, Sussex, United Kingdom. This specimen is highly collectable, showing the unusual uncoiled morphology characteristic of heteromorph ammonites. The fossil pictured is the exact one you will receive, and it is supplied with a Certificate of Authenticity.

Fossil Type & Species:

• Type: Heteromorph Ammonite (extinct marine cephalopod)
• Species: Stomohamites duplicatus
• Order: Ammonitida
• Superfamily: Turrilitoidea
• Family: Hamitidae

Geological Context:

• Period: Cretaceous
• Epoch/Stage: Upper Cretaceous – Cenomanian (approx. 100.5 to 93.9 million years ago)
• Biozone: Associated with Cenomanian ammonite faunas including Mantelliceras mantelli and related taxa
• Formation: Chalk deposits of the Cenomanian stage (White Chalk Subgroup, southern England)
• Depositional Environment: Shallow marine chalk seas with calcareous sedimentation, excellent for fossil preservation

Locality:

• Region: Glynde, Sussex, United Kingdom

Morphology & Features:

• Uncoiled, irregular shell form typical of heteromorph ammonites
• Distinctive ribbing and ornamentation visible along the shell
• Unique morphology that differs from the more typical planispiral coiling seen in other ammonites
• Excellent preservation showcasing structural detail

Scientific Notes:

• Stomohamites duplicatus is a distinctive Cenomanian heteromorph ammonite
• First formally described in the 19th century during systematic studies of Cretaceous faunas in southern England
• Its unusual uncoiled form provides insight into ammonite evolutionary experimentation during the Late Cretaceous

Notable Details:

• Rare British heteromorph ammonite from a historically significant fossil locality
• Excellent preservation with clear ribbing and shell form
• 100% genuine, natural fossil – no restoration
• Scale Reference: Each square or cube = 1cm. Please see photographs for accurate sizing

Authenticity & Guarantee: All of our fossils are 100% genuine, responsibly sourced, and professionally curated. Each specimen is supplied with a Certificate of Authenticity. The fossil pictured is the exact one you will receive.

This Stomohamites duplicatus ammonite is a rare and scientifically important fossil from the Cenomanian of Sussex – an excellent addition for collectors, researchers, or natural history displays.