Proplanulites Fossil Ammonite Koenigi Zone Gowerianus Subzone Kellaways Formation Callovian Jurassic Maud Heath’s Causeway Wiltshire UK

Description

Authentic Proplanulites Fossil Ammonite from Wiltshire

This listing is for a genuine Proplanulites fossil ammonite from the Middle Jurassic deposits of Maud Heath’s Causeway, Wiltshire, UK. Sourced from the Koenigi Zone, Gowerianus Subzone of the Kellaways Formation, this specimen dates to the Callovian stage, around 165–163 million years ago. The fossil shown in the photographs is the exact specimen you will receive, with a 1 cm scale cube provided for accurate sizing.

Collected on 04 May 2024 by our field collectors Alister and Alison, this specimen has been expertly cleaned, prepped, and treated by Alison. Every fossil we sell is selected for its authenticity and quality, and this piece is accompanied by a Certificate of Authenticity, confirming it as a 100% genuine specimen.

Geological Context and Age

The Kellaways Formation represents marine deposits of the Middle Jurassic, laid down in shallow, warm seas that once covered much of southern England. Its fine-grained sandy and silty sediments preserve a variety of marine fossils, including ammonites, bivalves, and vertebrate remains.

The fossil originates specifically from the Koenigi Zone, Gowerianus Subzone, a well-defined stratigraphic interval within the Callovian stage. Ammonites such as Proplanulites are important index fossils for this horizon, allowing geologists to date and correlate layers across wide regions of Europe with precision.

Species Information – Proplanulites

Proplanulites belongs to the order Ammonitida, superfamily Perisphinctoidea, and family Perisphinctidae. This genus is characterised by its relatively compressed, planispiral shell with fine ribbing that radiates evenly across the whorls. Its whorl section is moderately involute, and the ornamentation is typically delicate compared with the more robust genera of the same period.

The morphological features of Proplanulites suggest it was a fast-swimming nektonic predator that thrived in open marine environments, feeding on small invertebrates and possibly juvenile cephalopods. Its presence in Callovian deposits makes it a key biostratigraphic marker, contributing to the detailed framework of Jurassic ammonite zones.

Fossil Features and Preservation

This specimen preserves the characteristic coiled form and ribbed ornamentation of Proplanulites. The whorl structure is clearly visible, with ribbing providing detail that reflects the shell’s natural growth pattern. Despite geological compression and wear, the essential diagnostic traits are intact, allowing reliable identification.

The fossil is preserved within its natural limestone matrix, offering both scientific context and aesthetic display value. The preparation process has carefully exposed the ammonite without overworking the stone, maintaining its authenticity as a natural specimen.

Collector and Scientific Significance

Ammonites such as Proplanulites are highly valued both for their beauty and for their scientific role as index fossils. Their restricted stratigraphic range makes them particularly useful in Jurassic biostratigraphy. This specimen, from the Gowerianus Subzone, is a fine example of a well-provenanced fossil with clear stratigraphic significance.

For collectors, this ammonite represents a rare opportunity to own a scientifically important and visually attractive specimen from a classic Jurassic locality. Its provenance from Maud Heath’s Causeway and strong association with the Koenigi Zone enhance both its scientific and collector appeal.

A Unique Jurassic Fossil from Wiltshire

This Proplanulites fossil ammonite is a genuine and well-prepared specimen from the Callovian of Wiltshire. With its geological significance, scientific importance, and display value, it is ideal for collectors, educators, and fossil enthusiasts alike. Supplied with a Certificate of Authenticity, it represents both a remarkable display piece and a scientifically valuable part of Britain’s Jurassic heritage.

All of our Fossils are 100% Genuine Specimens & come with a Certificate of Authenticity.