Rare Peronoceras subarmata Fossil Ammonite Jurassic Toarcian Ilminster Somerset UK

Description

Rare Peronoceras subarmata Fossil Ammonite from Ilminster, Somerset

This listing features a rare Peronoceras subarmata fossil ammonite from the Toarcian stage of the Jurassic period, discovered near Ilminster, Somerset, United Kingdom. This exceptional specimen is a fine example of an ammonite from the world-renowned Ilminster Beds, a classic British fossil locality celebrated for its richly preserved Jurassic marine fauna. The photographs show the exact fossil you will receive, with a 1 cm scale cube included for accurate size reference. All of our fossils are 100% genuine specimens and are supplied with a Certificate of Authenticity.

Geological Setting – Toarcian, Jurassic

This fossil dates back to the Toarcian stage of the Early Jurassic, approximately 182–174 million years ago. During this time, Ilminster and much of southern England lay beneath warm, shallow seas. The sediments that accumulated in this region formed the Lower Lias and overlying Ilminster Clay Beds, which are particularly famous for their superb preservation of ammonites, belemnites, bivalves, and marine reptiles.

The Toarcian is also an important geological interval due to the Toarcian Oceanic Anoxic Event, a time of significant climatic and environmental change. Fossils from this period, including Peronoceras subarmata, provide vital insights into how marine life adapted during these shifts.

Species and Taxonomy

• Genus: Peronoceras
• Species: subarmata
• Order: Ammonitida
• Superfamily: Hildoceratoidea
• Family: Hildoceratidae

Peronoceras subarmata belongs to the Hildoceratidae, a family of ammonites characterised by their ribbed and tuberculate shells. Ammonites of this group are widely used in stratigraphic studies as index fossils, helping geologists to precisely date Jurassic rock layers across Europe.

Morphological Features

The Peronoceras subarmata ammonite has a number of distinctive features that set it apart:

• Shell form: Evolute, with exposed inner whorls clearly visible.
• Ribbing: Bold, radiating ribs crossing the whorl, often accented by tubercles or nodal swellings.
• Whorl profile: Thick and rounded, creating a sturdy, robust shell form.
• Ornamentation: The ribbing and tuberculation provide a striking and highly recognisable appearance, making it a particularly desirable collector’s piece.

These features not only make Peronoceras subarmata visually impressive but also scientifically important in helping to identify precise stratigraphic intervals.

Stratigraphy and Biozone Importance

Peronoceras subarmata is closely tied to the subarmatum Biozone of the Toarcian. Its distribution across European deposits makes it a key biostratigraphic marker species, essential for correlating marine sediments of this age. The presence of such ammonites within the Ilminster succession provides important evidence for Jurassic palaeontology and stratigraphy.

Collector and Scientific Value

• Collectors value this ammonite for its rarity and distinctive morphology.
• Scientists and educators appreciate its role as a key index species for the Toarcian.
• For display, the bold ribbing and nodal features create an eye-catching fossil that stands out as a centrepiece in any collection.

Authenticity and Guarantee

All our fossils are responsibly sourced and are 100% genuine specimens. This Peronoceras subarmata ammonite from Ilminster has been carefully chosen for its quality and authenticity. Each specimen comes with a Certificate of Authenticity, guaranteeing provenance and peace of mind.

Key Information at a Glance

• Fossil Type: Ammonite
• Species: Peronoceras subarmata
• Geological Age: Toarcian, Jurassic (~182–174 million years old)
• Locality: Ilminster, Somerset, United Kingdom
• Family: Hildoceratidae
• Order: Ammonitida
• Condition: Natural fossil with ribbing and tuberculate features preserved
• Authenticity: Guaranteed with Certificate of Authenticity

This rare Peronoceras subarmata ammonite from Ilminster, Somerset is both scientifically important and visually stunning, offering collectors, researchers, and enthusiasts an authentic and historic piece of Britain’s Jurassic heritage.