Belemnite Fossil Lower Lias Jurassic Seatown Dorset UK 30–60mm Genuine Specimen with Certificate of Authenticity

Description

Overview – Genuine Belemnite Fossil from Seatown, Dorset

This listing offers a 100% genuine Belemnite fossil, collected from the Lower Lias deposits of the Jurassic Coast near Seatown, Dorset, UK. Each fossil measures approximately 30–60mm, with the photos showing an example of the high-quality specimen you will receive. Beautifully preserved and naturally shaped, these belemnites are excellent additions to fossil collections, educational sets, or displays. Every specimen is accompanied by a Certificate of Authenticity, and a 1 cm scale cube is included in the images for size reference.

What Are Belemnites? – Ancient Cephalopods of the Jurassic Seas

Belemnites were extinct marine cephalopods related to modern squid and cuttlefish, belonging to the order Belemnitida. Unlike ammonites, which possessed coiled external shells, belemnites had internal hard parts. The portion most commonly preserved as a fossil is the rostrum, a bullet-shaped internal structure composed primarily of calcite. This rostrum provided balance and buoyancy control, helping belemnites move swiftly through ancient seas.

During the Early Jurassic, belemnites thrived in warm, shallow marine environments that covered much of what is now southern England. They were active predators, feeding on small fish, crustaceans, and other marine invertebrates, using their hook-lined arms to catch prey.

Geological Context – Lower Lias, Early Jurassic

The Lower Lias formation dates to the Hettangian–Sinemurian stages of the Early Jurassic (approximately 200–190 million years ago). The sediments around Seatown and the surrounding Dorset coast are part of the world-renowned Jurassic Coast UNESCO World Heritage Site, famous for its continuous sequence of fossil-rich coastal cliffs.

The Lower Lias is composed primarily of mudstone, shale, and limestone, deposited in a calm, shallow sea. These sediments provided ideal conditions for fossilisation, burying marine organisms gently and mineralising their remains over millions of years. Belemnite rostra are abundant in these beds and often retain excellent preservation due to their dense, mineral-rich composition.

Morphology and Distinguishing Features of the Specimen

Your belemnite fossil displays several classic structural traits, including:

• Solid, cylindrical rostrum, tapering to a pointed end

• Smooth or subtly grooved surfaces, depending on natural sediment wear

• Calcite-rich internal structure, visible on broken surfaces

• Natural Jurassic mineral staining, giving hues of cream, beige, grey, or brown

• Compact size (30–60mm), ideal for display or handling

These rostra are extremely durable, making them some of the most commonly preserved cephalopod fossils. Their distinctive torpedo-like shape makes them instantly recognisable to collectors and fossil enthusiasts.

Depositional Environment – Jurassic Marine Ecosystem

During the Early Jurassic, the area now known as Seatown was submerged beneath a warm, shallow inland sea. Marine life flourished, including belemnites, ammonites, fish, and early marine reptiles such as ichthyosaurs. Fine muddy sediments accumulated slowly on the seafloor, preserving the remains of cephalopods and other marine organisms.

Low-oxygen environments within the mud reduced decay and scavenging, allowing hard parts like belemnite rostra to fossilise readily. As erosion continues along the coast today, these fossils are washed from the cliffs and exposed on the beach for collectors to find.

Scientific and Collector Appeal

Belemnites are scientifically important fossils because they help researchers understand:

• Early Jurassic marine ecosystems

• Cephalopod evolution and diversity

• Ancient ocean temperature patterns (via chemical analysis of their calcite)

• Predator–prey relationships in Jurassic seas

For collectors, belemnites are classic British fossils that hold significant educational and aesthetic appeal. Their smooth, elegant shapes and natural variation make them ideal for study, display, or gifting to fossil enthusiasts.

Product Details

• Fossil Type: Belemnite Rostrum

• Geological Formation: Lower Lias

• Geological Age: Early Jurassic (Hettangian–Sinemurian)

• Locality: Seatown, Jurassic Coast, Dorset, UK

• Size: 30–60mm (see photos for scale)

• Authenticity: 100% genuine specimen with Certificate of Authenticity

• Photograph: Shows an example of the specimen quality you will receive

• Scale Cube: 1 cm included for accurate measurement

This genuine belemnite fossil is a classic example of Early Jurassic marine life from the iconic Dorset coastline—an ideal addition to any fossil collection, educational display, or natural history enthusiast’s cabinet.