Ichthyosaur Vertebra Half Fossil Reptile Bone Jurassic Coast Lower Lias Black Ven Lyme Regis

Description

Ichthyosaur Vertebra Bone Half from the Jurassic Coast

This authentic Ichthyosaur Vertebra Bone Half originates from the iconic Jurassic Coast site at Black Ven, Lyme Regis, Dorset, UK, one of the most renowned fossil localities in the world. Your specimen was discovered by our field team, Alister and Alison, on 11 November 2025, and has been meticulously cleaned, prepared, and stabilised by Alison, ensuring excellent presentation and long-term preservation. The photographs show the exact fossil you will receive, accompanied by a 1cm scale cube to demonstrate accurate sizing. As always, your fossil comes with a Certificate of Authenticity, confirming it as a genuine, responsibly collected specimen.

Species Background: Ichthyosauria – Early Jurassic Marine Reptiles

Ichthyosaurs were fast, streamlined marine reptiles belonging to the order Ichthyosauria, dominant in the oceans during the Early Jurassic period. Their anatomy reflects specialised adaptations for life in open water, including powerful tails, elongated snouts, and large eyes suited for hunting in deep or low-light conditions. This vertebra represents a segment of the central axial column, which provided flexibility and strength during swimming. Even as a half section, the fossil retains classic ichthyosaur vertebral characteristics, offering a clear look at the internal and external structure of these remarkable reptiles.

The vertebra likely belonged to one of the common Early Jurassic forms known from the Lower Lias, where ichthyosaurs such as Ichthyosaurus and related genera were abundant. These animals thrived in marine ecosystems filled with ammonites, belemnites, fish, and other vertebrates, forming an essential part of the early Jurassic food web.

Geological Setting: Black Ven Marls, Lower Lias

This fossil comes from the Black Ven Marls, part of the Lower Lias Group, a sequence of sedimentary rocks deposited during the Hettangian–Sinemurian stages of the Early Jurassic Period approximately 196–190 million years ago. These marls and mudstones were laid down in a calm, offshore marine basin with limited oxygen circulation, creating ideal conditions for fossil preservation.

Black Ven is particularly famous for its fossil richness thanks to continuous coastal erosion that exposes fresh material year after year. Marine reptiles, ammonites, belemnites, and fish remains are commonly found here, but vertebrae—particularly well-preserved examples—remain highly desirable items for collectors. The fine-grained sediment of the marls supports the preservation of structural details, including the internal bone patterning evident in this half vertebra specimen.

Morphology and Diagnostic Features

This specimen exhibits the classic biconcave (amphicoelous) form typical of ichthyosaur vertebrae, even in half-section. The concave articulating surface reflects the reptile’s highly flexible spine, which enabled sinusoidal swimming motions. The cross-sectional view of this half vertebra offers an insightful look at internal bone texture, marrow cavities, and compact bone walls—details that are highly valued by those studying vertebrate palaeontology.

The outer surface shows natural curvature, radial striations, and structural reinforcement characteristic of the order Ichthyosauria. These biological traits helped the animal withstand the stresses of rapid acceleration and agile underwater manoeuvring. The half-section perspective provides both educational and display advantages, allowing detailed study of bone architecture not typically visible on complete vertebrae.

Depositional Environment and Palaeobiological Context

The Black Ven Marls formed in an ancient epicontinental sea where organic-rich muds accumulated under low oxygen conditions. This environment reduced decay and prevented scavenging, contributing to the exceptional fossil record preserved within the Lower Lias. Ichthyosaurs were apex predators in this ecosystem, hunting shoals of fish and cephalopods that thrived in the nutrient-rich waters.

The presence of a vertebra—especially one with such well-defined internal features—reflects the robust anatomy required for life in open marine settings. Despite the half-section nature of the specimen, it retains significant palaeobiological value and offers insight into the locomotion, skeletal structure, and evolutionary adaptations of these early Jurassic reptiles.

Collecting Significance and Display Appeal

This Ichthyosaur Vertebra Bone Half is an excellent specimen for educational, decorative, or scientific display. Its partial form provides a unique perspective on internal bone structure while still showcasing the iconic shape of ichthyosaur vertebrae. The clean preparation by Alison enhances surface details without altering natural features, resulting in a fossil that is both visually impressive and scientifically meaningful.

Fossils from Black Ven have played a pivotal role in the history of palaeontology since the days of Mary Anning, and specimens like this continue that legacy. This piece is a wonderful addition for collectors seeking authentic marine reptile material from one of the most important fossil sites in the world.

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