Juvenile Ichthyosaur Femur Bone Fossil Reptile Lower Lias Black Ven Marls Lyme Regis Dorset UK

Description

Authentic Juvenile Ichthyosaur Femur Bone Fossil

This exceptional specimen is a Juvenile Ichthyosaur Femur Bone, discovered within the Black Ven Marls, Lower Lias Formation along the Jurassic Coast at Black Ven, Lyme Regis, Dorset, UK. It dates from the Lower Jurassic period (approximately 195–200 million years ago), a time when the warm shallow seas of early Jurassic England teemed with marine reptiles. This fossil provides a rare glimpse into the skeletal anatomy of a young Ichthyosaur, one of the most iconic marine predators of the Mesozoic era.

Your specimen was discovered by our team members, Alister and Alison, on 20 October 2025, and has been carefully cleaned, prepared, and treated by Alison to preserve its fine structural details. The photo shown is of the actual fossil you will receive, ensuring transparency and authenticity for collectors and enthusiasts alike.

Geological Context and Origin

The fossil was found in the Black Ven Marls Member of the Charmouth Mudstone Formation, part of the world-renowned Jurassic Coast World Heritage Site. The Black Ven area, situated between Charmouth and Lyme Regis, is globally famous for its rich fossil beds, particularly of marine reptiles and ammonites.

These deposits were laid down in a low-energy, offshore marine environment with fine-grained clays and silts that allowed for remarkable preservation. Periodic oxygen-poor conditions inhibited decay, enabling the preservation of bones and other organic material in fine detail. The Black Ven Marls represent part of the Sinemurian–Pliensbachian stages of the Early Jurassic, a key interval in the evolution of marine reptile lineages.

Scientific Classification

• Kingdom: Animalia
• Phylum: Chordata
• Class: Reptilia
• Order: Ichthyosauria
• Family: Ichthyosauridae
• Age: Early Jurassic (Lower Lias, Sinemurian–Pliensbachian)
• Formation: Black Ven Marls, Charmouth Mudstone Formation
• Locality: Black Ven, Lyme Regis, Dorset, UK

Ichthyosaurs were fully aquatic reptiles, superficially resembling modern dolphins, with elongated bodies, powerful tails, and paddle-like limbs adapted for life in the open sea. The femur, part of the rear flipper, shows the early ossification typical of a juvenile specimen, offering insights into growth and limb morphology during early development.

Morphology and Preservation

This juvenile femur displays the characteristic robust yet tapered structure of the Ichthyosaur limb bone, with smooth cortical bone and subtle curvature indicative of streamlined adaptation for swimming. The preservation quality is outstanding, retaining the natural shape and fine bone texture.

Pyritic mineralisation typical of the Black Ven Marls gives the fossil a subtle metallic sheen, while stabilisation and conservation treatment have ensured durability. The scale cube (1 cm) shown in the photograph provides accurate proportioning — full measurements are available in the listing images.

Palaeobiological and Evolutionary Significance

Ichthyosaurs are among the earliest and most successful marine reptiles, having evolved from terrestrial ancestors into highly efficient oceanic predators. Their streamlined form, large eyes, and ability to give live birth at sea illustrate remarkable evolutionary adaptation. Juvenile specimens such as this femur are particularly significant to science, as they help palaeontologists understand growth stages, limb development, and bone histology within the Ichthyosaur lineage.

The specimen likely belonged to an individual less than a meter in length, suggesting it was either a neonate or very young juvenile. Its preservation within the Black Ven Marls highlights the exceptional depositional conditions that made Lyme Regis one of the most scientifically important fossil sites in the world.

Authenticity and Provenance

All of our fossils are 100% genuine specimens and come with a Certificate of Authenticity. Each piece is responsibly sourced and hand-prepared by our team to the highest standards. No artificial enhancements are applied — only professional cleaning and consolidation to stabilise and preserve natural integrity.

This Juvenile Ichthyosaur Femur Bone is a remarkable example of British Jurassic heritage, combining historical, scientific, and aesthetic value. A genuine piece of prehistoric life from the legendary Jurassic Coast, perfect for collectors, educators, or anyone fascinated by the ancient seas that once covered Dorset.