Ichthyosaur Humerus Fossil, Charmouth Mudstone Formation, Lyme Regis Jurassic Marine Reptile Bone from Dorset UK

Description

Genuine Ichthyosaur Humerus Fossil from the Jurassic Coast

This remarkable fossilised Ichthyosaur humerus (upper forelimb bone) originates from the famous Charmouth Mudstone Formation of Lyme Regis, Dorset, on England’s world-renowned Jurassic Coast. Preserved within Lower Jurassic marine sediments dating to the Sinemurian–Pliensbachian stages (approximately 199–183 million years ago), this authentic marine reptile bone represents a tangible piece of the ancient seas that once covered southern Britain.

The specimen is a carefully selected genuine fossil and the exact piece shown in the photographs is the specimen you will receive. It comes complete with a Certificate of Authenticity lifetime guarantee card confirming its status as a genuine fossil specimen. Please refer to the photographs for the full sizing and proportions of the fossil.

About Ichthyosaurs – Fast Marine Predators of the Jurassic Seas

Ichthyosaurs were highly specialised marine reptiles that thrived during the Mesozoic Era. Their name means “fish lizard,” reflecting their remarkable fish-like body shape, streamlined for speed in the ocean. Although reptiles, they evolved powerful flippers, a crescent-shaped tail, and large eyes adapted for hunting in marine environments.

Members of the order Ichthyosauria were apex predators of Jurassic seas, feeding primarily on fish, cephalopods such as ammonites and belemnites, and other marine organisms. Many species discovered around Lyme Regis belong to genera such as Ichthyosaurus and Stenopterygius, both commonly preserved in the Lower Jurassic formations of Dorset.

The Humerus – Key Limb Bone of the Foreflipper

The humerus is the principal bone of the forelimb and forms the upper segment of the Ichthyosaur’s powerful front flipper. In life, it articulated with the shoulder girdle and connected to the radius and ulna, forming a rigid paddle adapted for efficient swimming. Fossilised humeri from Ichthyosaurs often show distinctive flattened and expanded ends that helped support the paddle-like structure of the flipper.

This bone would have been an integral component of the animal’s locomotion, contributing to stabilisation and steering in the water while the tail provided most of the propulsion. Fossilised limb elements like this provide valuable insight into the biomechanics and evolutionary adaptations of marine reptiles during the Jurassic period.

Geological Context – Charmouth Mudstone Formation

The Charmouth Mudstone Formation is one of the most fossil-rich geological units in the United Kingdom. Deposited in a shallow marine environment during the Early Jurassic, these sediments consist mainly of dark grey mudstones and shales formed in a warm epicontinental sea.

Lyme Regis and the surrounding Dorset coastline have produced some of the most important marine reptile discoveries in palaeontology. Famous fossil collector Mary Anning made many of the earliest Ichthyosaur discoveries here in the early 19th century, helping establish the scientific understanding of prehistoric marine reptiles.

The sediments that preserved this specimen were deposited on the seabed where organic remains were gradually buried by fine mud. Over millions of years, mineralisation replaced the original bone material, preserving the fossil in remarkable detail.

Authenticity and Collectability

• Genuine fossil Ichthyosaur humerus

• Charmouth Mudstone Formation, Lower Jurassic

• Sinemurian–Pliensbachian stages (approx. 199–183 million years old)

• Collected from Lyme Regis, Dorset, UK

• Comes with a Certificate of Authenticity lifetime guarantee card

• The fossil shown in the photographs is the exact specimen you will receive

Specimens from Lyme Regis are highly sought after by collectors due to the site’s historical importance, exceptional fossil preservation, and the diversity of marine reptiles discovered there. This Ichthyosaur limb bone makes a superb addition to any fossil collection, natural history display, or educational geological collection, representing one of the most iconic marine reptiles of the Jurassic oceans.