Rare Fossil Fish Reptile and Coprolite Large Block Aust Cliff Bristol Westbury Formation Upper Triassic UK Genuine Specimen with COA

Exceptional Fossil Fish, Reptile, and Coprolite Block from Aust Cliff, Upper Triassic, Bristol, UK

This outstanding Fossil Fish, Reptile, and Coprolite large block originates from the Westbury Formation, part of the Penarth Group, dating to the Upper Triassic Period (Rhaetian Stage, approximately 208–201 million years ago). It was discovered by our own team members, Alister and Alison, on 2 October 2025, at the world-renowned Aust Cliff, near Bristol, United Kingdom. The specimen has been carefully cleaned, prepared, and treated by Alison, revealing an extraordinary concentration of marine vertebrate remains that beautifully illustrate the complex ecosystems existing at the close of the Triassic.

Geological and Depositional Context

The Aust Cliff exposure represents one of Britain’s most important Late Triassic fossil localities and forms part of the Penarth Group, a transitional sequence that bridges the Triassic–Jurassic boundary. The Westbury Formation, specifically, is composed of dark grey to black laminated mudstones and shales deposited in a lagoonal to marginal marine environment, rich in vertebrate remains. These sediments were laid down in shallow, oxygen-poor waters, creating ideal conditions for fossil preservation.
During this time, the region that is now southwest England was part of a warm, low-latitude coastal system bordering the ancient supercontinent Pangaea. The seas were teeming with life — including fishes, early marine reptiles, and invertebrates — yet subject to periodic die-offs caused by fluctuating salinity and sea levels. Fossil accumulations like this block provide rare snapshots of those ecological shifts, often interpreted as mass mortality or storm-wash deposits known as bone beds.

Fossil Composition and Features

This specimen contains a mixture of fossilised fish remains, reptile bone fragments, and coprolites (fossilised dung). The fish material likely represents species from families such as Saurichthyidae or Palaeoniscidae, both typical of Rhaetian marine faunas. Small scales, teeth, and vertebral fragments may be visible, showing the shimmering detail of ancient bone texture preserved in the sediment. The reptile remains could belong to early marine reptiles such as ichthyosaurs or thalattosaurs, whose isolated bones are often found scattered within the same horizon.
The coprolites, distinct by their spiral or cylindrical forms, add further fascination — physical evidence of the feeding behaviour of prehistoric predators. Their inclusion in the same block as skeletal material gives direct insight into the trophic dynamics of the Upper Triassic seas.

Scientific Importance and Collectability

The Westbury Formation bone beds have been studied for over a century and continue to provide invaluable data on faunal turnover at the end of the Triassic, immediately preceding the great extinction that opened the Jurassic. This block exemplifies the vertebrate diversity and taphonomic complexity of the site, with material representing multiple species preserved in a single slab. Specimens like this are highly prized for research and display, illustrating both scientific and visual appeal.
Such multi-fossil association blocks are uncommon on the open market, particularly those from well-documented localities like Aust Cliff. Their mix of fish, reptilian, and coprolitic material encapsulates the environmental richness and biological interactions of the time.

Condition, Provenance, and Authenticity

This is a 100% genuine fossil specimen, collected and prepared by our experienced team. The block has been professionally stabilised and cleaned to highlight key fossil features while retaining the natural integrity of the matrix. The photograph shows the actual specimen you will receive, not a representative image. Each piece is selected for its scientific and aesthetic quality.
Included with the fossil is a Certificate of Authenticity, verifying the specimen’s geological age, formation, and provenance.

Details at a Glance

• Fossil Type: Fish, Reptile, and Coprolite block

• Formation: Westbury Formation, Penarth Group

• Age: Upper Triassic (Rhaetian Stage, ~208–201 million years ago)

• Locality: Aust Cliff, Bristol, United Kingdom

• Discovered by: Alister and Alison on 02 October 2025

• Prepared by: Alison

• Depositional Environment: Marginal marine to lagoonal sediments

• Condition: Professionally cleaned, stabilised, and display-ready

• Scale: Cube = 1 cm (see photo for full sizing)

• Included: Certificate of Authenticity

A Unique Window into the Late Triassic World

This Fossil Fish, Reptile, and Coprolite block from Aust Cliff captures the dynamic life and depositional history of Britain’s prehistoric seas. Both a scientifically valuable specimen and a visually striking natural artefact, it is a remarkable piece of the Earth’s deep history, beautifully prepared and preserved for collectors, educators, and enthusiasts of palaeontology.