RARE Trace Fossil – Entobia cretacea Sponge Borings, Upper Chalk Cretaceous, Hayling Island Hampshire UK – Authentic Fossilised Substrate

Description

Offered here is a scientifically important trace fossil specimen of Entobia cretacea, a structure formed by burrowing sponges in carbonate substrates. This example comes from the Upper Chalk Formation of the Cretaceous Period, collected at West Side Beach, Hayling Island, Hampshire, UK.

Entobia is a type of ichnofossil (trace fossil) created by the bioerosive activity of clionaid sponges, which bored into hard calcareous substrates such as shells, limestone cobbles, or carbonate hardgrounds. This specimen preserves these classic boring structures in exceptional detail.

Geological and Scientific Details:

• Fossil Type: Trace fossil (ichnofossil)
• Name: Entobia cretacea
• Produced by: Clionaid sponges (bioerosion)
• Age: Late Cretaceous, Upper Chalk (approx. 89–66 million years ago)
• Location: Hayling Island, West Side Beach, Hampshire, United Kingdom
• Geological Stage: Typically falls within the Campanian-Maastrichtian interval of the Upper Cretaceous
• Depositional Environment: Shallow marine carbonate platform with abundant benthic life and stable substrates suitable for sponge colonisation

Morphology & Features:

• The borings of Entobia cretacea appear as a network of small, interconnected chambers and galleries within the host rock or fossil
• These burrows were originally lined by living sponge tissue and later fossilised when infilled with sediment or calcite
• Preserved borings are visible as clustered dots, tubes, or honeycomb-like textures depending on sectioning and preservation

Scientific Importance:

• Entobia provides crucial information about paleoecology, sponge-sediment interactions, and hard substrate colonisation in marine settings
• Useful for reconstructing Cretaceous marine ecosystems, especially relating to benthic encrusting communities
• Common in hardgrounds and bored fossil shells, yet complete and well-preserved examples like this are rare and valuable

This specimen is presented with a 1 cm scale cube (see photos for size and proportions). You will receive the exact item shown in the images. Carefully selected for its clear and scientifically important features.

Authenticity Guaranteed: All fossils are 100% genuine specimens and come with a Certificate of Authenticity. This trace fossil is ideal for display, educational use, or inclusion in a serious ichnological or Cretaceous fossil collection.

An unusual and valuable insight into ancient life and the hidden history of bioerosion on the ancient sea floor.