Asthenoceras Grammoceras nannodes Ammonite Fossil Lower Bajocian Jurassic UK Gem | Tilton Leicestershire Rare Specimen

Description

Genuine Asthenoceras nannodes Ammonite Fossil

This carefully chosen fossil is a genuine Asthenoceras (Grammoceras) nannodes ammonite from Tilton in Leicestershire, UK. It dates to the Lower Bajocian stage of the Middle Jurassic. The photographs show the actual specimen you will receive, allowing its natural preservation, shape, colour, matrix and visible fossil detail to be assessed before purchase. Please refer to the photographs for complete sizing and scale.

Lower Bajocian Geology

The Bajocian is an early stage of the Middle Jurassic and dates to approximately 170 to 168 million years ago. During this interval, much of Britain was covered by warm, shallow marine waters. Sediment accumulated across a broad shelf in environments influenced by changing sea level, currents, storms and local sediment supply. Over time, burial and mineralisation transformed these deposits into the rocks that now preserve ammonites and other marine fossils.

Ammonites are particularly useful in Jurassic geology because their lineages evolved rapidly and many species were distributed over wide marine areas. Palaeontologists compare characteristic ammonite assemblages to correlate strata and divide stages into narrower biozones. A specimen with a recorded species and locality therefore provides both display appeal and meaningful geological context.

Asthenoceras and Grammoceras

Asthenoceras is an extinct ammonite genus within the order Ammonitida. The parenthetical name Grammoceras records an associated taxonomic placement used with this identification. Ammonites were marine cephalopods related to living squid, octopus and nautilus. Their coiled shells were divided internally into chambers. The animal occupied the final body chamber while sealed earlier chambers helped regulate buoyancy in the water column.

Identification of Jurassic ammonites draws on the whole preserved form. Specialists examine the degree of coiling, whorl proportions, umbilical width, ribbing and the shape of the outer margin. Asthenoceras nannodes is a small and distinctive named form from Lower Bajocian strata. The fossil may preserve shell material, mineral replacement, an external impression or an internal mould formed when sediment filled the shell. Matrix, worn areas, fractures and irregular surfaces are natural evidence of fossilisation and geological exposure rather than manufactured defects.

Tilton, Leicestershire

Tilton and the surrounding area of Leicestershire lie within a region where Jurassic rocks have produced scientifically valuable fossil material. Inland localities are important because they complement the better-known coastal exposures and reveal how marine strata continue beneath the modern landscape. Fossils from Tilton document the animals that inhabited the Jurassic sea over central England and allow the local succession to be compared with Bajocian rocks elsewhere in Britain and Europe.

The specimen’s Tilton provenance adds specific collecting interest. It represents an extinct cephalopod that lived in a marine ecosystem alongside other ammonites, belemnites, bivalves, brachiopods and diverse invertebrates. After the animal died, burial on the seabed protected part of its shell long enough for fossilisation to occur. Later uplift, erosion and discovery brought that record of the Jurassic sea back to the surface.

Actual Specimen for Collection or Display

You will receive the exact fossil shown in the photographs. Its named identification, Lower Bajocian age and Leicestershire locality make it suitable for a specialist ammonite collection, geological study, educational display, natural-history cabinet or an unusual gift for a fossil enthusiast.

Certificate of Authenticity

The fossil includes a generic Certificate of Authenticity card carrying a lifetime guarantee of authenticity. Handle it carefully and avoid soaking, harsh chemicals, excessive humidity and sudden temperature changes. Support the specimen securely when displaying it so its natural edges, matrix and any exposed shell detail remain protected.