Chondroceras evolvensis Microconch Ammonite Fossil France with COA

Description

Genuine Chondroceras Ammonite Fossil

This genuine ammonite fossil is identified as a microconch of Chondroceras evolvensis from Bajocian rocks in Calvados, Normandy, France. It is a carefully selected Middle Jurassic specimen with useful species, age, and locality information, making it suitable for an ammonite collection, geological display, educational resource, or natural-history gift. The photographs show the exact fossil offered for sale, so the specimen pictured is the specimen you will receive.

Chondroceras evolvensis is an extinct marine cephalopod known from the Jurassic. Its coiled shell records the growth of an animal that lived in an ancient sea long before modern Normandy took shape. The identification as a microconch refers to the smaller adult form recognised within some ammonite species. Microconchs and larger macroconchs are commonly interpreted as different adult forms of the same biological species, often associated with sexual dimorphism, although they were historically sometimes described separately.

Bajocian Age and Jurassic Geology

The fossil dates from the Bajocian Stage of the Middle Jurassic Period. This interval was marked by changing marine environments and a rich diversity of ammonites. Their rapid evolution and wide geographical distribution made ammonites particularly valuable to geologists: characteristic forms can help correlate sedimentary layers and establish their relative ages.

Calvados in Normandy contains important Jurassic sedimentary sequences formed when the region lay beneath or beside warm shallow seas. Sediment accumulated on the sea floor, and shells could become buried before being compressed, mineralised, and preserved through geological time. The natural matrix, mineral colour, and surface texture visible on this specimen reflect that long history of burial and fossilisation.

Shell Form and Collectable Features

Chondroceras ammonites are valued for their compact coiling and distinctive ornamentation. Please examine the photographs for the features preserved on this individual, including the visible whorls, ribbing, shell outline, and areas of natural matrix. The shell originally contained a series of internal chambers. As the ammonite grew, it constructed new chambers and lived in the final body chamber, while older chambers contributed to buoyancy control.

The microconch form is especially interesting because it represents a mature but relatively small shell rather than simply a juvenile example. Adult modifications in ammonites can provide evidence about growth and life history. Where visible, the rib pattern and changes around the outer whorl are important morphological details used when comparing related forms. Preservation varies naturally across fossil shells, and any small breaks, irregular surfaces, or changes of colour are part of the actual geological specimen.

A Documented Fossil from Normandy

This fossil combines a named species, a recognised adult form, a Middle Jurassic stage, and a classic French region. That information gives the specimen context beyond its visual appeal. It can complement a collection organised by ammonite genus, Jurassic stage, European locality, or shell morphology. It also provides a useful starting point for discussing ammonite growth, palaeontology, biostratigraphy, and ancient marine ecosystems.

Exact Specimen, Size and Authenticity

Full sizing is shown in the photographs, which provide the clearest scale and condition information for this individual piece. The images are not representative stock pictures. They show the exact Chondroceras evolvensis microconch ammonite fossil supplied to the buyer.

This is a genuine fossil specimen and includes a generic Certificate of Authenticity card with a lifetime guarantee. It has been carefully chosen for its identifiable form, Bajocian age, Normandy provenance, and natural character. The fossil will make a distinctive addition to a cabinet collection, study set, office display, or gift for someone interested in Jurassic life and authentic fossils.