Rare Mariella oechlerti Heteromorph Ammonite Fossil Lower Cenomanian Cretaceous Cher France Genuine Specimen

Description

Rare Mariella oechlerti Heteromorph Ammonite Fossil

This listing offers a rare Mariella oechlerti heteromorph ammonite fossil, dating from the Lower Cenomanian Stage of the Cretaceous period, discovered in Cher, France. A fine representative of the unusual heteromorph ammonites, it displays the striking non-planispiral shell form that sets these fossils apart from their more regularly coiled relatives. The specimen shown in the photographs is the exact piece you will receive. For scale, a 1 cm cube is included in the images, with full sizing details clearly visible. Every fossil we sell is a 100% genuine specimen and comes complete with a Certificate of Authenticity.

Geological Age and Context

The fossil comes from the Lower Cenomanian Stage, approximately 100–96 million years ago, which marks the beginning of the Late Cretaceous. The Cenomanian is a significant stage in Earth’s history, characterised by one of the highest global sea levels of the Phanerozoic, creating vast shallow seas across Europe and beyond. These warm marine environments supported diverse ecosystems, and ammonites were among the dominant inhabitants. Fossil-bearing sites in Cher, France, are well known for yielding important heteromorph ammonites such as Mariella oechlerti, providing paleontologists with key insights into the evolutionary and ecological dynamics of the time.

Scientific Classification

Mariella is a genus within the family Turrilitidae, superfamily Turrilitoidea, and order Ammonitida. The Turrilitidae are famous for their highly distinctive heteromorph ammonites, which developed shell forms that abandoned the typical coiled structure of most ammonites. Instead, these shells grew in irregular, helically twisted or loosely coiled patterns. Mariella oechlerti is a well-recognised species from French Cenomanian deposits, named and described in classic paleontological literature. It is an especially rare fossil that demonstrates the remarkable variability and evolutionary experimentation of Cretaceous ammonites.

Morphological Features

The shell of Mariella oechlerti is a fine example of heteromorph ammonite morphology. Its whorls are uncoiled into helically twisted, tower-like forms, creating a strikingly irregular appearance when compared with standard ammonites. The ribbing, which typically runs strongly across the shell, is another diagnostic feature, contributing to the fossil’s distinctiveness. These unique adaptations may have influenced the ammonite’s buoyancy and swimming style, possibly favouring a more passive, planktonic lifestyle in the mid-water column of the Cretaceous seas. This specimen shows these morphological traits clearly, making it not only scientifically valuable but also a striking display fossil.

Scientific and Collector Value

Heteromorph ammonites such as Mariella oechlerti are important to Cenomanian biostratigraphy, providing paleontologists with essential markers for dating and correlating marine strata. Their unusual shell designs also make them central to studies of ammonite evolution and adaptation, highlighting the extraordinary range of ecological niches occupied by these cephalopods. For collectors, a specimen of Mariella oechlerti from Cher is a true rarity, prized for its distinctive appearance, geological age, and provenance from one of France’s classic fossil regions.

Provenance and Authenticity

This specimen was collected in Cher, France, a locality renowned for its Cenomanian ammonite assemblages. It has been carefully selected for its scientific accuracy and preservation quality. Every fossil we offer is accompanied by a Certificate of Authenticity, giving full assurance of its provenance and genuineness. The specimen will be securely packaged and shipped with professional care.

This is a rare opportunity to own a Mariella oechlerti heteromorph ammonite fossil from the Lower Cenomanian of France, a specimen of both scientific and aesthetic significance that will make an exceptional addition to any fossil or ammonite collection.