Diacalymene Trilobite Fossil Nodule Positive Negative Halves Kem Kem Beds Morocco Aptian Cretaceous Tegana Formation Genuine Specimen COA

Description

Authentic Diacalymene Trilobite Fossil

This listing features a rare Diacalymene trilobite fossil preserved within a natural nodule, displaying both the positive and negative halves. The specimen originates from the Kem Kem Beds, Tegana Formation, Aptian stage of the Cretaceous period, within the famous Kem Kem Basin of Morocco. Such nodules are highly prized by collectors, as they preserve the trilobite in exquisite detail, with both impressions offering insight into the morphology of this ancient arthropod. Each photo provided shows the actual specimen you will receive, with a 1 cm scale cube included for accurate sizing.

Geological Context – Kem Kem Beds, Cretaceous of Morocco

The Kem Kem Beds are among the most significant fossil-bearing deposits in North Africa. They date to the Aptian stage of the Early Cretaceous, approximately 125–113 million years ago, and are part of the Tegana Formation. These strata represent a fluvial environment, consisting of sandstones and mudstones deposited by ancient rivers and floodplains. The Kem Kem Basin is world-renowned for yielding a diverse array of vertebrate and invertebrate fossils, including dinosaurs, crocodilians, fish, and arthropods. The preservation of a trilobite such as Diacalymene in this context is unusual and adds a rare dimension to the palaeontological record of the region.

Trilobite Overview – Diacalymene

The genus Diacalymene belongs to the order Phacopida, family Calymenidae, a lineage of trilobites that first appeared in the Ordovician and are typically found in Palaeozoic deposits. Their occurrence in Cretaceous strata of the Kem Kem Basin is significant, as it represents a reworked specimen transported into younger sediments. Diacalymene trilobites are characterised by their semi-elliptical cephalon, distinct axial furrows, and well-developed thoracic segments. The fossil in this nodule clearly displays these morphological traits, providing both scientific and aesthetic value.

Morphological Features and Preservation

The nodule contains both halves of the fossil—the positive (body fossil) and the negative (natural mould)—allowing the trilobite to be studied from multiple perspectives. The cephalon (head shield), thorax, and pygidium (tail piece) are clearly visible, showing the segmented exoskeleton typical of Diacalymene. Fine surface details are preserved, capturing the natural ridges and curvature of the trilobite’s body. This type of preservation is especially valuable to collectors and researchers, as it offers a near-complete representation of the trilobite’s anatomy.

Depositional Environment and Significance

Although trilobites had gone extinct by the end of the Permian period, specimens such as this are sometimes found within younger deposits, having been reworked from earlier Palaeozoic strata and deposited within Cretaceous formations such as the Kem Kem Beds. This highlights the dynamic geological history of the region, where older fossil material was transported and embedded within later sedimentary layers. Such occurrences provide a fascinating record of both ancient life and the processes of sedimentary reworking.

Collectible and Educational Value

A Diacalymene trilobite nodule with both positive and negative halves is a superb addition to any fossil collection. It is both a scientifically important specimen and an aesthetically striking display piece, offering a direct connection to the evolutionary history of arthropods. Collectors, students of palaeontology, and educational institutions will all appreciate the unique insights this fossil provides.

Provenance and Guarantee

As with all of our specimens, this fossil is 100% genuine and comes with a Certificate of Authenticity. The fossil has been carefully selected for quality, ensuring that the piece you receive represents both the beauty and scientific significance of this rare find from Morocco.

A Rare Trilobite Fossil from Morocco

This Diacalymene trilobite fossil nodule from the Kem Kem Beds represents an extraordinary opportunity to own a piece of palaeontological history. With both positive and negative halves preserved, it offers exceptional detail and display potential, making it a prized addition to any serious fossil collection.