Geocoma libanotica Fossil Brittle Star Cenomanian Upper Cretaceous Hakel Lebanon

Description

Geocoma libanotica Fossil Brittle Star – Cenomanian, Upper Cretaceous, Hakel, Lebanon

This exceptional Geocoma libanotica Fossil Brittle Star is an authentic and beautifully preserved specimen from the Sannine Formation, found in the world-renowned Hakel Quarry, near Byblos, Lebanon. Dated to the Cenomanian Stage of the Upper Cretaceous, approximately 98–95 million years ago, this fossil captures the delicate elegance of one of Earth’s earliest known brittle stars.

The fossil is 100% natural as found, preserved in fine-grained limestone that records even the most intricate details of the arms and central disc. The photo shows the actual specimen you will receive, supplied with a Certificate of Authenticity confirming its origin, species, and geological age. Each specimen is carefully chosen for clarity, completeness, and visual appeal — a true piece of natural history from the ancient seabeds of the Tethys Ocean.

Geological and Stratigraphic Context

This fossil originates from the Hakel area, part of the Sannine Formation, a sequence of marine limestones deposited during the Cenomanian Stage of the Upper Cretaceous. Approximately 98 million years ago, this region lay beneath the warm, shallow waters of the Tethys Ocean, a vast tropical sea that connected what are now Africa, Asia, and Europe.

The depositional environment of Hakel was calm, low-energy, and anoxic — lacking in oxygen at the seafloor. These conditions prevented scavenging and decomposition, allowing marine organisms to settle gently on the seabed before being rapidly buried by fine carbonate muds. Over millions of years, these sediments lithified into limestone, preserving fossils with remarkable detail.

The Sannine Formation is world-famous for its Konservat-Lagerstätte preservation, which captures delicate marine life such as brittle stars, fish, crustaceans, and plants with extraordinary fidelity. Fossils from this formation are crucial to our understanding of Cretaceous marine ecosystems and the biodiversity of the Tethys Ocean.

Taxonomy and Scientific Classification

• Fossil Type: Brittle Star (Echinoderm)
• Scientific Name: Geocoma libanotica
• Phylum: Echinodermata
• Class: Ophiuroidea
• Order: Ophiurida
• Family: Ophiolepididae
• Genus: Geocoma
• Geological Stage: Cenomanian (Upper Cretaceous)
• Formation: Sannine Formation
• Locality: Hakel Quarry, Byblos District, Lebanon

Geocoma libanotica is one of the most iconic brittle star species from the Lebanese Cretaceous. Its name derives from the Greek “geo” (earth) and “kome” (hair or tendril), referring to its long, thin arms that radiate from a small central disc — a morphology that is both graceful and distinctive.

Morphological and Anatomical Features

The fossil displays exceptional preservation of the five slender, flexible arms characteristic of brittle stars. These arms are composed of articulated ossicles (small skeletal plates) that give the creature its name and enable the distinctive coiling or curling posture often seen in fossil specimens.

Key diagnostic features include:

• A small, round central disc with clearly defined plating.
• Five elongated, segmented arms, typically radiating symmetrically.
• Visible ambulacral grooves and internal arm structures preserved as natural impressions.
• Fine textural detail showing the plate arrangement and skeletal ornamentation.

These features make Geocoma libanotica a model organism for studying ancient echinoderm evolution. Brittle stars like this one are close relatives of modern starfish but belong to a distinct class within the echinoderms. Unlike starfish, brittle stars possess highly flexible arms used for locomotion rather than crawling tube feet.

Depositional Environment and Paleoecology

During the Cenomanian, the area now known as Lebanon was part of a tropical marine shelf environment along the edge of the Tethys Ocean. The Hakel Basin, where this specimen was found, was an oxygen-depleted lagoonal depression — a quiet, enclosed setting ideal for the preservation of fine fossils.

When brittle stars such as Geocoma libanotica died, their lightweight bodies settled intact onto the seabed. In most marine environments, their fragile skeletons would have been scattered by currents or scavengers. However, in Hakel’s unique anoxic conditions, the absence of scavengers and rapid sedimentation allowed even delicate echinoderms to fossilise in lifelike positions.

This form of preservation, where organisms are sealed quickly and completely, is characteristic of Konservat-Lagerstätten deposits, which capture even soft tissues and fine skeletal elements. It is this rare combination of geological and biological factors that makes Lebanese fossils so scientifically valuable and aesthetically striking.

Scientific and Collectible Importance

Geocoma libanotica is one of the most sought-after Cretaceous brittle stars due to its beauty, completeness, and historical significance. Fossils from the Sannine Formation are used by paleontologists to study the evolution of echinoderms and the ecological dynamics of Cretaceous marine life.

For collectors, this specimen represents both a piece of Earth’s geological history and a work of natural art. The fine limestone matrix highlights the contrast and definition of the fossil, while the symmetrical star-like form makes it a captivating display piece.

Each fossil is accompanied by a Certificate of Authenticity, verifying that it is a 100% genuine Cretaceous specimen from Hakel, Lebanon. This remarkable Geocoma libanotica fossil embodies over 95 million years of natural history, offering a timeless link to the marine world of the ancient Tethys Ocean — an extraordinary addition to any fossil, natural history, or scientific collection.