Description
Rare Genuine Metopaster uncatus Fossil Starfish
This carefully chosen fossil is a genuine specimen of Metopaster uncatus, an extinct sea star from the Upper Cretaceous Chalk Group at Dumpton Gap, Kent, United Kingdom. Catalogued as Cenomanian in age, it represents a highly collectable example of the marine echinoderms that inhabited the ancient Chalk Sea during the Late Cretaceous Period.
Starfish fossils are considerably rarer than many shells, echinoids and ammonites because the body of a sea star consists of numerous separate calcite plates held together by soft connective tissues. After death, these tissues decayed rapidly, allowing the skeleton to break apart. Specimens preserving recognisable starfish anatomy or associated skeletal plates are therefore especially desirable to collectors of British fossils and prehistoric marine life.
The photographs show the actual specimen you will receive. Please examine them carefully for full sizing, scale, shape, visible anatomical features, colour, natural chalk matrix and preservation. Any incomplete margins, separated plates, mineral staining, surface wear or natural fractures form part of the fossil’s genuine geological history.
Species and Scientific Classification
Metopaster uncatus belongs to the phylum Echinodermata, subphylum Asterozoa, class Asteroidea, order Valvatida and family Goniasteridae. This family contains sea stars noted for their firm, well-armoured bodies and conspicuous marginal plates.
The species was originally described by the British naturalist and palaeontologist Edward Forbes in 1848 as Goniaster uncatus. The genus Metopaster was later established by the British zoologist Walter Percy Sladen in 1893, resulting in the accepted combination Metopaster uncatus (Forbes, 1848).
The genus is known from European marine deposits extending from the Late Cretaceous into the early Palaeogene. Its robust construction made it more resistant to disintegration than many lightly built sea stars, although complete articulated specimens remain uncommon.
Distinctive Metopaster Morphology
Metopaster uncatus possessed a compact, flattened body with five arms arranged around a central disc. Its arms were relatively short and broad compared with the long, tapering arms seen in many modern starfish. This produced a pentagonal or cushion-like overall outline.
One of the most recognisable features of Metopaster is the strongly developed marginal frame. Rows of enlarged calcitic plates, known as superomarginal and inferomarginal ossicles, formed the outer edge of the body and arms. These robust plates protected the softer internal tissues and helped maintain the animal’s shape.
Individual marginal ossicles may appear block-like, wedge-shaped or curved according to their original position. Plates from the tips and corners of the arms can have particularly distinctive outlines. The upper surface was formed from smaller abactinal plates, while the underside carried ambulacral grooves containing the tube feet.
The species name “uncatus” refers to hooked or curved characteristics associated with its skeletal form. Depending on preservation, this specimen may display marginal ossicles, portions of an arm, sections of the central disc, surface granulation, plate boundaries or an impression within the surrounding matrix.
Sea Star Movement and Feeding
Like living starfish, Metopaster uncatus moved using rows of flexible tube feet extending from grooves on its underside. These tube feet formed part of the water vascular system, a hydraulic arrangement unique to echinoderms.
Seawater entered the system through a porous plate called the madreporite. Internal canals distributed fluid throughout the body, allowing individual tube feet to extend, attach to the substrate and contract. Coordinated movement of hundreds of tube feet enabled the animal to travel slowly across the Cretaceous seabed.
Members of the Goniasteridae are generally interpreted as benthic feeders. Metopaster may have consumed small molluscs, microorganisms, organic detritus and other slow-moving or attached animals. Its mouth was positioned centrally on the underside, while the upper surface carried the anus and madreporite.
The heavily plated body provided protection while the sea star moved across soft carbonate sediment searching for food.
Upper Cretaceous Chalk Group Geology
The Chalk Group is a major sequence of Upper Cretaceous marine limestone extending across southern and eastern England. It was deposited when exceptionally high sea levels submerged much of Britain beneath a warm epicontinental sea.
Chalk is composed predominantly of microscopic calcium-carbonate plates called coccoliths. These were produced by immense populations of single-celled marine algae known as coccolithophores. When the organisms died, their skeletal plates descended through the water and accumulated as pale carbonate ooze on the seabed.
Shell fragments, echinoderm ossicles, sponge spicules and the remains of other marine animals became mixed with this sediment. Continued burial compacted the carbonate mud, while mineral cementation gradually transformed it into chalk limestone.
The Chalk Group can also contain marl seams, harder limestone beds, fossil-rich horizons and flint nodules. Flint formed when dissolved silica, much of it derived from sponge skeletons and other microorganisms, migrated through the sediment and became concentrated within particular layers.
Dumpton Gap Fossil Locality in Kent
Dumpton Gap lies on the Thanet coast between Broadstairs and Ramsgate in Kent. The coastal cliffs form part of the extensive Upper Cretaceous Chalk landscape of south-east England and provide an important natural exposure of marine rocks deposited within the ancient Chalk Sea.
Weathering and coastal erosion gradually release fossils from the cliffs and fallen chalk. Typical finds from the wider Kent Chalk include echinoids, sponges, brachiopods, bivalves, oysters, bryozoans, belemnite remains, fish material and isolated echinoderm plates.
Starfish fossils are among the less frequently encountered remains. Their articulated skeletons usually separated soon after death, meaning that individual ossicles are much more common than complete body fossils. A recognisable Metopaster uncatus specimen from this historic Chalk coastline is consequently an appealing addition to a specialist British fossil collection.
Ancient Chalk Sea Depositional Environment
The sea covering southern Britain was warm, open and generally distant from major sources of sand and coarse terrestrial sediment. This allowed extremely fine calcareous mud to settle slowly through the water.
The seabed supported a diverse ecosystem. Sponges filtered seawater through complex canal systems, while brachiopods, oysters and bivalves occupied suitable surfaces. Echinoids grazed across the sediment or burrowed beneath it, and crinoids raised feathered feeding arms into passing currents.
Fish, sharks, ammonites and marine reptiles occupied the water column above. Bryozoans formed delicate colonies, while starfish such as Metopaster uncatus moved across the seabed in search of prey and organic material.
The occurrence of a benthic sea star indicates a well-established bottom-dwelling community supported by the biological productivity of the overlying water.
Fossilisation and Rare Preservation
A sea star skeleton is constructed from hundreds of calcite ossicles rather than a single solid shell. These plates are joined by muscles and connective tissues during life. Once the animal died, decomposition weakened the connections and currents or scavengers could rapidly scatter the skeleton.
Successful preservation required the body to become covered by sediment before extensive disarticulation occurred. Fine chalk mud could surround the animal, filling spaces between plates and protecting the remains from further disturbance.
Even after burial, compaction and mineral movement could separate, dissolve or distort individual ossicles. Some fossils survive as articulated skeletal material, while others are preserved as natural moulds, impressions or groups of associated plates.
The unusually robust marginal frame of Metopaster increased its preservation potential compared with more delicate starfish. Nevertheless, identifiable specimens remain scarce compared with common Chalk echinoids and brachiopods, supporting the rare and collectable nature of this fossil.
Authentic British Starfish Fossil with Certificate
This genuine Metopaster uncatus fossil is ideal for collectors of rare British fossils, fossil starfish, Chalk Group specimens, Cretaceous echinoderms and Kent palaeontology. Its distinctive armoured morphology and Dumpton Gap provenance give it strong natural-history, educational and display appeal.
The specimen includes a generic Certificate of Authenticity card carrying a lifetime guarantee of authenticity. It has been individually selected for its natural appearance, rarity, geological interest and collectable character. The photographs show the exact specimen you will receive, and full sizing can be seen in the photographs.
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