Description
Genuine Micraster cf. leskei Echinoid Fossil from Eastbourne, East Sussex
This genuine fossil is a carefully selected specimen of Micraster cf. leskei, an extinct irregular echinoid, or heart urchin, collected from the Chalk Group near Eastbourne, East Sussex, United Kingdom. The fossil dates to the Turonian Stage of the Upper Cretaceous, approximately 93.9 to 89.8 million years ago, when southern Britain lay beneath a vast warm tropical sea rich in marine life.
The abbreviation “cf.” (confer) indicates that the specimen closely resembles Micraster leskei and is assigned to that species with a high degree of confidence, while acknowledging slight uncertainty due to preservation or incomplete diagnostic features. This is a common and accepted practice in palaeontology when identifying fossil specimens.
The photographs show the exact fossil you will receive. Please refer to the images for the specimen’s full dimensions, shape, preservation, colour and condition. As every fossil has undergone millions of years of natural geological processes, no two specimens are ever identical.
Fossil Species and Scientific Classification
Micraster cf. leskei belongs to the Phylum Echinodermata, Class Echinoidea, Order Spatangoida, Family Micrasteridae, and Genus Micraster. Members of this genus are among the most famous fossil echinoids from the British Chalk and are internationally recognised as important index fossils used in Upper Cretaceous stratigraphy.
The genus Micraster is characterised by its distinctive heart-shaped test, pronounced bilateral symmetry and highly specialised anatomy adapted for life beneath the seabed. The species Micraster leskei was originally described by Goldfuss in 1829 and represents one of the earlier evolutionary forms within the Micraster lineage that eventually gave rise to later species such as Micraster coranguinum.
Distinctive Morphological Features
Unlike regular sea urchins that grazed across the sea floor, Micraster evolved for a burrowing lifestyle within soft carbonate sediment. Its test is typically heart-shaped to oval with a gently domonate upper surface and a flattened underside.
Characteristic features include a shallow anterior sulcus, well-developed petaloid ambulacra on the upper surface, paired pore zones for the tube feet and a posteriorly positioned periproct. The mouth is situated towards the front of the underside, enabling the animal to feed efficiently while moving through soft sediment.
Fine granulation, plate sutures and ambulacral patterns are often preserved in well-preserved specimens. The exact features visible on this fossil depend upon its natural preservation and can be examined in the accompanying photographs.
Chalk Group Geology of Eastbourne
Eastbourne is internationally renowned for its spectacular Upper Cretaceous Chalk cliffs, including the famous exposures extending towards Beachy Head and the Seven Sisters. These rocks form part of the Chalk Group, deposited during a period when southern Britain was submerged beneath the extensive north-west European Chalk Sea.
The chalk consists primarily of microscopic calcareous plates from coccolithophores that accumulated over millions of years on the seabed. Gradual burial and compaction transformed these sediments into the brilliant white limestone that now forms the iconic cliffs of southern England.
Within the succession are marl seams, hardgrounds and flint horizons that provide important marker beds for geological correlation. These coastal exposures have been studied for over two centuries and remain among the finest Upper Cretaceous sections in Europe.
Biostratigraphic Importance
Species of Micraster are among the most valuable macrofossils used for dating and correlating Upper Cretaceous chalk deposits. Progressive evolutionary changes in their shape and anatomical features allow palaeontologists to distinguish successive horizons within the Chalk Group with remarkable precision.
Micraster cf. leskei represents one of the earlier members of this evolutionary lineage during the Turonian, preceding the better-known Coniacian and Santonian species such as Micraster coranguinum. Fossils of this type provide important evidence for understanding the evolution of irregular echinoids and the changing environments of the Late Cretaceous seas.
Ancient Marine Environment
During the Turonian, East Sussex lay beneath a warm, relatively deep marine sea with exceptionally clear water and very little input of sand or mud from nearby land. This environment encouraged the accumulation of fine carbonate sediment and supported a rich ecosystem of marine organisms.
The Chalk Sea was inhabited by echinoids, ammonites, belemnites, brachiopods, bivalves, bryozoans, crinoids, sponges, fish, sharks and marine reptiles. Micraster cf. leskei lived partially buried within the soft seabed, using its specialised tube feet for movement, respiration and feeding on organic-rich sediment.
Its streamlined body shape enabled efficient burrowing, while the covering of fine movable spines helped transport sediment around the body and assisted locomotion beneath the sea floor. This infaunal lifestyle offered protection from predators and changing environmental conditions.
A Genuine British Fossil for Collectors
This authentic Micraster cf. leskei fossil is an excellent addition to any fossil collection, geological display, educational resource or natural history cabinet. Specimens from the classic Chalk Group of Eastbourne are highly sought after by collectors because of their scientific importance and their connection with one of Britain’s most celebrated geological landscapes.
The fossil is a genuine specimen and includes a generic Certificate of Authenticity with a lifetime guarantee. The photographs show the exact specimen you will receive, allowing you to purchase with complete confidence. Please refer to the listing images for the full size and overall condition of this individual fossil.
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