#Micraster echinoderm fossil

[uk-fossils]

Micraster cortestudinarium Fossil Echinoid Sea Urchin, Upper Chalk, Cretaceous Kent UK | Authentic Specimen + COA

Micraster cortestudinarium Fossil Echinoid – Upper Chalk, Late Cretaceous, Kent, United Kingdom

This beautifully preserved fossil sea urchin is a specimen of Micraster cortestudinarium, one of the most iconic echinoids of the Late Cretaceous. Collected from the Upper Chalk deposits of Kent, southern England, it dates to the Turonian–Coniacian stages of the Late Cretaceous, approximately 90 to 86 million years ago.

Fossil Type & Classification:

Type: Invertebrate Fossil (Regular Echinoid / Sea Urchin)

Species: Micraster cortestudinarium

Phylum: Echinodermata

Class: Echinoidea

Order: Spatangoida

Superfamily: Spatangoidea

Family: Holasteridae

Genus: Micraster

Described by: Goldfuss, 1826 (genus authority)

Geological & Stratigraphic Details:

Location: Kent, United Kingdom

Formation: Upper Chalk Formation

Geological Stage: Turonian–Coniacian, Late Cretaceous

Age: ~90–86 million years ago

Biozone: Micraster cortestudinarium Biozone – named after this species and commonly used in European chalk stratigraphy

Depositional Environment: Warm, shallow marine shelf with low sedimentation rates and high calcium carbonate content, perfect for preserving echinoderm fossils in fine chalk matrix

Morphology & Features: This Micraster cortestudinarium specimen exhibits:

Heart-shaped, domed test with symmetrical bilateral profile

Well-defined ambulacra and petaloid pattern on the upper surface

Distinct anterior groove and central apical system

Fine surface granulation and pore rows visible depending on preservation

Preserved in light grey to creamy white chalk matrix, typical of Upper Cretaceous marine deposits

Notable: Micraster is one of the most important and widely distributed echinoid genera of the Upper Cretaceous. The species M. cortestudinarium serves as a key biostratigraphic marker for the British and European chalk and is frequently used in educational and museum contexts for illustrating Cretaceous sea life. Its abundance and diversity reflect significant evolutionary adaptations during the Cretaceous marine radiation.

Specimen Details:

Origin: Kent, UK

Species: Micraster cortestudinarium

Fossil Type: Regular Echinoid (Sea Urchin Test)

Geological Stage: Turonian–Coniacian, Late Cretaceous

Formation: Upper Chalk

Size Reference: Scale cube = 1cm (please refer to listing photos for exact dimensions)

Note: The exact fossil shown in the listing photo is the one you will receive

Authenticity & Quality: This fossil is 100% genuine, professionally sourced and naturally preserved. It includes a Certificate of Authenticity and has not been artificially enhanced.

Why Choose This Fossil? Excellent for:

Echinoid fossil collectors

Educational fossil displays and teaching

British Cretaceous marine collections

Natural history gifts and décor

Shipping & Packaging: Fossils are packed with eco-conscious materials and shipped with full tracking. Every item is handled carefully to ensure it arrives safely.

Bring home a genuine piece of Britain’s ancient sea life with this authentic Micraster cortestudinarium echinoid fossil from the Upper Chalk of Kent.

All of our Fossils are 100% Genuine Specimens & come with a Certificate of Authenticity.

[untreacherous]

The Sedgwick Museum is heavenly, and totally satisfying my Echinoid obsession right now. #Cambridge #museum #sedgwickmuseum #fossils #paleontology #micraster #echinoderm (why is there no emoji for these?) (at Sedgwick Museum of Earth Sciences)