Description
Acrosalenia hemicidaroides Echinoid Fossil with Spines – Bajocian Stage, Middle Jurassic, Neufchâteau, France
This exceptionally rare fossil specimen features a beautifully preserved Acrosalenia hemicidaroides echinoid, complete with fossilised spines, from the Bajocian stage of the Middle Jurassic, approximately 170 to 168 million years ago. It was discovered in the renowned marine fossil deposits of Neufchâteau, northeastern France.
Fossil Type & Species:
- Type: Invertebrate Fossil (Echinoid/Sea Urchin + Detached Spines)
- Species: Acrosalenia hemicidaroides
- Phylum: Echinodermata
- Class: Echinoidea
- Order: Cidaroida
- Family: Hemicidaridae
- Described by: d’Orbigny, 1850 (species known since the mid-19th century)
Geological & Stratigraphic Details:
- Location: Neufchâteau, Vosges, France
- Formation: Bajocian marine limestone/marl layers
- Geological Stage: Bajocian, Middle Jurassic
- Age: ~170–168 million years ago
- Depositional Environment: Shallow marine carbonate platform, ideal for echinoderm preservation due to low-energy sedimentation and early calcite mineralisation
- Biozone: Bajocian ammonite biozones (exact echinoid zonation not formally assigned)
Morphology & Features: This fossil displays key traits of Acrosalenia hemicidaroides:
- Spherical to sub-hemispherical test (shell) with intricate tubercle patterns
- Thick, robust primary spines, often found detached and fossilised alongside the test
- Ambulacral plating in orderly radial arrangement with fine granulation
- Distinct oral and aboral surfaces, sometimes visible in partially exposed or prepared examples
- Colour ranges from pale grey to light brown due to local matrix mineralisation
Notable: This species is a classic example of Jurassic cidaroid echinoids and is rarely found with spines preserved in association. The presence of spines makes this a scientifically significant and highly aesthetic specimen, ideal for both collectors and educators.
Specimen Details:
- Origin: Neufchâteau, France
- Species: Acrosalenia hemicidaroides
- Fossil Type: Echinoid (Sea Urchin) Test and Spines
- Geological Stage: Bajocian, Middle Jurassic
- Size Reference: Scale rule square = 1cm (see listing photos for accurate sizing)
- Note: The specimen pictured is the exact item you will receive
Authenticity & Quality: All our fossils are guaranteed genuine and carefully selected. This piece includes a Certificate of Authenticity and has not been restored or enhanced.
Why Choose This Fossil? An ideal specimen for:
- Serious fossil collectors and echinoderm enthusiasts
- Museum or university-level palaeontology displays
- Decorative fossil showcases
- Education in marine palaeobiology and Jurassic ecosystems
Shipping & Packaging: All items are professionally packed with eco-conscious materials and shipped via tracked services for safe delivery.
Add a stunning piece of Jurassic marine life to your collection with this rare Acrosalenia hemicidaroides echinoid fossil complete with spines from Neufchâteau, France.
All of our Fossils are 100% Genuine Specimens & come with a Certificate of Authenticity.
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