#Jurassic echinoidea fossil

[uk-fossils]

Pseudodiadema depressum Regular Echinoid Fossil, Oxfordian Stage, Jurassic France | Authentic Specimen + COA

Pseudodiadema depressum Regular Echinoid Fossil – Oxfordian Stage, Late Jurassic, Cricqueboeuf, Normandy, France

This fine fossil specimen represents Pseudodiadema depressum, a regular echinoid (sea urchin) from the Oxfordian stage of the Late Jurassic, approximately 159 to 154 million years ago. It was recovered from the fossil-rich marine limestone beds of Cricqueboeuf, a renowned site in Normandy, northern France.

Fossil Type & Species:

Type: Invertebrate Fossil (Regular Echinoid / Sea Urchin)

Species: Pseudodiadema depressum

Phylum: Echinodermata

Class: Echinoidea

Order: Cidaroida

Superfamily: Pseudodiadematoidea

Family: Pseudodiadematidae

Described by: Cotteau, 1863

Geological & Stratigraphic Details:

Location: Cricqueboeuf, Calvados, Normandy, France

Formation: Oxfordian marine limestones

Geological Stage: Oxfordian (Upper Jurassic)

Age: ~159–154 million years ago

Biozone: Perisphinctes ammonite zone (regional correlation)

Depositional Environment: Shallow marine carbonate platform with calm, warm seas; ideal for the preservation of delicate echinoid shells in fine-grained limestones

Morphology & Features: This Pseudodiadema depressum specimen features:

Sub-hemispherical, symmetrical test with clear ambital outline

Densely arranged primary and secondary tubercles forming a detailed lattice across the shell

Well-developed ambulacral and interambulacral zones, sometimes showing fine pore structures

No spines attached, but tubercle structure suggests strong spine-bearing capability

Subtle colour variations from beige to pale brown, depending on matrix contact

Notable: Pseudodiadema depressum is a classic species of Jurassic echinoid used in palaeoenvironmental and biostratigraphic studies. Its compact test and distinctive tubercle patterning make it both scientifically important and visually appealing.

Specimen Details:

Origin: Cricqueboeuf, Normandy, France

Species: Pseudodiadema depressum

Fossil Type: Echinoid Shell (Regular Sea Urchin)

Geological Stage: Oxfordian, Late Jurassic

Size Reference: Scale rule square = 1cm (please refer to the listing photo for full size)

Note: You will receive the exact specimen shown in the photographs

Authenticity & Quality: All our fossils are genuine and professionally selected. This specimen includes a Certificate of Authenticity. No restorations or artificial enhancements are applied.

Why Choose This Fossil? Perfect for:

Fossil and echinoderm collectors

Academic and educational purposes

Natural history displays

Unique gifts with palaeontological value

Shipping & Packaging: Eco-conscious packaging and tracked global shipping ensure secure and swift delivery. Each fossil is packed with care to preserve detail and structure.

Own a finely preserved sea urchin from the Jurassic oceans of France with this authentic Pseudodiadema depressum echinoid fossil.

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

[justonemorerock]

New Sand Dollars (Echinoidea) have just gone live on both stores! Sand Dollar Fossils (Echinoidea) are fossilised sea urchins from the Jurassic period and are around approximately 145 - 200 million years old. Keywords: Transformation & Growth. https://www.instagram.com/p/CVhSST6vsnJ/?utm_medium=tumblr

[fenglichina-blog]

Chalk Industrial Grinding Machine

Chalk is a soft, white, porous sedimentary carbonate rock, a form of limestone composed of the mineral calcite. Calcite is calcium carbonate or CaCO3. It forms under reasonably deep marine conditions from the gradual accumulation of minute calcite shells (coccoliths) shed from micro-organisms called coccolithophores. Flint (a type of chert unique to chalk) is very common as bands parallel to the bedding or as nodules embedded in chalk. It is probably derived from sponge spicules or other siliceous organisms as water is expelled upwards during compaction. Flint is often deposited around larger fossils such as Echinoidea which may be silicified (i.e. replaced molecule by molecule by flint).

Chalk as seen in Cretaceous deposits of Western Europe is unusual among sedimentary limestones in the thickness of the beds. Most cliffs of chalk have very few obvious bedding planes unlike most thick sequences of limestone such as the Carboniferous Limestone or the Jurassic oolitic limestones. This presumably indicates very stable conditions over tens of millions of years.

Chalk Industrial Grinding Machine can be used to grind barite, calcite, kalium, steatite, marble, glass, feldspar, etc. superfine grinding mill is widely used in the metallurgy, building, chemical industry, and mining field..

Chalk Industrial Grinding Machine Suppliers

Depending on the producing and researching experiences of decades, Fujian Fengli Machinery has become a major ultrafine powder processing equipment manufacturer and export base.

TEL: +86-597-2285225 FAX: +86-597-2285185 Office Add: Y68# Longzhou Industrial Park Industrial West Road Xinluo District Longyan 364000 Fujian China Postcode: 364000 Email: sales2@fengli-china.com

You may also like read more about Chalk Industrial Grinding Machine at http://www.fengli-china.com.

[uk-fossils]

Acrosalenia hemicidaroides Echinoid Fossil + Spines, Bajocian Stage, Jurassic France | Rare Authentic Specimen + COA

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.