Skip to main content
Go to accessibility options

Peak season notice: Shipping for this category may take 14–21 business days after cleared payment. Thanks for your patience.

Description

Orthoceras Fossil Plaque
Geisonoceras sp.
Middle Devonian
Morocco

This monumental fossil plaque is composed of dense, black fossiliferous Marble and features an exceptional array of orthoceras specimens, highlighted by a remarkably large, fully exposed individual measuring nearly 60 inches in length at the center. The term orthoceras-meaning "straight horn"-refers to an extinct genus of straight-shelled cephalopods, closely related to modern squids and the chambered nautilus. The concentration of individuals within this slab suggests a mass mortality event, possibly the result of a sudden environmental shift during the Middle Devonian. Such groupings provide valuable paleontological evidence for the social, possibly colonial, behavior of Geisonoceras, a genus within the broader orthoceras grouping. Each fossil has been carefully polished to reveal the intricate internal chamber structure, which once allowed these marine animals to regulate buoyancy. At once scientific and sculptural, the plaque makes a powerful visual statement.
Overall Measurements: 68.00 x 35.00 x 3.00 inches (172.72 x 88.90 x 7.62 cm)

Provenance: Property of a Distinguished Southern California Collector


More Information: All items are offered "as is." While every effort has been made to accurately describe each lot, certain pieces—particularly fossils, minerals, and carvings—may exhibit minor imperfections, repairs, restorations, or natural wear consistent with age, excavation, or handling. Prospective buyers are encouraged to carefully review photographs and descriptions and to request additional condition information prior to bidding.


Estimate: $500 - up.

Condition Report*: Condition report available upon request.
*Heritage Auctions strives to provide as much information as possible but encourages in-person inspection by bidders. Statements regarding the condition of objects are only for general guidance and should not be relied upon as complete statements of fact, and do not constitute a representation, warranty or assumption of liability by Heritage. Some condition issues may not be noted in the condition report but are apparent in the provided photos which are considered part of the condition report. Please note that we do not de-frame lots estimated at $1,000 or less and may not be able to provide additional details for lots valued under $500. Heritage does not guarantee the condition of frames and shall not be liable for any damage/scratches to frames, glass/acrylic coverings, original boxes, display accessories, or art that has slipped in frames. All lots are sold "AS IS" under the Terms & Conditions of Auction.

Auction Info

Proxy Bidding Ends 
December
2nd Tuesday 10:50 am CT
Auction Dates
December
2nd Tuesday
Proxy Bidding Time Remaining 
9 Days 2h 11m 37s
Bids + Registered Phone Bidders: 5
Lot Tracking Activity: 29
Page Views: 232

Buyer's Premium per Lot:
25% of the successful bid (minimum $49) per lot.

This lot is in: 1 - Signature® Floor Session - Property of a Distinguished Southern California Collector (Live Floor, Live Phone, Mail, Fax, Internet, and Heritage Live):
(Lots 72001-72187) - 11:00 AM Central Time, Tuesday, December 2, 2025.
[Proxy bidding ends ten minutes prior to the session start time. Live Proxy bidding on Heritage Live now starts within 2 hours of when the auction opens for proxy bidding and continues through the live session.]

Show All Session Information

Show Auction Type Info

Exhibition Viewing Times, Title Page, Floor Session and License Information

Additional Location Info:
Heritage Auctions
2801 W. Airport Freeway
Dallas, TX 75261

Shipping, Taxes, Terms and Bidding
Charges to be determined based on Actual Shipping Costs incurred. Note: Additional invoice may follow original. Please contact us for more information. Sales Tax information

Important information concerning Sales Tax and Resale Certificates. Learn More

Terms and Conditions  |  Bidding Guidelines and Bid Increments |  Glossary of Terms
Current Bid:
$360
Track Item