Description:

North Africa, Morocco, Devonian Period, ca. 419.2 to 358.9 million years ago. This large, circular fossil slab is polished to reveal dramatic Orthoceras and ammonite specimens embedded within a deep black stone matrix. The verso is sealed for stability and durability. A decorative and functional piece showcasing millions of years of natural history which can be mounted onto custom metal legs for use as a unique table, or placed directly atop an existing surface to serve as a monumental coaster or display tray. Perfect for interiors that celebrate organic forms and geological wonders. Size: 24" Diameter x 0.75" W (61 cm x 1.9 cm)

Prehistoric 'straight' cephalopods include straight ammonoids called orthoceras. Cephalopod evolution began during the Late Cambrian Period. Some of these creatures evolved into semi-coiled forms, eventually giving rise to coiled cephalopods like ammonites and nautili. Straight cephalopods were among the most advanced invertebrates of their time, with eyes, jaws, and a sophisticated nervous system. These creatures were predators that swam freely using a jet propulsion system by squirting water from their bodies. They had tentacles and ink sacs, much like present-day squid. Except for belemnites, cephalopods had external shells with hollow internal chambers separated by walls called septa. A tube called the siphuncle connected the body with the chambers allowing the animal to fill them with water or air, changing its buoyancy in order to rise or drop in the ocean. Only the last and largest chamber was occupied by the living animal!

Provenance: private Colorado, USA collection

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Item # 196493

  • Condition: Professionally cut and polished on one planar face. Some uneven edges and scratches.

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Shipping

Auction House will ship, at Buyer's expense

May 15, 2026 9:00 AM MDT
Louisville, CO, US

Artemis Fine Arts

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Bid Increments
From: To: Increments:
$0 $299 $25
$300 $999 $50
$1,000 $1,999 $100
$2,000 $4,999 $250
$5,000 $9,999 $500
$10,000 $19,999 $1,000
$20,000 $49,999 $2,500
$50,000 $99,999 $5,000
$100,000 $199,999 $10,000
$200,000 + $20,000