615mm Knightia Eoceana Mortality Slab - Eocene Epoch, Green River Formation, Wyoming, USA

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An exceedingly rare large-scale fossil slab from the Green River Formation, presenting a shoal of four beautifully preserved Knightia Eoceana.

Measuring 615mm long by 410mm wide (24" x 16") and an impressive 25mm thick, this is a substantial museum-grade specimen with real presence, far exceeding the size of typical Green River fish specimens.The composition is especially appealing, with four fish naturally arranged in a shoal formation.

Each fish is well-defined and intact, with clear anatomical detail throughout including fins, scales, and fine skeletal detail, contrasting beautifully against the natural limestone’s attractive tone.

Green River Formation fossils date to the Eocene epoch, approximately 50 million years ago, and are renowned for their exceptional preservation. Large, multi-fish slabs of this scale and condition are becoming increasingly difficult to source particularly examples that remain structurally intact and visually balanced.

The matrix itself is solid and stable, with no visible cracks, repairs, or compositing. Slabs of this size are commonly fractured and later restored due to stresses during excavation, making this an increasingly uncommon and desirable characteristic. The proportions and thickness give this slab a strong, stable feel, making it particularly well-suited for long-term display.

A true statement piece suited to a serious collection or as a centrepiece display in a home or gallery. The overall presentation leans as much toward wall-mounted art as it does a traditional fossil specimen, giving it broad appeal across both collectors and interior display settings.

Specimen Details

 Species: Knightia eocaena

 Formation: Green River Formation

Location: Wyoming, USA

Geological Age: Eocene Epoch, ~50 million years

Composition: Natural limestone matrix containing four fossil fish in shoaling formation  

 Dimensions (Matrix): 615 mm (L) x 410 mm (W) x 25 mm (D)

 Fish Sizes (approx):
130 mm, 125 mm, 110 mm, 112 mm  

Condition: Well-preserved and structurally solid slab. No visible cracks, repairs, or compositing within the natural matrix. All four specimens display complete anatomy, including fins, scales, and fine skeletal detail.

 Preparation:  Carefully prepared to expose fossil detail while retaining the natural character of the surrounding matrix.

Provenance: Genuine fossil specimen from the Green River Formation, one of the world’s most renowned fossil sites for exceptional preservation. Exported legally from the United States to the UK by ourselves.

 Notes: Large multi-fish slabs of this scale and condition are increasingly scarce, particularly examples that remain intact without restoration.

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