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Coelacanth in copper shale

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Before preparation: the rock is crumbly and flakes off in thin layers,
the fossil substance fragile and "baked" with harder parts of the rock

Before preparation: the rock is crumbly and flakes off
in thin layers, the fossil substance fragile and "baked"
with harder parts of the rock

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The fossil was secured and the preparation using
fine air abrasives has begun

The fossil was secured and the
preparation using
fine air abrasives has begun

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The finished slab after the preparation work

The finished slab after the preparation work

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Fish fossils from the copper shale of the Mansfeld region are well known in Germany. Palaeoniscus freieslebeni in particular is relatively common, although well-preserved, complete specimens can only be found with patience and luck. Remains of coelacanths are rare, so it is worth to prepare incomplete parts, too.

This specimen already showed potential for further preparation in its “as-found-condition”, but also some difficulties: The copper slate is badly weathered, crumbling and flaking off in thin layers. The plate had to be secured first of all so that it would not break during processing. The fossil substance is also extremely fragile and mostly lies between the weathered layers, so that it had to be secured with sufficient adhesive too. Other parts of the rock, however, are relatively hard and “baked” with the fossil. The preparation was therefore carried out extremely carefully using fine air abrasives under the binocular. The fine details of the fragile fossil were preserved and exposed in this way.

Fossil: Coelacanthus granulatus

Locality: Mansfelder Mulde (Germany)

Formation: Permian, Zechstein 1

Length of the plate: 16 cm (6.3 inch)

Collection: Renate Meincke

Work required: 4 hours