Ammonite Apthychus - Fossilised shell (No reserve price)

Beautifully preserved pair of Aptychi from the Lower Toarcium (Lias) of Bad Böll near Holzmaden. The layers of the Posidonienschiefer exposed there are about 180 million years old. Aptychi are bivalved, shell-like fossils made of calcite that served as the lower jaw of extinct ammonites. They consist of two mirror-image, symmetrically arranged calcite plates. Since calcite is more stable during fossilization than the rest of the ammonite shell, which consisted of aragonite, Aptychi are occasionally found in the rock as isolated fossils. In this fortunate find, when splitting the stone slab, this complete Aptychus was revealed as both a positive and a negative (imprint), with preservation of all the finest details. This is an approximately 7 cm high and 4.5 cm wide specimen of the Aptychus genus Cornaptychus ovatus, and it belonged to an ammonite of the genus Harpoceras. As a bonus, an additional rock slab is included, with a small single half of an Aptychus about 2 cm in size. This could be a different species. Shipping is done with DHL and tracking.

估價:$1.12

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