Order Phacopida, Family Phacopidae
Time: Lower Devonian, Seigenian/Emsian Stage
is 82 mm long by 37 mm wide on a 140 mm by 145 mm matrix
Site: Hunsrück Slate, Bundenbach Germany
This trilobite is known as Chotedops ferdinadi. Its pustulose glabella
is reminiscent of that of the more commonly seen genus Phacops.
Indeed, it is a member of the same family; Phacopidae. This one
is preserved in dorsolateral aspect, and shows facets to the eye.
The Hunsruck slate is famous for its fossils, many of which have
pyritization present. Rapid burial and pyritization was what led
to the many wonderful examples of early Devonian life from the region.
The chemistry of the silt was such that low organic content and
high levels of iron and sulfur allowed the pyrite to diffuse into
the tissues rather than be deposited in the sediment. The mudstones
were metamorphosed into slate during the Carboniferous. The slate
was quarried for roofing tiles, and the quarrymen would save the
fossils for later sale. Now that the quarries are no longer open,
future supplies of these wonderfully-preserved benthic organisms
will only come from existing collections.
trilobite pictures to enlarge