| Name:
Disparida (Order Uncertain); Triacrinus sp.
Age: Lower
Devonian (Seigenian/Emsian Stage)
Size mm (25.4
mm= 1 inch): Calyx: 15 mm - 80 mm, 45-205 mm with stems attached on a
285 by 145 mm matrix
Location:
Hunsruck Slate, Bundenbach Germany
|  Description:
Well-preserved example of an assemblage of EIGHT complete and partial
Disparid crinoids known as Triacrinus. 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.
These specimens show a distinct orientation due to a current that
flowed from left to right across the piece as pictured. The pyritization
serves as an artistic counterpoint to the rich black slate, making
for a truly striking display piece. Few examples of this quality
are ever seen; it is the only such piece I have been able to secure
in five years.
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