Name: Porifera, Class Hexactinellida (glass sponge fossil)
Age: Lower Devonian, Seigenian/Emsian Stage
Size: (25.4mm=1 inch): 192 mm long, 38 mm across on a 180 by 282 mm matrix.
Location: Hunsruck Slate, Bundenbach Germany
Code: B008
Price: $350.00 - Sold
 Description:
Well-preserved example of a member of the Hexactinellida (Glass Sponges).
Glass Sponges are so named because their spicules are made of silica.
These spicules are often cemented together into a roughly cylindrical
skeleton. This one strongly resembles Euplectella, the Venus' Flower
Basket. This recent example is often found with a pair of shrimp inside
which form a symbiotic relationship with the sponge: the sponge provides
shelter, and gets to feed on the waste products of the shrimp. Such
examples are sometimes given as wedding presents in Japan and the
Philippines as symbols of wedded bliss. 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 pyritization of this one is quite extensive, making
for an esthetic display piece. 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. Complete
specimens such as this are rarely offered, making this a must-have
for any collector of Bundenbach material. |
