Urasterella verruculosa
Furcaster zitelli
Phylum Echinodermata, Subphylum Asterozoa, Class Ophiuroidea
Geological Time: Lower Devonian, Seigenian/Emsian Stage
Size (25.4 mm = 1 inch): Urasterella fossil has a 80 mm armspan (maximum), Furcaster has 85 mm armspan (maximum), on a 165 by 230 mm matrix
Fossil Site: Hunsruck Slate, Bundenbach Germany
Code: GF058
Price: $825.00
 Description:
Well-preserved example of a pair of Ophiuroids (brittlestars) known
as Urasterella verrucucolsa and Furcaster zitelli. Both the family
Asterozoa (True Starfish) and Ophiuroidea (Brittlestars) are known
by the common term “starfish”. 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. This one is quite well-preserved. The
species name for the one specimen refers to its verruculose exoskeleton,
a word that means covered with wart-like prominences. The other
has a more classic brittlestar appearance. It is quite uncommon
to have two specimens of such diverse morphology on one plaque,
making this a most unique example to add to any collection. |
