Rhabdoderma
elegans
Crossopterygii,
Coelacanthiformwes, Rhabdodermatidae
Geological
Time: Pennsylvanian (~300 m.y.a.)
Size (25.4mm=1
inch): 35 mm across on a 49 mm by 38 mm nodule half
Fossil Site:
Pit 11, Francis Creek shale, Braidwood, Illinois
Code: CB75
Price: $650.00
- sold
 Description:
The Mazon Creek deposits of the region near Braidwood, Illinois
rival the other famous Lagerstatten of the Burgess Shale, Solnhofen,
and Liaoning for the variety of detailed life preserved. Many exquisitely
preserved specimens are found in the ironstone nodules that make
up the deposits. The majority of collecting areas are the spoil
heaps of abandoned coal mines, the most famous of which is Peabody
Coal Pit 11. Pit 11 now serves as a cooling pond for the Braidwood
nuclear power plant, but with over 100 other localities, specimens
still come to light. This fish has a rather cosmopolitan distribution,
and is found in Carboniferous coal bed deposits of North America
and Europe.
This
fine example displays the diagnostic double dorsal, but the “tassel”
of the central portion of the caudal is not preserved. Notice the
large yolk sac. This one did no survive long. The three dark structures
seen may be pyrite nodules. Some prefer to separate this one from
Rhabdoderma elegans, and use the name Rhabdoderma exiguum. Whatever
you call it, this is a remarkably well-preserved example.
|
|
