Bandringa
rayi
Order Selachii,
Suborder Ctenacanthoidea, Family Bandringidae
Geological
Time: Pennsylvanian (~300 m.y.a.)
Size (25.4
mm = 1 inch): Fossil is 45 mm long (curve measure), Matrix: 40 mm by
40 mm nodule pair
Fossil Site:
Pit 11, Mazon Creek, Braidwood, Illinois
Fossil Code:
RCF01
Price: 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 one is of the bizarre shark
with a long rostrum known as Bandringa rayi. This particular
one is seen in dorsal aspect with the eyes quite evident. The
nodule split in such a way that the rostrum is preserved
in only one side. It is difficult to see unless the light catches
it
just right. I have included a negative photograph (to the right)
to point it out more clearly. Until recently, there were thought
to be
two
species: B. rayi and B herdinae, with the latter found in freshwater
deposits in Ohio and Pennsylavania, while the Mazon Creek species
was preserved in brackish and saltwater deposits. A publication
earlier this year presents the conclusion that there is in fact
only one species, and that they hatched in a marine environment
and moved into freshwater to grow and mature. Whatever the case
Bandringa rayi from Mazon Creek is a very scarce animal with
only some 50 examples known at present. Discovered
by collector Ray Bandringa in 1967, this is another shining example
of the
value of amateur paleontologists to the scientific community.
References:
Fieldiana Geology, Vol 12 No 10 Mar 24, 1969, pp157-169
Journal
of Vertebrate Paleontology, Vol 34 No 1, 2014.
|
|