Peltoceratoides sp. & Cosmoceras sp. Ammonites
Geological Time: Jurassic, Callovian Stage
Size (25.4 mm = 1 inch): Peltoceratoides: 54 mm diameter Cosmoceras: 45 mm diameter matrix: 85 mm by 75 mm
Fossil Site: Ulyanovsk, Russia
Code: RA356
Price: $135.00 - sold
 Description:
A magnificent example of the ammonite Peltoceratoides sp. in association
with a Cosmoceras of the Callovian Stage (161 m.y.a) deposits of Russia.
The taxon derives its name from its relationship to Peltoceras. Ammonites
of this degree of preservation are difficult to come across singly,
much less as a pair. The high degree of preservation of the natural
mother-of-pearl shell makes it appear to be preserved as fire opal.
This is a consequence of light passing through the various layers
of aragonite and conchiolin deposited by the ammonite in life. This
is an uncommon genus, and I only obtain a small handful annually,
of which this is a fine example. |
