Glochiceras (Coryceras) microdomum
Class Cephalopoda, Subclass Ammonidea, Order Ammonitida, Family Haploceratidae
Geological Time: Upper Jurassic
Size (25.4 mm = 1 inch): Ammonite is 28 mm across on a 65 mm by 50 mm matrix
Fossil Site: Malm Alpha 3, Gratenberg, Germany
Fossil Code: RS138
Price: $95.00 - sold
 Description:
A magnificent example of the ammonite Glochiceras. of the Jurassic
of Germany. Ammonites are often sexually dimorphic, displaying
both a macroconch (large shell) and microconch (small shell).
Since examples of the macroconch have been found with eggs, they
are presumed to be the females. The microconch in addition to
being somewhat smaller, has more ornate knobs and spines, as
well as often displaying a structure known as the lappet at the
front of the living chamber. The lappet is thought to have been
a display structure which allowed other ammonites to tell “the
boys from the girls”. This one displays the lappet clearly. |
