Jeletzkytes nebracensis
Fox Hills Formation POAZ Trail City Mbr.
Upper Cretaceous (Maastrichtian)
Corson County, South Dakota

Here is classic specimen of a complete Jeletzkytes nebrascensis in its original limestone concretion. The shell excellent iridescence typical of this locality. The suture pattern is visible through thin shell oat several spots This is the macroconch form. The specimen is the only ammonite in this concretion and both halves are included with the purchase. The ammonite is 14 cm across. This is a classic example from the locality. There is no repair or restoration.
The macroconch of this species is compressed and the last whorl is markedly higher than wide. The phragmocone is conspicuously tuberculate with strong ventrolateral tubercles and five to seven rows of weaker flank tubercles which commonly extend onto part or all of the body chamber. The microconch is variably tuberculate commonly with double row of umbilical tubercles or bullae.
The Trail City Member of the Fox Hills Formation is a light-grey clayey silt that forms the lower 65 - 210 feet of the formation in the type area. It contains several limestone concretion zones with a rich ammonite and pelecypod fauna.