UK Ammonite Jeletzkytes IF-UKA-16-001

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

This is a splendid example of the macroconch form of this ammonite.  It displays excellent suture pattern along with beautifully preserved purple iridescent shell.  The shell is 4.5 inches in diameter at its widest point. The specimen has some very minor repair.
The genus has variable macroconch shape but is dominantly stout with quadrate to slightly depressed aperture.  The body chamber has strong locally clavate ventrolateral tubercles usually with bullae below the umbilical shoulder and scattered flank tubercles/bullae on the hook.  The phagmocone has up to four rows of tubercles or none.  The Last whorl of the microconch is more loosely coiled commonly with a mid-flank row of tubercles on the body chamber.  The phragmocone is variously tuberculate.
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.