Upper Cretaceous (Campanian)
Pierre Shale, Custer County, SD, USA
30mm nice small heteromorph.

Ammonite, Heteromorph. Cephalopod.

Spiroxybeloceras meekanum is a species of ammonite known from the Late Cretaceous (Upper Campanian).  It’s been found in various parts of the United States (South Dakota, Montana, Wyoming, New Mexico, Colorado, Nebraska, and Delaware) with a reported occurrence in Columbia.

Here’s your chance at an affordable example of a “hairpin” heteromorph. It’s one pf the oddities of the Pierre Shale.