Fig. 3From: 3-D orientation and distribution of ammonites in a concretion from the Upper Cretaceous Pierre Shale of Montana“Sculpture” of ammonites in the east-central part of the concretion shown in three views, side from south (a), high oblique from south (b), and top (c). The side view includes an outline of the concretion relative to the sculpture. The arrows in the high oblique view indicate the angle and direction of dip of the ammonites. The specimen marked “1” is thought to be the first ammonite to have settled on the bottomBack to article page