PERISPHINCTES AMMONITE– LARGE

Dick: Thanks for sharing the details of this large Perisphinctes specimen with me.  It is an Upper Jurassic (Upper Oxfordian) ammonite from Morocco.  It matches W.J. Arkell’s Treatise description.  “Large to gigantic, whorls quadrate; inner and middle whorls sharply ribbed, with sudden change at outer whorl to strong, coarse, distant, ridge or wedge-shaped primaries.”  North Africa is listed as a common location.  I include here your picture of the specimen you have for sale and below the “type” image from the Treatise On Invertebrate Paleontology.

Perisphinctes

This large ammonite will certainly make a nice geologically inspired decorative item.

Phil Dunton
Manzanita Lab, Tucson