Ammonoids And Orthocone Nautiloids Figured From United States Geological Survey Professional Paper 483-A California Carboniferous Cephalopods by Mackenzie Gordon Jr., 1964
Orthocone nautiloid from the Upper Mississippian Perdido Formation, Rest Spring Gulch, Death Valley National Park. Side and ventral views of the holotype specimen of Mithorthoceras clinatum. Figures 22 and 23 from Plate 1; they are greatly magnified. |