Ammonites from the Prionocyclus wyomingensis Biozone
Prionocyclus wyomingensis Meek 1876
gracile
form
of Prionocyclus wyomingensis from the upper part of the Juana
Lopez Member of the Mancos Shale
at localities east of Ferron to Southeast of Green River, Utah.
The one on the left is 58mm and the one on the right is 71mm
gracile
form 76mm dia, close to P. novimexicanus, from east of Clawson
robust form of Prionocyclus
wyomingensis, 37mm
robust
form of Prionocyclus wyomingensis 32mm. lateral and
ventral view.
a large adult specimen from concretions in the Frontier Formation east
of Vernal.
320 mm dia., the gracile form.
Scaphites
ferronensis Cobban 1951
from the upper part of the
Juana Lopez Member of the Mancos Shale
at localities east of Ferron to Southeast of Green River,
The one on the left is 46mm long, the one on the right is 37mm long
Pteroscaphites pisinus Cobban
1952, next to a larger Scaphite (S.
cf. S. whitfieldi)