Prionocyclus novimexicanus
Biozone
Prionocyclus novimexicanus (Marcou) 1858
gracile
form of Prionocyclus novimexicanus the one on the left
is 58mm and the one on the right is 50mm
gracile form of Prionocyclus novimexicanus, 58mm
robust
form of Prionocyclus novimexicanus
The one on the left with some nacreous shell is 47mm dia.
The specimen on the right is 73mm dia., it shows the sutures well.
the robust form, 117mm dia.
all from the Mancos Shale southeast of Green River
The one on the left with some nacreous shell is 47mm dia.
The specimen on the right is 73mm dia., it shows the sutures well.
the robust form, 117mm dia.
all from the Mancos Shale southeast of Green River
Scaphites whitfieldi Cobban 1951
46mm long
38mm long
from concretions in the lower part of the main body of the Mancos Shale southeast of Green River.
Baculites yokoyamai Tokunaga and Shimizu 1926
86mm long, 13mm at the aperture, from the Mancos Shale southeast of Green River.