The original Manzano Group was historically important in the establishment of the paleontological time scale of the Permian period in western North America.

[5][6] The group consists of Statherian lithostratigraphic units exposed in the Los Pinos Mountains and nearby ranges of central New Mexico.

These are mostly metarhyolite or quartzite units with some schist and amphibolite, and form a sequence in excess of 2,700 meters (8,900 ft) thick.

[7] Study of the group also provides evidence in favor of the hypothesis that the Mazatzal Province was formed by continental arc volcanism from Yavapai crust.

This placed the fossils in the upper Pennsylvanian as defined in western North America at that time, and Boese recommended abandonment, or at least heavy revision, of the Manzano Group.