Paleocene Mammals and Albert Silberling

The panel gives Ptilodus the life span of its whole order. Multituberculates as a group lasted from the Jurassic to about 35 million years ago, but Ptilodus is a Paleocene genus and never met a sauropod, and the panel's Paleozoic means Paleocene. Its Montana species came from these quarries. Earl Douglass, working for Princeton, found Fort Union mammals east of the Crazies in 1901, settling the formation's disputed age, and in 1908 named Ptilodus montanus from the Silberling Quarry, with Picrodus silberlingi for the homesteader who dug there.

Where it stands

More markers nearby

• The Crazy Mountains — steps away