Fossil Leaf, Glendive Montana

 Beringiaphyllum cupanioides

    Fort Union Formation

    Glendive, Montana

    Paleocene

Fort Union Formation leaf fossils from the Paleocene epoch (approx. 60 million years old) are commonly and naturally brown, ranging from dark brown to reddish-orange. These fossils are usually preserved as iron-stained impressions or carbonizations in shale or siltstone, creating a high-contrast brown-on-gray appearance.