Eocene Age Fossil Bird Tracks - Green River Formation, Utah

This is a plate of shale with several Eocene aged, fossil bird tracks from the Green River Formation. These tracks are considered to be from birds such as sandpipers or plovers and were left on the southwestern shore of ancient lake Uinta nearly 50 million years ago. These tracks are now preserved in platy, limestone horizon known as the "Soldier Summit Fossil Track Horizon".

The abstract for an old paper describing these tracks can be found at https://www.jstor.org/stable/1302292?seq=1#page_scan_tab_contents