Fallen Boulder Reveals 313M-Year-Old Fossil Footprints at Grand Canyon
Fallen Boulder Reveals 313M-Year-Old Fossil Footprints at Grand Canyon
Aug 23, 2020, 4:14am UTC
https://www.npr.org/2020/08/21/904943006/fallen-boulder-reveals-313-million-year-old-fossil-footprints-at-grand-canyon