Paleontologist Anthony Romilio looked at three rock slabs bearing footprints. Most of the footprints come from one slab, which was discovered in 2002.

This article was originally published on NBCNews.com Paleontologist Anthony Romilio inspects a boulder Tuesday in a carpark near the town of Biloela, in central Queensland.

For two decades, Australian students walked by the 5-foot-long boulder in their school’s foyer unaware of its significance. When paleontologist Anthony Romilio finally inspected the roughly 200 ...

"They did not know that this was an actual fossil itself. Some were thinking that it was a replica," Australian paleontologist Anthony Romilio said.

Paleontologist Anthony Romilio inspects a boulder Tuesday in a carpark near the town of Biloela, in central Queensland. University of Queensland ...