Mark Wilson June 10th, 2012 These rounded stones are labeled in
our collections as gastroliths (literally “stomach stones”) from
Starr Springs near Hanksville, Wayne County, Utah. I’m featuring
them this week in honor of our Utah Project team working right
now in the baking Black Rock Desert near Fillmore, Utah. From
their reported location, these stones are likely out of the
Summerville Formation (Middle-Upper Jurassic) and, in another
plausible supposition, probably from some sort of dinosaur.
Sometimes we just have to trust the labels on our specimens, at
least for educational purposes! My friend Tony Martin recently
wrote an excellent blog post on gastroliths, so I won’t repeat
his insights here. The general wisdom is that these stones were
consumed by herbivorous dinosaurs to aid in their digestion.
They would have lodged them in the equivalent of a gizzard and
used them to grind their food, much like modern birds. (And yes,
dinosaurs were birds themselves.) Gastroliths usually have a
resistant lithology