ribstone

plural ribstones

1. A petroglyph in the form of an animal's rib cage.

   Most of the ribstones in Alberta are rounded humps, a bit like a buffalo itself, but there are some in Saskatchewan where the pattern of backbone, ribs, hoofs and pockmarks is inscribed on flat, almost triangular slabs.

   2005, Liz Bryan, The Buffalo People, page 85

   1 more example

   Virtually all of the formal investigations of the Alberta ribstones have led to conclusions of great antiquity. Many of the ribstones are of quartzite, one of the hardest rocks known. These monoliths exhibit advanced erosion and deep patination.

   2004, Carol Diaz-Granados, James R. Duncan, The Rock-Art of Eastern North America, page 142