Dubiocoprolite

Butterfly Eject
Fossil Type: 
Composition: 
Location: 
UT
United States
Utah US
Formation: 
Period: 
Dimensions: 
8" x 5" x 5/16"
Weight Freeform: 
455 g

Many times stones of this type are sold as coprolites or "gem coprolites" attributed to herbivore dinosaurs. Whether this type of rock has a fecal origin is in question. Nevertheless, they are quite beautiful. If this is a coprolite, the stones that look like butterfly wings would most likely be gastroliths.  Gastroliths (or gizzard stones) are stones ingested by herbivores to aid in digestion.