If fossils of a water animal or plant are found in a place then that place used to be covered by water in the past, and barnacles are animals that live in the water. Given these facts, what fossils have to be found in a place to signify the place used to be covered by water among the following options:
- bullfrogs
 - Sediment
 - Sea urchins
 - dinosaurs
 - barnacles
 - humans
 - patch reefs
 - natural gas


 

     barnacles    