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.
Gastropod shells of marine animals are often preserved as fossils.
If ancient gastropod shells are found in a place then that place used to be covered by water.
the bones of what can be found to signify that place used to be covered by water?
* h2o
* living things
* dogs
* adult sea squirts
* bullfrogs
* humans
* an amoebae
* gastropod shells