Sea turtles spend most of their lives at sea feeding on jellyfish. When it is time to lay their eggs, mature females come ashore. They dig nests in the sand along the coast, lay their eggs, and then return to the sea. The data below show the changing sea levels since the late
1800s.

Crinoids, also known as sea lilies, appear to be sea plants but are not plants at all. crinoids are an echinoderm species which uses anchoring structures called holdfasts to attach themselves to the sea floor. crinoids were most abundant in pennsylvania during the mississippian period, which ranged from 375 to 320 million years ago. fossils of the crinoids shows that during most of this time pennsylvania was that provided favorable conditions for crinoid growth. a) glacial terrain b) a dry and sandy plain c) mostly mountain ranges d) covered by warm, shallow seas