Marine fossils are the preserved remains or traces of organisms that lived in ocean environments millions of years ago. These fossils can include shells, bones, and even imprints of soft-bodied creatures. They provide valuable information about ancient marine ecosystems and the evolution of life in the sea. Common types of marine fossils include those from mollusks, corals, and fish. Scientists study these fossils to understand changes in climate, sea levels, and biodiversity over geological time. Marine fossils are often found in sedimentary rock layers, which form from the accumulation of sediments in oceanic environments.