Describe the fossils found in the top layers of the Grand Canyon.

Sedimentary fossils/rocks

Explanation:

The sedimentary rocks exposed throughout the canyon are rich with marine fossils such as crinoids, brachiopods, and sponges with several layers containing terrestrial fossils such as leaf and dragonfly wing impressions, and footprints of scorpions, centipedes, and reptiles. Sedimentary rocks are formed from pre-existing rocks or pieces of once-living organisms. They form from deposits that accumulate on the Earth's surface. Sedimentary rocks often have distinctive layering or bedding.

poor water quality affects most estuarine organisms, including commercially important fish and shellfish. the pollutants that have the greatest impact on the health of estuaries include toxic substances like chemicals and heavy metals, nutrient pollution (or eutrophication), and pathogens such as bacteria or viruses.

the element that provides strength to the exoskeletons of clams and oysters is phosphorus. this is so because calcium carbonate is the main component in the shells.

explanation: