What fossils are found in sedimentary rock?

Answer 1

The vast majority of visible fossils are marine invertebrates, animals that live in the sea and have no backbone, mostly animals with a hard outer shell. This would include clams, coral, brachiopods, ammonites, and other animals familiar to us, as well as extinct animals like trilobites and crinoids. In some locations the deposits are dominated by fish fossils and more rarely insects.

Answer 2

Almost all fossils are found in sedimentary rock.

Only rarely do you find fossils in igneous rocks such as when cooling lava envelopes a tree trunk. The fossils that you might find in metamorphic rock are so distorted from pressure and temperature that they are usually unrecognizable. Some fossils result from petrification where leaching minerals replace the organic matter and some fossils form when tree sap (amber) envelopes the organism.

Answer 3

Sedimentary rocks often contain fossils of organisms that lived in the past, such as ammonites, trilobites, and dinosaurs. These fossils get preserved when minerals from the surrounding sediments replace the original organic material in the organism, leaving behind a cast or impression of the organism.