are fossils most often found in limestones?

Answer 1

www.wikipedia.org/wiki/Limestone
Yep...

Answer 2

The Latin word fossilis means: something dug out of the earth.In science this means: remnants of a living thing preserved in rock.Dust and sand of deserts and dry areas can conserve plants and animals or parts thereof. The same holds true for mud and sand at the bottom of the ocean, ice, peat-bog, swamp,sap of trees (amber) and volcanic ashes. The preserved plants and animals become over millions of years fossils.