sentence: Many limestones contain fossils, and some are made up almost entirely of skeletal material.
sentences_after: Limestone is not found much before the Cambrian period, because shelled animals had not yet evolved. Small shelly fossils occur in the latest Ediacaran for the first time.
concept_name: limestone
headings: Limestone Fossiliferous limestones
categories: Carbonate rocks Sedimentary rocks