What are Phytoliths? Phytoliths, Greek for “plant stones,” are microscopic particles composed of silica that are made by many plants. There are many factors that influence the size and shape of phytoliths. Plants may produce phytoliths under normal conditions or as a response to injury from insects, microbes, or mechanical damage. Because phytoliths are very durable and most are identifiable to particular plants, they can be used in a variety of environmental studies. The fossil record of phytoliths may extend back to the Silurian. First known fossil occurrence: Silurian. Last known fossil occurrence: Quaternary. This group has living relatives. Cool Phytoliths links: Search for images of Phytoliths on Google |