Plant Trace Fossils
Description: The most common trace fossils left by plant activity are root traces, which show the branching and irregular morphology normally associated with living plant roots. Although some people may regard these as body fossils because they are typically preserved as casts of roots, the original root structure was formed as a biogenic structure while the organism was still alive and connotates behavior (growth). Thus, I regard root traces as trace fossils. In contrast, a mold or cast of a tree trunk that was buried in a mudflow would be a body fossil because the tree was not growing through the mudflow deposit.
The following two images are of a modern creeping vine, Ambrosia hispida, in sediment composing a dune and root traces left by a similar vine in the Holocene Rice Bay Formation, respectively. Both are on San Salvador Island, Bahamas.
Modern Roots
Root Trace
Fossils
The following images are also of root trace fossils in the Grotto Beach Formation, San Salvador Island, Bahamas. These trace fossils are the best preserved root traces I have ever seen; they are exquisitely preserved and look so similar to modern roots, it was startling to touch them and find out that they were petrified. The taphonomy regarding their preservation was probably through early cementation around the original roots (forming external molds), followed by cementation of carbonate sand that filled the molds (making casts of the original root structures).
Back to Trace Fossil Images Page
Back to ENVS Main Page