Trace Fossils

These tracks were made by ammonites that were dragged along the bottom of the lagoon. The currents were not strong enough to disturb the sediment but just strong enough to move the very bouyant ammonites. The ammonites have little chambers inside the shells that slowly fill with water and that causes them to sink. If there is a little air left in the shell it is partially bouyant and then the tinyest current can drag it accross the bottom of the lagoon (modified from Barthel et. al., 1990).
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