Trace Fossil - Classification

Classification

Trace fossils are generally difficult or impossible to assign to a specific maker. Only in very rare occasions are the makers found in association with their tracks. Further, entirely different organisms may produce identical tracks. Therefore conventional taxonomy is not applicable, and a comprehensive form taxonomy has been erected. At the highest level of the classification, five behavioral modes are recognized:

• Domichnia, dwelling structures reflecting the life position of the organism that created it.
• Fodinichnia, three-dimensional structures left by animals which eat their way through sediment, such as deposit feeders;
• Pascichnia, feeding traces left by grazers on the surface of a soft sediment or a mineral substrate;
• Cubichnia, resting traces, in the form of an impression left by an organism on a soft sediment;
• Repichnia, surface traces of creeping and crawling.

Fossils are further classified into form genera, a few of which are even subdivided to a "species" level. Classification is based on shape, form, and implied behavioural mode.