ichnotaxonomy

Ichnotaxonomy is the branch of paleontology that classifies trace fossils, or ichnofossils, which are records of the behavior of organisms rather than the organisms themselves. Traces include footprints, trackways, burrows, borings, feeding marks, and nests preserved in sedimentary rocks. Ichnology studies these traces to infer behavior, locomotion, and interactions with the environment, and uses a formal naming system to organize the diversity of traces.

In ichnotaxonomy, classifications are based on the morphology of the trace rather than the identity of the producer. The primary ranks are ichnogenera and ichnospecies, collectively called ichnotaxa. Examples of well-known ichnogenera include Grallator, Diplichnites, and Cruziana. An ichnogenus groups traces with a similar overall form, while an ichnospecies refines that group with differences in detail, such as size or specific trackway patterns. It is common for a single organism to produce multiple trace types, and for similar traces to be produced by different organisms, so ichnotaxonomy focuses on form and behavior rather than biological affinity.

Nomenclature of ichnotaxa generally follows the conventions of zoological naming, but the names describe traces, not the producers. Type specimens and published descriptions define each ichnotaxon, and researchers often note the substrate, depth, and sedimentary context to aid interpretation. Preservation biases and convergent morphologies frequently complicate assignments, requiring careful comparison of trackway features, digit impressions, pace, and stride.

Ichnotaxonomy provides a framework for comparing ancient behavioral patterns across time and space, contributing to reconstructions of paleoecology and the dynamics of past ecosystems.