Trace fossil classification explores how scientists group trace fossils by their form, function, and origin. It examines key approaches—taxonomic, ethologic, and toponomic—and highlights why no single system fully captures the diversity of trace-making behaviors. ...

Ichnofacies, recurring trace fossil assemblages in specific environments, illuminate past ecosystems. This article briefly describes invertebrate and vertebrate types, viewed as ecological patterns shaped by environment and fauna evolution. ...