Behavioral cladistics of trace fossils: evolution of derived trace-making skills

There is a genetic basis for many fundamental behaviors exhibited by animals (e.g., characteristic feeding patterns, defense instincts and social structures), which have the potential for leaving a trace fossil record. Behavioral cladistics may help us to better understand the evolutionary underpinnings of burrowing patterns and perhaps also the ichnotaxonomic relationships of complex and compound burrow systems. In an ichnologic cladogram, the shared homologous characters that define the branch points in the cladogram represent the expression of increasingly more derived behavior patterns, so a cladogram can depict evolutionary relationships of behavioral components reflected in some common trace fossils. Trace fossil cladograms allow us to conceptualize the acquisition and development of inherited skills for producing various kinds of traces throughout geologic time, and they give us an organized framework for interpreting the evolution of fossil behavior.