TAXONOMIC REPRESENTATION IN THE FOSSIL VERSUS MODERN BEHAVIORAL RECORDS

Biologists and paleontologists are both interested in animal behavior. Not all living animal behaviors have been the equal focus of study. Birds and mammals are overrepresented in studies of extant behaviors, especially those involving communication, sociality and mating (Rosenthal et al. 2017). Invertebrate behavioral studies have focused mainly on insects. Very few other taxa have been examined. Here, we evaluate whether similar biases exist in paleontological studies of behavior, which are primarily based on trace fossils, functional morphology, and snapshots of “frozen behavior.” Dinosaur tracks, and other tetrapod tracks to a lesser extent, represent the charismatic fauna of ichnology, receiving exceptional attention. Another area of concentration is the traces of benthic marine invertebrates (including numerous indeterminate worm-like taxa) owing to their availability and abundance in the rock record. These behaviors include those rarely studied in the modern, such as drilling predation. Other studies of preserved activities, such as those summarized in The Fossil Behavior Compendium (Boucot and Poinar 2010), cover a much wider range of fossil taxa and behaviors than the ichnofossil record.

Integrating behavioral studies of modern animals with those of extinct organisms is limited by their disparate taxonomic foci and by limits on the accessibility and availability of evidence. Communication and social displays of terrestrial birds, for example, are a staple of modern behavioral ecology, but have very low preservation potential. On the other hand, deep sea trace fossils are commonly studied by ichnologists, but modern examples are generally inaccessible and little studied by behavioral biologists.