The various ichnospecies of
Diplocraterion provide a good example of how
ethology (animal-substrate interactions and behavior) can be interpreted from trace fossils.
Diplocraterion is a classic example of equilibrichnia (equilibrium traces). These types of traces represent gradual adjustments to background sedimentation and erosion rates and reflect the efforts of the organisms to maintain a specific depth within the substrate. This movement within the substrate produces the two types of spreite (protrusive and retrusive) characteristic of
Diplocraterion and other ichnotaxa (e.g.,
Rhizocorallium). Most
Diplocraterion show only protrusive spreit (e.g.,
D. parallelum, D. polyupsilon, D. biclavatum). These indicate that the trace was produced under predominantly erosive conditions where the organism was constantly burrowing deeper into the substrate as sediment was eroded from the top.
D. yoyo has both protrusive and retrusive spreiten indicating highly variable conditions (erosional and depositional) leading to the need for the organisms to constantly adjust itself up and down within the substrate to maintain equilibrium and not become exposed or buried. ==See also==