Misplaced trace fossils in unlikely environments

Graphoglyptids are trace fossils that are generally acknowledged to have had a deep-sea origin, displaying complex, nutrient gathering strategies in response to stable environments with low productivity. However, two recently discovered graphoglyptids in the Permian of New Mexico seem to challenge previous assumptions. Rather than in deep-sea sediments, Spirorhaphe azteca and Augerinoichnus helicoidalis were discovered in tidal flat palaeoenvironments, showing that these behavioural patterns are also carried out by animals in tidal settings. Fine sediments of the region are recognized as the key factor in the preservation of these trace fossils. Presence of graphoglyptids in a transitional environment demonstrates that behaviour is not solely defined by depth, but many intricate factors are involved.