Digesting an ancient ecosystem: coprolites from the Grippia bonebed, Lower Triassic, Svalbard

The marine Grippia bonebed from Vikinghøgda Formation, Lower Triassic, Svalbard is composed of scattered skeletal remains, teeth and coprolites. From this, five coprolite morphotypes have been identified and described. In this study 97 coprolites were examined and classified based on their morphology and inclusions. Thin sections, scanning electron microscope (SEM) and micro-computed tomography (micro-CT) were used to analyze the inclusions revealing skeletal material, fish scales and notably the first observations of invertebrates in this locality. Among the invertebrate components were sponge spicules, a fragment of a cephalopod shell and numerous onychites. Potential coprolite producers are evaluated and likely include chondrichthyans, osteichthyes, ichthyopterygians and temnospondyls. Additionally, this research provides a CT-scanning method for identifying low-density inclusions such as onychites and contribute to a better understanding of the marine Early Triassic paleoecosystem and food web on Svalbard.