arising from F. Saleh et al. Nature Ecology & Evolution https://doi.org/10.1038/s41559-024-02331-w (2024)

Saleh et al.¹ announced the Cabrières Biota as a new exceptionally preserved fossil assemblage (Konservat-Lagerstätte) of Early Ordovician age dominated by sponges and algae. New deposits of this type are needed to better understand Ordovician ecology and biodiversification and the Cabrières assemblage was presented as a major advance in knowledge of Ordovician polar communities¹. However, the specimens identified as sponges, algae, a worm, a hemichordate tube and a lobopod (that is, all of the non-arthropod exceptionally preserved taxa) appear to be trace fossils, mostly burrows containing faecal pellets. Thus, the Cabrières fossils do not constitute an exceptionally preserved assemblage and the conclusions relating to polar palaeoecology cannot be supported.