replying to L. A. Muir & J. P. Botting Nature Ecology & Evolution https://doi.org/10.1038/s41559-024-02559-6 (2024)

The Cabrières Biota (France) is a new diverse fossil assemblage that provides insights into Ordovician polar ecosystems¹. This assemblage comprises fossils of algae, sponges, cnidarians, trilobites, non-biomineralized arthropods, molluscs, brachiopods, hyoliths, hemichordates, worms and lobopodians¹, as well as trace fossils. Muir and Botting² question whether the site is a Lagerstätte by reinterpreting sponges, algae, hemichordates, worms and cnidarians as trace fossils. Here we show that their arguments do not follow an evidence-based approach and the specifics of their trace fossil claims do not engage with the standard protocols for distinguishing between trace and body fossils. We provide comprehensive evidence that the Cabrières Biota is a diverse and exceptionally preserved fossil Lagerstätte including algae and animals, representing a high-latitude refugium during the warm Early Ordovician.