My research encompasses palaeontology (from systematics and phylogeny to palaeoecology), palaeobiogeography, palaeogeography, stratigraphy and sedimentary geochemistry. A substantial part of my work focuses on interpreting the history of life and its fossil record in the Cambrian and Ordovician periods, as well as on improving the high-resolution calibration of geological time across these intervals using multiple chronostratigraphic approaches. Collectively, these efforts have enabled me to address a wide spectrum of palaeobiological and geological questions and have resulted in more than 150 published papers and books.

At present, I am engaged in several projects of broad thematic and geographical scope. These fall into five main research areas: (1) The Ordovician deep-water shelf successions of Baltica – stratigraphy, faunal turnovers and palaeoenvironmental changes. (2) Cambrian chronostratigraphy and intercontinental correlation. (3) Cambrian palaeogeography and palaeobiogeography. (4) Trilobite palaeobiology – functional morphology, life habits, ontogeny, and evolution. (5) The Alum Shale Formation of Scandinavia – stratigraphy, faunas and depositional environments. These projects involve extensive collaboration with colleagues across Europe, North America and Asia.

From 2020 to 2022, I served as Chair of the International Subcommission on Cambrian Stratigraphy (ISCS). The primary objectives of the ISCS are to define the series and stages of the Cambrian by means of the internationally agreed rules of the International Commission of Stratigraphy (ICS), and to provide an international forum for scientific discussion and exchange on all aspects of Cambrian research.