npj Palaeoecosystems is an open access journal that considers research exploring all aspects of deep-time ecosystems in both marine and terrestrial realms. This journal aims to advance our understanding of the origins, biodiversity variation, and reconstruction of palaeoecosystems by exploring palaeobiology, palaeogeography, palaeoenvironment, stratigraphy, and other global aspects, including geodatabases, carbon cycle, and geological events, using multidisciplinary approaches. This journal covers a broad range of topics, which include, but are not limited to: • Palaeobiology, including palaeobotany and palynology, palaeo-invertebrate and palaeovertebrate zoology, palaeomicrobiology, and palaeobiodiversity. • Stratigraphy, including biostratigraphy, ecostratigraphy, chemostratigraphy, magnetostratigraphy, cyclostratigraphy, and chronostratigraphy as well as high-resolution archives for exploring ecosystem variations • Human origins and evolution primarily involve the study of ancient human fossils, associated strata and dating, fossil burial processes, and the ecological environments in which early humans lived. Methodologies used in this field include the analysis of ancient DNA, ancient proteins, and dietary composition. • Palaeogeography and palaeoenvironment, including sedimentology, geochemistry, palaeoclimate, and the cycling of carbon and other essential life elements • Ecosystem aspects of major geological events, such as terrestrial and marine mass extinction, global warming, anoxia and hypothermal events, wildfires, and volcanism activities • Macroevolution and macroecology, including sudden and long-term processes, relationships between palaeobiodiversity, disparity, and function, ecosystem evolution and stability in times of crisis and in normal times • Ecosystem reconstruction in both deep and modern times, as a catalogue for habitable Earth.