A review of biodiversity curves of marine organisms indicates that, despite fluctuations in amplitude (some large), a large-scale, long-term radiation of life took place during the early Palaeozoic Era; it was aggregated by a succession of more discrete and regionalized radiations across geographies and within phylogenies. This major biodiversification within the marine biosphere started during late Precambrian time and was only finally interrupted in the Devonian Period. It includes both the Cambrian Explosion and the Great Ordovician Biodiversification Event. The establishment of modern marine ecosystems took place during a continuous chronology of the successive establishment of organisms and their ecological communities, developed during the ‘Cambrian substrate revolution’, the ‘Ordovician plankton revolution’, the ‘Ordovician substrate revolution’, the ‘Ordovician bioerosion revolution’ and the ‘Devonian nekton revolution’. At smaller scales, different regional but important radiations can be recognized geographically and some of them have been identified and named (e.g. those associated with the ‘Richmondian Invasion’ during Late Ordovician time in Laurentia and the contemporaneous ‘Boda event’ in parts of Europe and North Africa), in particular from areas that were in or moved towards lower latitudes, allowing high levels of speciation on epicontintental seas during these intervals. The datasets remain incomplete for many other geographical areas, but also for particular time intervals (e.g. during the late Cambrian ‘Furongian Gap’). The early Palaeozoic biodiversification therefore appears to be a long-term process, modulated by bursts in significant diversity and intervals of inadequate data, where its progressive character will become increasingly clearer with the availability of more complete datasets, with better global coverage and more advanced analytical techniques.

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Land plants comprise the bryophytes and the polysporangiophytes. All extant polysporangiophytes are vascular plants (tracheophytes), but to date, some basalmost polysporangiophytes (also called protracheophytes) are considered non‐vascular. Protracheophytes include the Horneophytopsida and Aglaophyton/Teruelia. They are most generally considered phylogenetically intermediate between bryophytes and vascular plants and are therefore essential to elucidate the origins of current vascular floras. Here, we propose an alternative evolutionary framework for the earliest tracheophytes. The supporting evidence comes from the study of the Rhynie chert historical slides from the Natural History Museum of Lille (France). From this, we emphasize that Horneophyton has a particular type of tracheid characterized by narrow, irregular, annular and/or, possibly spiral wall thickenings of putative secondary origin, and hence that it cannot be considered non‐vascular anymore. Accordingly, our phylogenetic analysis resolves Horneophyton and allies (i.e. Horneophytopsida) within tracheophytes, but as sister to eutracheophytes (i.e. extant vascular plants). Together, horneophytes and eutracheophytes form a new clade called herein supereutracheophytes. The thin, irregular, annular to helical thickenings of Horneophyton clearly point to a sequential acquisition of the characters of water‐conducting cells. Because of their simple conducting cells and morphology, the horneophytophytes may be seen as the precursors of all extant vascular plant biodiversity.