Fig. 3: Spatio-temporal development of relative oxygen conditions in Baltoscandia.
From: Oxygenation of the Baltoscandian shelf linked to Ordovician biodiversification
a–h, Time series illustrating the spatio-temporal development of relative oxygen conditions (I/Ca) across the Baltoscandian shelf. a, Stippled lines indicate generalized shelf features (Fig. 1b) for reference. Opaque red circles indicate localities included in data processing and map projections. Arrows indicate dominant water current directions, based on cephalopod conch orientations (Supplementary Information sections 2 and 5). The I/Ca data patterns indicate that the levels of dissolved oxygen increased in the shelf sea and that relatively oxygen-rich waters spread onto Baltica through time and migrated towards the south and west (modern-day directions). Credit: basemaps, data from EEA, VZD, Esri, Here, Garmin, FAO, NOAA, USGS; maps created using ArcGIS software by Esri (www.esri.com).
