This dataset contains the areal extents of the SPA central cryptomaria analyzed in Wang et al. (2023), as shown in Figure 8. The data is in 'shafile' format and can be opened directly in ArcGIS software. The data is in the stereographic projection centered at the center of SPA (191.1°E, 53.2°S; Garrick-Bethell and Zuber, 2009). MinExt_SPACC=Minimum areal extent of the SPA central cryptomaria; MaxExt_SPACC=Maximum areal extent of the SPA central cryptomaria.