Fig. 3 in Ammonoid biodiversity changes across the Cenomanian-Turonian boundary in the Yezo Group, Hokkaido, Japan

Fig. 3. Correlation of Upper Cretaceous δ13C stratigraphy of terrestrial organic materials in the Mikasa, Obira, and Oyubari areas, Japan and reference δ13C stratigraphy of carbonates in Europe (after Jarvis et al. 2006). Six carbon isotopic units (CIUs) were identified in the present study. Abbreviations: e., early; m., middle; PDB, Pee Dee Belemnite Standard; Aj, Acanthoceras jukesbrownei; An, Actinoceramus nipponicus; Ar, Acanthoceras rhotomagense; Ca, Calycoceras spp.; Cg, Calycoceras guerangeri; Ci, Cunningtoniceras inertme; Cu, Cunningtoniceras spp.; Cw, Collignoniceras woollgari; Fc, Fagesia catinus; Ih, Inoceramus hobetsensis; Ik, Inoceramus kamuy; Md, Mantelliceras dixoni; Mg, Metoicoceras geslinianum; Mn, Mammites nodosoides; Nj, Neocardioceras juddii; Wd, Watinoceras devonense.