Abbreviations: Bso, basioccipital; bpt.pr, basipterygoid process; Bsp, basisphenoid; b.t., basal tubera; Exo, exoccipital; F, frontal; i.c, groove for the inter carotid; Lsp, laterosphenoid; m.pr, median process; ol.t, olfactory tract; Op, opisthostic; Osp, orbitosphenoid; P, parietal; Pro, paroccipital; prcp.pr, precotyloid process; Po, postorbital; Pr, prootic; Prsp, presphenoid; Psp, parasphenoid; q.c, quadrate cotylus; Spo, spraoccipital; s.cr, sagittal crest; Sq, squamosal.
Source: wiktionary