Three-dimensional reconstruction of the skull of Helminthophis flavoterminatus (AMNH R 59407), based on HRXCT data. A. Lateral view; B. Dorsal view; C. Ventral view with the lower jaw partially digitally removed; D. Anterior view; E. Posterior view. Scale bar: 1 mm. Anatomical abbreviations: a, angular; bo, basioccipital; cb, compound bone; cbp, compound bone prearticular component; cbs, compound bone surangular component; co, coronoid; d, dentary; ec, ectopterygoid; en, external naris; f, frontal; fo, foramen; fv, fenestra vomeronasalis; m, maxilla; mf, mental foramen; n, nasal; oc, occipital condyle; ooc, otico-occipital (fused prootic + opisthotic + exoccipital); p, parietal; pa, palatine; pbs, parabasisphenoid; pe, postorbital element; pf, prefrontal; pg, pterygoid; pm, premaxilla; q, quadrate; rp, retroarticular process; sf, surangular foramen; sm, septomaxilla; st, supratemporal; tf, trigeminal foramen; v, vomer; vf, vomerine foramen.