Beg tse - skull and drawing. a Skull in lateral view. b Schematic drawing of skull in left lateral view. Abbreviations: af, antorbital fossa; an, angular; de, dentary; fr, frontal; j, jugal; la, lacrimal; mx, maxilla; na, nasal; or, orbit; pd, predentary; pf, prefrontal; pm, premaxilla; po, postorbital; qu, quadrate; sa, surangular.