Figure 1. Edmontosaurus cranial anatomy. 1, Left, lateral view; 2, Left, lateral view with quadratojugal and jugal removed from relevant skeletal elements; 3, Medial view of left half of skull with relevant skeletal elements labeled; 4, Caudal view of skull with relevant skeletal elements. Abbreviations: bj, basal joint; bpt, basipterygoid process; cp, coronoid process; dn, dentary; ect, ectopterygoid; fr, frontal; jj, jaw joint; ju, jugal; la, lacrimal; mx, maxilla; na, nasal; oj, otic joint; pal, palatine; po, postorbital; prdn, predentary; prmx, premaxilla; prp, preotic pendant; pt, pterygoid; pt, pterygoid; qj, quadratojugal; qu, quadrate; sa, surangular; sp, splenial; sq, squamosal.