Fig. 4

Skull and tooth jaw of Hesperosaurus mjosi (SMA 0092, specimen “Lilly”), from the Kimmeridgian–Tithonian (Late Jurassic) Morrison Formation of Howe-Scott Quarry, Howe Ranch, near Shell (Big Horn County, Wyoming, USA). a Skull in left lateral view. b Magnified lateral view of the left jaw, with very well-preserved teeth, including several maxillary teeth still in original position, and possibly some displaced dentary teeth in the posterior part. d dentary, mx maxilla. Scale bars 1 cm (b), 10 cm (a)