Fig. 1 in Distribution of the dentary groove of theropod dinosaurs: Implications for theropod phylogeny and the validity of the genus Nanotyrannus Bakker et al., 1988

Fig. 1. Lateral views of theropod skulls demonstrating presence or absence of the dentary groove. The dentary groove is present in the primitive theropod (A) Coelophysis bauri (NMMNH P-42200), as well as in the derived theropod (B) Compsognathus longipes (BSP AS I 563). The dentary groove is present in the tyrannosaurids (C) Gorgosaurus libratus (TCM 2001.89.1) and (D) Nanotyrannus lancensis ("Jane"; BMR P2002.4.1). The dentary groove is absent in both (E1) young (LACM 28471) and (E2) adult ("Sue"; FMNH PR2081) Tyrannosaurus rex. Arrows indicate the position of the groove, when present. Scale bars equal 5 cm.