Figure 5
From: Developmental and evolutionary novelty in the serrated teeth of theropod dinosaurs

Microanatomy of unerupted cf.
Gorgosaurus sp. teeth. (A) Distal carina of CMN 2225 showing the deep folds at the base of each interdental sulcus. (B) Detail of interdental fold from (A) showing absence of sclerotic dentine. (C) Dentine tubules in an erupted tooth (ROM 57981) showing peritubular dentine in each hollow tubule. (D) Dentine tubules in an unerupted tooth (CMN 2225) showing less peritubular dentine when compared to erupted tooth in (C). (E) Transverse section between two neighbouring denticles (CMN 2225), carina to the top. (F) Transverse section through a denticle showing absence of globular dentine in the denticle tip. Carina to the right. (G) Unerupted tooth of cf. Gorgosaurus libratus (RTMP 2012.012.0029), with interdental folds. (H) Unerupted tooth of Allosaurus fragilis (UMNH.VP 23761), with interdental folds. Abbreviations: dt, dentine tubule; e, enamel; gd, globular dentine; if, interdental fold; is, interdental sulcus; pd, primary dentine.