Fig. 2From: Ultramicrostructural reductions in teeth: implications for dietary transition from non-avian dinosaurs to birdsTXM image showing the internal structure of a sectioned teeth from Paraves: aTroodontid, bAnchiornis, c and d Microraptorine 1 and 2, e Enantiornithine (indet.), f indet. Ornithurine, gLongipteryx and hSapeornis. Abbreviations: Ena, enamel; EDJ, enamel-dentin junction; IGS, interglobular porous space structure. The IGS layer is clearly present in the EDJ region of the serrated teeth of Microraptorine (c) and Troodontidae (a and b). The loss of IGS is labeled with a gray barBack to article page