Figure 4 in Ontogeny of the skull of the blind snake Amerotyphlops brongersmianus (Serpentes: Typhlopidae) brings new insights on snake cranial evolution

Figure 4. Lateral (left), anterior (centre) and ventral (right) views of the egg tooth of squamate embryos at equivalent pre-hatching stages: A, Lanthanotus borneensis; B, Amerotyphlops brongersmianus; C, Liasis mackloti; D, Naja oxiana. The premaxilla is highlighted in light grey. The ventral view is a horizontal cutaway showing the section of the egg tooth near its base. Scale bars equal to 1 mm.