Figure 6. A-B in Ontogeny of the skull of the blind snake Amerotyphlops brongersmianus (Serpentes: Typhlopidae) brings new insights on snake cranial evolution

Figure 6. A-B, internal (endocranial) view of the parabasisphenoid bone in Amerotyphlops brongersmianus throughout ontogeny showing the conformation of the Vidian canal: A, embryo at Stage 33; B, adult. C, endocranial view of the parabasisphenoid bone of the embryo of Liasis mackloti. D, frontal cutaway posterior to the hypophysial fenestra of embryo of A. brongersmianus at Stage 33 showing the cartilaginous nuclei of the trabeculae cranii. E-F, internal views of a sagittal cutaway of the skull of A. brongersmianus throughout ontogeny showing different endocranial apertures of the Vidian canal and presence of the lateral wing of the parabasisphenoid: E, embryo at Stage 33; F, adult. G, lateroventral view of the adult skull of A. brongersmianus showing external apertures of the Vidian canal. H-I, internal views of a sagittal cutaway of the skull of Candoia bibroni throughout ontogeny showing different endocranial apertures of the Vidian canal and the lateral wing of the parabasisphenoid: H, embryo; I, adult. J, lateroventral view of the adult skull of C. bibroni showing external apertures of the Vidian canal. Abbreviations: bo, basioccipital; cbc, cerebral carotid artery; ccf, cerebral carotid foramen; fr, frontal; lo, lateral ossification of the posterior trabecula; ot, otooccipital; p, parietal; pan, palatine nerve; par, palatine artery; pav, primary anterior opening of the Vidian canal; pbs; parabasisphenoid; po; prootic; pov, posterior opening of the Vidian canal; sav, secondary anterior opening of the Vidian canal; t, trabecula cranii; tc, trabecula communis; V, foramen for the maxillary and mandibular rami of the trigeminal nerve; V4, cid nerve; VIIp, palatine ramus of the facial nerve. Scale bars equal to 1 mm.