Figure 5. A-C in Ontogeny of the skull of the blind snake Amerotyphlops brongersmianus (Serpentes: Typhlopidae) brings new insights on snake cranial evolution

Figure 5. A-C, posterolateral views of the otic region of Amerotyphlops brongersmianus throughout ontogeny: A, embryo at Stage 33; B, hatchling; C, adult. Black arrowheads indicate the suture between the exoccipital and opisthotic. D, endocranial view of the otic region in an embryo of A. brongersmianus at Stage 34 showing the crista interfenestralis concealing the crista tuberalis. E-F, endocranial and lateral views of the otic region of the embryo of Candoia bibroni showing the type 3 configuration of the crista circumfenestralis. G, lateral view of the otic region of the embryo of Naja oxiana showing the type 4 configuration of the crista circumfenestralis. Abbreviations: bo, basioccipital; ci, crista interfenestralis; cop, commissura praefacialis; cp, crista prootica; ct, crista tuberalis; ct+ci, fused crista tuberalis and crista interfenestralis; dp, descensus parietalis; jf, jugular foramen; ot, otooccipital; p, parietal; pbs, parabasisphenoid; po, prootic; pov, posterior opening of the Vidian canal; so, supraoccipital; st, stapes; V, foramen for the maxillary and mandibular rami of the trigeminal nerve; V2, foramen for the maxillary ramus of the trigeminal nerve; V3, foramen for the mandibular ramus of the trigeminal nerve; VII, foramen for the facial nerve. Scale bars equal to 1 mm.