Fig. 4.

Chondrocranium of Ptychoglossus bicolor at stage 39. Dashed lines denote subjacent cartilage and dark-gray structures denote ossified cartilage. (A) Dorsal view. (B) Lateral view. Abbreviations: ac, aditus conchae; apps, anterior process of planum supraseptale; ar, articular; asp, ascending process of pterygoquadrate; bf, basicranial fenestra; bo, basioccipital; bpt, basipterygoid process; bsp, basisphenoid; ch, cartilago hypochiasmatica; crs, crista sellaris; ec, extracolumella; eo; exoccipital; fe, foramen epiphaniale; fep, fenestra epioptica; fhn, hypoglossal foramina; fn, fenestra narina; fo, fenestra olfactoria; fop, fenestra optica; fpr, fenestra prootica; fs, fenestra in nasal or interorbital septum; gq, gap in quadrate; ic, intercalary; is, interorbital septum; lps, lateral process of paraseptal cartilage; lta, lamina transversalis anterior; Mc, Meckel's cartilage; ns, nasal septum; onf, orbitonasal fissure; op, opisthotic; pacc, pila accesoria; pai, processus alaris inferior; pas, processus alaris superior; pat, ascending process of tectum; pf, pituitary fossa; pla, planum antorbitale; pm, pila metoptica; pmp, posterior maxillary process; ppl, posterior process of planum antorbitale; pro, prootic; ps, planum supraseptale; psc, paraseptal cartilage; ptc, parietotectal cartilage; q, quadrate; rp, rostral process; rpp, rostral process of planum antorbitale; sc, sphenethmoid commisure; si, subiculum infundibuli; slps, secondary lateral process of paraseptal cartilage; so, supraoccipital; t, trabecula; tc, trabecula communis; te, tectum; tm, taenia medialis; tma, taenia marginalis; tp, trabecular process of acrochordal cartilage. Scale bar: 0.5 mm.