Figure 5

Developmental origins of the dermal skull roof. (A and B) Different views of the neural crest. Noden (1982, 1984) [80,81] placed the neural crest-mesodermal boudary in the dermal skull roof in the rostral part of the avian frontal (A), whereas Couly at al. (1993) [82] reported that the entire dermal skull roof is derived from the neural crest. Note that the occipital represents an endoskeletal vertebral element secondarily assimilated to the cranium in gnathostomes. (C) Developmental origins of the dermal skull roof and the posterior cranium in the mouse, based on transgenic approaches by [70,72,83,84]. Neural crest-mesoderm boundary is located at the boundary between the frontal and parietal. (D-G) Neural crest- and mesodermal origins of the cranial elements in zebrafish based on transgenic techniques by Kague et al. (2012) [73]. Names of the bones were revised based on comparative osteology by [85,86]. Dorsal view of the chondrocranium (D), and left lateral (E), dorsal (F), and ventral (G) views of adult zebrafish. In these views, the elements colored grey are of mesodermal origin. Note tha the neural crest-mesodermal boundary of the dermal skull roof is found in the frontal of this animal. Abbreviations: boc, basioccipital; bp, basal plate; cl, cleithrum; co, coracoid; d, dentary; e, ethmoid; eoc, exoccipital; fr, frontal; hm, hyomandibula; ia, intercalar; iop, interopercle; ip, interparietal; k, kinethomoid; le, lateral ethmoid; mpt, metapterygoid; mx, maxilla; nas, nasal; nc, notochord; oc, otic capsule; occ, occipital; op, opercle; os, orbitosphenoid; par, parietal; pe, preethmoid; pm, premaxilla; po, periotic; pop, preopercle; pp, postparietal; pro, prootic; ps, parasphenoid; pto, pterotic; pts, pterosphenoid; q, quadrate; se, supraethmoid; soc, supraoccipital; so, supraorbital; soc, supraoccipital; sop, subopercle; sph, sphenotic; sq, squamosal; st, supratemporal; tc, trabecula; tma, taenia marginalis anterior; tmp, taenia marginalis posterior; Redrawn from [8] (A-C) and from [73] (D-G).