Fig. 2. Incomplete skull of the acanthothoracid placoderm Palaeacanthaspis vasta Brotzen, 1934 (ZPAL Ag. V/1) from the middle Lochkovian of Vynohradne, Podolia, Ukraine, in ventral (A1), left (A3) and right (A2) lateral, dorsal (A4), and anterior (A5) views. Abbreviations: a.pop, anterior postorbital process; a.pr.br, articular facet for the dorsal elements of the branchial basket; av.myo, anteroventral myodome; c.VI, canal for the abducens nerve; c.VII, canal for the (main trunk of the) facial nerve; c.VIII, canal for the acoustic nerve; c.IX, canal for the glossopharyngeal nerve; c.pit.v, canal for the pituitary vein; c.X, canal for the vagus nerve; cc.a.g, common carotid artery groove; d.end.e, external opening for the endolymphatic duct; d.myo, dorsal myodome; e.c, cranial cavity; e.s, eyestalk; ehy+op.art, articular facet for the epihyal and opercular cartilages; f.III.1–2, foramina for the oculomotor nerves; f.IV, foramen for the trochlear nerve; f.V.1, foramen for the first branch of the trigeminal nerve; f.V.2–3, foramen for the second and third branches of the trigeminal nerve; f.VI, foramen for the abducens nerve; f.VII.hm, foramen for the hyomandibular branch of the facial nerve; f.X, foramen for the vagus nerve; f.ic.a, foramen for the internal carotid artery; f.j.v, foramen for the jugular vein; f.pit.v, foramen for the pituitary vein; g.II, groove for the optic nerve; g.V.2–3, groove for the second and third branches of the trigeminal nerve; g.ac.v, groove for the anterior cerebral vein; g.eff.a, groove for the efferent artery; g.ehy.a, groove for the epihyal artery; g.ic.a, groove for the internal carotid artery; g.op.a, groove for the opercular artery; g.rn.cap, groove for the insertion of the ventral part of the rostronasal capsule; ins.rn.cap, insertion slit for the dorsolateral portion of the rostronasal caspule; ioc, infraorbital sensory line groove; lc, cephalic part of the main lateral sensory line groove; mpt.art, articulation facet for the metapterygoid; occ, occipital cross commissure; pmc, postmarginal sensory line groove; p.pop, posterior postorbital process; pfc, profundus sensory line groove; pmc, postmarginal sensory line groove; ppl, posterior pitline; pv.myo, posteroventral myodome; sac, saccula of the inner ear; soc, supraorbital sensory line groove; v.myo, ventral myodome; VII.pal.c, canal for the palatine ramus of the facial nerve.