† notostomen.
Palaeontology. Obsolete. rare.
A dorsal opening on the midline of the skull in certain fossil armoured fishes (erroneously supposed to represent an ancestral mouth); the pineal foramen.The fossils discussed in the quots. are now identified as placoderms.
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notostome1885
1885 E. D. Cope in Amer. Naturalist 19 290 The anterior orifice is surrounded by six scuta... But they are differently arranged in the Pterichthyidae, one forming a median valve of the mouth or notostome [printed notosome].
1887 E. D. Cope Origin Fittest 323 The valve of the dorsal mouth, or notostome, is broken.
This entry has been updated (OED Third Edition, December 2003; most recently modified version published online December 2018).
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n.1885