internal nares

…In the Paleozoic bony fishes known as the Lophophorus, the nose was not simply a depression, but had two openings on either side of the roof of the oral cavity, i.e., the palate. The openings on the outside were called the external nares, and the openings on the palate were called the internal nares. These, along with the presence of lungs, are thought to have made it possible for the fish to breathe air. In other words, the nose of the Lophophorus was the first nasal organ to serve as both an entrance to the olfactory and respiratory systems (however, the coelacanths, which are extant Lophophorus species, have lost the internal nares). …

*Some of the terminology that mentions "internal nares" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…古生代の高等硬骨魚であった総鰭（そうき）類では，鼻は単なるくぼみではなく，左右のそれぞれが口腔の天井，つまり口蓋の両わきに開通していた。外面に開いた穴を外鼻孔，口蓋に開いた穴を内鼻孔internal naresといい，肺があったことと並んで，これらが空気呼吸を可能にしていたと考えられる。つまり，総鰭類の鼻は嗅覚器と呼吸器の入口を兼ねる最初の鼻器であった(ただし，現存の総鰭類であるシーラカンス類には内鼻孔は失われている)。…

※「internal nares」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報