placoderm

1.pineal foramen A small opening in the skull roof in the pineal plate of Placoderms and Agnatha and between the frontals in Osteichthyes - the "third eye".

松果孔盔甲鱼和无颌鱼头盖骨顶部松果板内开口；硬骨鱼额骨开口-「第三个眼」。