mesethmoid bone

mes·eth·moid bone

in comparative anatomy, the bone present in some species as the most anterior bone of the floor of the braincase.
References in periodicals archive ?
In the marabou stork, air flow passes into a mass of trabecular bone within the mesethmoid bones over a sheet of muscle attached to the left palatine bone cranial to the orbit and continues beneath the left eyeball, leaving the orbit by an opening in the orbital floor which gives direct access to the ventral air pouch (Fig 3).