Cartilaginous fish, such as sharks and rays also lack a true maxilla.
en.wikipedia.org Patients are usually born with underdeveloped mandible and maxilla that result in a distorted jaw and eyelids.
en.wikipedia.org The irregular bones are: the vertebr, sacrum, coccyx, temporal, sphenoid, ethmoid, zygomatic, maxilla, mandible, palatine, inferior nasal concha, and hyoid.
en.wikipedia.org For example, two teeth exposed on the occlusal plane of the rostral third and the posterior third of the dentary and maxilla, respectively.
en.wikipedia.org The longest teeth were in the maxilla (upper jaw bone), with crowns up to 85 millimeters (3.3 in) long.
en.wikipedia.org