from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Either of two bones located in front of and between the maxillary bones in the upper jaw of vertebrates.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Either of a pair of bones in front of the maxillary bones in the upper vertebrate jaw
from the GNU version of the Collaborative International Dictionary of English
- n. A bone on either side of the middle line between the nose and mouth, forming the anterior part of each half of the upper jawbone; the intermaxilla. In man the premaxillæ become united and form the incisor part of the maxillary bone.
from The Century Dictionary and Cyclopedia
- n. The intermaxillary or premaxillary bone. See intermaxillary.
Sorry, no etymologies found.
The euenantiornithean Eoenantiornis has four subconical teeth in each premaxilla while there were probably six or seven teeth in each dentary, the rostral-most two of which were larger than the others (Zhou et al. 2005).
In Caudipteryx, four procumbent teeth are present in each premaxilla, but the rest of the skull is edentulous.
Incisivosaurus – closely related to, and possibly congeneric with, Protarchaeopteryx – has a reduced compliment of teeth, all of which are restricted to the anterior parts of the jaws, and two enlarged, bunny-like incisiform teeth project from each premaxilla (image at top: widely available on the web).
Although cranial fragments and mandibles were very abundant at the butchery place of the Odeon, the nasal bone and the most anterior part of the upper and lower jaw (premaxilla and mandible) were missing.
The occipital, the parietal, and frontal, the bones which surround the internal ear, the vomer, the premaxilla, and the quadrate bones, may be given as examples.
Mall40 and Fawcett41 maintain that it is ossified from two centers only, one for the maxilla proper and one for the premaxilla.
The small part in front of this suture constitutes the premaxilla (os incisivum), which in most vertebrates forms an independent bone; it includes the whole thickness of the alveolus, the corresponding part of the floor of the nose and the anterior nasal spine, and contains the sockets of the incisor teeth.
First comes the premaxilla (p.m.) (not p. m.1 or p. m.4), containing in the dog, the three incisors of either side.
The upper jaw has a great bar of cartilage, the palato-pterygoid, as its sole support; the arch of premaxilla, maxilla, jugal, and squamosal -- all membrane bones -- is, of course, not represented.
Poor preservation of the premaxillary margins mean that the number there can't be asserted with confidence either (though 4 teeth in each premaxilla is a good guess).