Premaxillary

Some kind of premaxillary crest was present, but the skull is not well preserved enough to determine its original shape. ❋ Darren Naish (2006)

It seems that these birds lost the teeth from the back of the jaws first, and kept their premaxillary and dentary-tip teeth the longest. ❋ Darren Naish (2006)

In archaeopterygids for example, the premaxillary teeth are more peg-like and more procumbent than are the other teeth. ❋ Darren Naish (2006)

Having mentioned tyrannosauroids, I might also note that basal forms combine proportionally small premaxillary teeth with quill-like integumentary structures that would have needed preening (or is grooming the correct term here?). ❋ Darren Naish (2006)

It now seems that nearly all of the characters proposed initially to distinguish Tupuxuara from other pterodactyloid pterosaurs are problematic in not being unique to the genus, but in fact Tupuxuara is clearly diagnosable, being unique in having a sort of deep premaxillary crest in which the dorsal margin extends subparallel to the dorsal margin of the nasoantorbital fenestra (Martill & Naish 2006, p. 931). ❋ Darren Naish (2006)

Could those little premaxillary teeth have been specialized for ectoparasite control? ❋ Darren Naish (2006)

Basal tyrannosauroids and other basal coelurosaurs that possess specialised premaxillary teeth that might have been used in preening/grooming of quill-like integumentary structures. ❋ Darren Naish (2006)

In Protarchaeopteryx, teeth are restricted to the premaxillae and anterior parts of the maxillae and dentaries, with the premaxillary teeth being a few times taller than the others (Ji et al. 1998). ❋ Darren Naish (2006)

In Sinornithosaurus, a diastema separates the premaxillary teeth from the maxillary teeth, and the premaxillary teeth appear notably shorter than the maxillary ones (Xu & Wu 2001). ❋ Darren Naish (2006)

Pressure-sensitive organs termed Herbst corpuscles, embedded within pits on the premaxillary and dentary tips, are closely packed and particularly numerous in birds that probe sediments. ❋ Darren Naish (2006)

More derived oviraptorosaurs were toothless, but the bony premaxillary margins of their upper jaw were serrated, raising the possibility that the tomium was serrated too. ❋ Darren Naish (2006)

The score mark matches precisely the dimensions of a tyrannosaurid premaxillary tooth tip, as Luis is demonstrating with the help of a handy set of tyrannosaurid premaxillae he just happens to own. ❋ Darren Naish (2006)

Those short premaxillary teeth present in tyrannosauroids have conventionally been regarded as having a primary role in feeding, and it might be easy to confirm this by looking for micro - or macrowear. ❋ Darren Naish (2006)