The quadratojugal is a small jaw bone that is present in most amphibians, reptiles, and birds, but has been lost in mammals. It is connected to the jugal as well as other bones, though these may vary with species. The quadratojugal bone is a small bone between the cheek and otic notch (Lecointre 380). Squamates (lizards and snakes) lack a quadratojugal bone (Schwenk 193). [ http://en.wikipedia.org/wiki/Quadratojugal_bone ]
Synonyms: quadratojugal
Term information
- Wikipedia:Quadratojugal_bone
- AAO:0000532
http://upload.wikimedia.org/wikipedia/commons/e/eb/Skull_synapsida_1.png
https://upload.wikimedia.org/wikipedia/commons/6/6e/Archaeopteryx_skull.png
Paired intramembranous bones that completes the maxillary arch posteriorly; they appear at the end of, or just after, metamorphosis[AAO:0000532].
quadratojugale
quadrato-jugals
tympano maleaux
quadrato-maxillare
quadratjochbeine
http://purl.obolibrary.org/obo/NCBITaxon_8509
http://purl.obolibrary.org/obo/NCBITaxon_40674
Term relations
- bone of upper jaw
- dermal bone
- intramembranous bone
- in taxon some (not Mammalia)
- part of some skeleton of upper jaw
- in taxon some (not Squamata)
- part of some dermatocranium