part of part of in taxon Mammalia Squamata intramembranous bone dermatocranium skeleton of upper jaw dermal bone quadratojugal bone http://upload.wikimedia.org/wikipedia/commons/e/eb/Skull_synapsida_1.png https://upload.wikimedia.org/wikipedia/commons/6/6e/Archaeopteryx_skull.png UBERON:0011267 Paired intramembranous bones that completes the maxillary arch posteriorly; they appear at the end of, or just after, metamorphosis[AAO:0000532]. quadratojugal quadrato-jugals tympano maleaux 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). quadratojugale quadrato-maxillare Wikipedia:Quadratojugal_bone quadratjochbeine AAO:0000532 bone of upper jaw