Ischium the Latin term derives from Greek ἰσχίον "iskhion" meaning "hip joint". The division of the "acetabulum" into "ischium" (ἰσχίον) and "ilium" (λαγών, "os lagonicum") is due to Galen, "De ossibus". Galen, however, omits mention of the "pubis" as a separate bone. The clade Dinosauria is divided into the Saurischia and Ornithischia based on hip structure, including importantly that of the ischium. In the majority of dinosaurs, the ischium extends down from the ilium and towards the tail of the animal. The acetabulum, which can be thought of as a "hip-socket", is a cup-shaped opening on each side of the pelvic
Perpendicular plate of palatine bone Perpendicular plate of palatine bone The perpendicular plate of palatine bone is the vertical part of the palatine bone, and is thin, of an oblong form, and presents two surfaces and four borders. The nasal surface exhibits at its lower part a broad, shallow depression, which forms part of the inferior meatus of the nose. Immediately above this is a well-marked horizontal ridge, the conchal crest, for articulation with the inferior nasal concha; still higher is a second broad, shallow depression, which forms part of the middle meatus, and is limited above by a horizontal crest less prominent than the