Cleithrum

The Cleithrum ( altgr. κλειθρον small thrombogenic, lock, bolt ') is a paired bone in the shoulder girdle cover not amniotic amniotic and primitive vertebrates. A Cleithrum have all bony fishes, on the other hand it lacks the cartilaginous fish. In primitive bony fish, such as sturgeon species, the gars and the bowfin it is on the scapula, the outside of the body. As the only extant land vertebrates the frogs still have a Cleithrumrest which lies at the anterior border of the cartilaginous Suprascapula. All extant amniotes ( reptiles, birds, mammals ) are without Cleithrum.

Swell

• Dictionary of Biology. Volume 2 page 286 publisher Herder, Freiburg im Breisgau, 1985, ISBN 3-451-19644-1
• Cleithrum in Fishbase - Glossary

• Bones of upper limb