pleurostea

from The Collaborative International Dictionary of English v.0.48

Pleurosteon \Pleu*ros"te*on\, n.; pl. L. {Pleurostea}, E.
   {-ons}. [NL., fr. Gr. ? a rib + ? a bone.] (Anat.)
   The antero-lateral piece which articulates the sternum of
   birds.
   [1913 Webster]