The Collaborative International Dictionary of English v.0.48:

Meckelian \Meck*e"li*an\, a. (Anat.)
   Pertaining to, or discovered by, J. F. Meckel, a German
   anatomist.
   [1913 Webster]

   Meckelian cartilage, the cartilaginous rod which forms the
      axis of the mandible; -- called also Meckel's cartilage.
      [1913 Webster]