15-Letter Words Containing: A,C,E,E,R,R,S

• extinct primitive toothed bird of the Jurassic period having a long feathered tail and hollow bones; usually considered the most primitive of all birds

• A device that uses diffraction (especially X-ray diffraction) to investigate the structure of matter.

• the area of mesoderm that forms the notochord

• a graphical record of electric currents associated with muscle contractions