Source : Webster's Revised Unabridged Dictionary (1913)

Rhamphorhynchus \Rham`pho*rhyn"chus\, n. [NL., fr. Gr. "ra`mfos
   a beak + ???? snout.] (Paleon.)
   A genus of pterodactyls in which the elongated tail supported
   a leathery expansion at the tip.