Plesiosurian or Plesiosaurian: How To spell?
The word Plesiosurian is misspelled against Plesiosaurian, a noun meaning "A plesiosaur."
Word contains consecutive vowels 'AU' in between alphabets plesios & rian is misspelled as 'U' as letter 'A' is phonetically igWrong Spelling:  plesios-u-rian  Correct Spelling:  plesios-au-rian 
Check more misspelled words of Plesiosaurian to spell it correct.