Plesiosouria or Plesiosauria: How To spell?
The word Plesiosouria is misspelled against Plesiosauria, a noun meaning "An extinct order of Mesozoic marine reptiles including the genera Plesiosaurus, and allied forms; -- called also Sauropterygia."
Word contains consecutive vowels 'AU' in between alphabets plesios & ria is misspelled as 'OU'Wrong Spelling:  plesios-ou-ria  Correct Spelling:  plesios-au-ria 
Check more misspelled words of Plesiosauria to spell it correct.