The word Pleiosurus is misspelled against Pleiosaurus, a noun meaning "Same as Pliosaurus."
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Word contains consecutive vowels 'AU' in between alphabets pleios & rus is misspelled as 'U' as letter 'A' is phonetically igno
Wrong Spelling:  pleios-u-rus 
Correct Spelling:  pleios-au-rus 
Check more misspelled words of Pleiosaurus to spell it correct.