ornithischian

NOUN /,ɔrnə'θɪskiən/
13 LETTERS · 5 SYLLABLES · STARTS WITH O

ornithischian is a valid 13-letter word worth 21 points in Scrabble and 22 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
O1R1N1I1T1H4I1S1C3H4I1A1N1
1 + 1 + 1 + 1 + 1 + 4 + 1 + 1 + 3 + 4 + 1 + 1 + 1 =21 PTS
DOUBLE WORD → 42TRIPLE WORD → 63
MEANING

What does ornithischian mean?