amphioxidae

NOUN
11 LETTERS · STARTS WITH A

amphioxidae is a valid 11-letter word worth 26 points in Scrabble and 27 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
A1M3P3H4I1O1X8I1D2A1E1
1 + 3 + 3 + 4 + 1 + 1 + 8 + 1 + 2 + 1 + 1 =26 PTS
DOUBLE WORD → 52TRIPLE WORD → 78
MEANING

What does amphioxidae mean?