protoctist family

NOUN
17 LETTERS · STARTS WITH P

protoctist family is a valid 17-letter word worth 28 points in Scrabble and 31 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
P3R1O1T1O1C3T1I1S1T1F4A1M3I1L1Y4
3 + 1 + 1 + 1 + 1 + 3 + 1 + 1 + 1 + 1 + 0 + 4 + 1 + 3 + 1 + 1 + 4 =28 PTS
DOUBLE WORD → 56TRIPLE WORD → 84
MEANING

What does protoctist family mean?