crotalus horridus atricaudatus

NOUN
30 LETTERS · STARTS WITH C

crotalus horridus atricaudatus is a valid 30-letter word worth 37 points in Scrabble and 43 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
C3R1O1T1A1L1U1S1H4O1R1R1I1D2U1S1A1T1R1I1C3A1U1D2A1T1U1S1
3 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 0 + 4 + 1 + 1 + 1 + 1 + 2 + 1 + 1 + 0 + 1 + 1 + 1 + 1 + 3 + 1 + 1 + 2 + 1 + 1 + 1 + 1 =37 PTS
DOUBLE WORD → 74TRIPLE WORD → 111
MEANING

What does crotalus horridus atricaudatus mean?