Steller's __; Marine Mammal Extinct Since 1768

This page is the CodyCross answer for the clue below from Taking Care of Our Planet, Group 1568, Puzzle 4 (Reforestation).

Question is: Steller's __; Marine Mammal Extinct Since 1768

and the answer is: SEACOW

Word Meaning:

SEA COW — (zoology) Synonym of sirenian.

Definitions from Wiktionary.