Possible answers:
+ Echinoids;
+ Conifers;
+ deuterostomes;
+ bullfrogs;
+ frozen fossils;
+ one celled organisms;
+ Nematoda;
+ important habitats;

Fact 1: If fossils of an animal or plant are found in a place then that animal or plant used to live in that place. Fact 2: Frozen fossil animals are found in permafrost. Given the two facts above, if what are found in permafrost, that plant used to live in that place?
Answer:
frozen fossils