These animals relied on each other for 100 million years. Now climate change is killing them both.

Hoyal Cuthill...is the lead author of a study...on the long — and probably doomed — relationship between Australia's 37 species of spiny mountain crayfish (members of the genus Euastacus) and their 33 species of flatworm symbionts (called temnocephalans).

As the continent warms, crayfish need to migrate to higher and higher altitudes to escape the high temperatures. But, as Hoyal Cuthill pointed out, at some point mountains have peaks. Trapped between the sky and the rising heat, endangered euastaceans — 75 percent of the entire genus — will likely perish. With no place for them to live, the flatworms will quickly follow