"Globally, the Early Triassic benthic ecosystem functioned much like a ship manned by a skeleton crew. Each post was occupied, but by only a few individual taxa (groups)," Foster said.
That skeleton crew appeared to be enough, however, to keep intact the lifestyles that have defined benthic animals ever since.
To come to that conclusion, Foster and Twichett had the daunting task of sorting through the worldwide benthic fossil record from that pivotal time in Earth's history.
Previous studies have looked at the groups that went extinct, of course, as well as how new lifestyles "went viral" and spread through the world, but this is the first to look at the greatest extinction solely terms of animal roles -- or the "ecospace" -- that animals filled.
"We sort of ignored (the animals') names for this study," explained Foster. One advantage of this approach, he said, is that when the fossil record lacks evidence of a particular animal for a period of time, you can sometimes follow the lifestyle to fill in the blanks.