Via Science News:  …. The team’s microRNA sequencing results also agree with the order in
which the different annelids and their relatives appear in the fossil
record—something that previous hypotheses about their relationships had
failed to do, said co-author Derek Briggs, Yale’s Frederick William
Beinecke Professor of Geology and Geophysics.

“This study is an elegant example of how new methods can reconcile
results from molecular sequencing of living animals with information
from the fossil record,” he said…