Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Evolutionary timescale for the Ephemeroptera inferred from the PCGs dataset based on phylogenetic analyses using four fossil calibration points. Each fossil calibration point is marked with a black dot on the figure. Median ages on the chronogram are provided above nodes. A geological time scale is shown at the bottom.
