Table 2. Divergence times from 5 proteins +SSU rDNA dataset under different calibration schemes.

	Root	Arcellinid core	Hyalospheniidae	Arcella-Hyalospheniidae
Four fossils (A, B, C, D)	483	341	132	273
	(334–703)	(245–486)	(100–198)	(220–386)
Five fossil (A, B, C, D), Difflugia (E) >100-<770	534	378	141	305
	(381–749)	(270–527)	(100–216)	(220–424)
Five fossil (A, B, C), Difflugia (E) >100<105 and Arcella (D) >100<770	568	400	145	326
	(408–766)	(286–571)	(100–228)	(229–459)
Four fossils (A, C, D) Centropyxis (B) >299 <770	573	409	146	332
	(440–757)	(324–529)	(100–225)	(299–417)

Divergence times for major clades are indicated in Myr (million years). Capital letters represent fossil calibrations (upper and lower bounds) for the corresponding node (see Figure 2): A) root <770 Myr, B) Centropyxis clade >220<770 Myr, C) Hyalospheniidae >100 <770 Myr, D) Arcella >100 <105 Myr, unless otherwise specified and E) corresponds to the node Difflugia-Lesquereusia.