Table 1. Reference of relevant fossil records and calibrations used in this study.
| Taxa | Node | Period | Calibration (Myr) | Reference |
| Arcellinida | A | Neoproterozoic, Cryogenian | ca. 662 | [35] |
| Arcellinida | A | Neoproterozoic | <770-742 | [15] |
| Centropyxis | B | Carnian (Triassic) | >220 | [37] |
| Hyalospheniidae | C | Albian– Cenomanian (Cretaceous) | >100 | [38] |
| Arcella | D | Mid Cretaceous | >100 | [36] |
| Difflugia | E | Lower Albian (Cretaceous) | >100 | [40] |
| Lesquereusia, Difflugia | E | Late Albian (Cretaceous) | >100 | [39] |
| Arcella, Centropyxis Difflugia, Lesquereusia | B, D, E | Early Permian | >299 | [49] |
| Arcella, Centropyxis Difflugia | B, D, E | Late Carboniferous–Early Permian | >299 | [42] |
Taxonomic assignment, geological time and period are taken from the references (right column). Placement of the fossil in each corresponding node (see Figure 2) is indicated. Time of the fossil record is in Myr (million years).