Table 1.
Earliest reasonably confident fossil dates for the major eukaryote groups.
| taxa | date (Myr ago) | reference |
|---|---|---|
| unikonts | ||
| opisthokonts | ||
| Animalia | 550 | Conway Morris (2006) |
| Fungi | 460a | Padovan et al. (2005) |
| Choanozoa | no fossils | |
| Amoebozoa (Lobosea: Arcellinida) | 760 | Porter & Knoll (2000) |
| bikonts | ||
| Rhizaria | ||
| Retaria | ||
| Foraminifera | ||
| unilocular | 535 | McIlroy et al. (2001) |
| multilocular | 390 | Armstrong & Brasier (2005) |
| Radiozoa | 505 | Won & Below (1999) |
| Cercozoa | ||
| Euglyphida | 15 | Foissner & Schiller (2001) |
| Ebriida | 60–65 | Tappan (1980) |
| Phaeodaria | 75 | Takahashi (2004) |
| Excavata | no certain fossils; claims for euglenoids and kinetoplastids all post-Permian | |
| Plantae | ||
| Viridaeplantae | ||
| Chlorophyta | 540 | Tappan (1980) |
| Embryophyta | 475 | Wellman et al. (2003) |
| Rhodophyta | 570 | Xiao et al. (2004) |
| Glaucophyta | no fossils | |
| chromalveolates | ||
| Alveolata | ||
| Ciliophora | 100 | Acaso et al. (2005) |
| Myzozoa | ||
| Dinozoa | ||
| Peridinea | 240 | Fensome et al. (1993) |
| Chromista | ||
| Cryptista | no fossils | |
| Heterokonta | ||
| Ochrophyta | ||
| Silicoflagellata | 105–110 | McCartney (1993) |
| Chrysomonadea | 75 | Cornell (1972) |
| Diatomea | 185 | Tappan (1980) |
| Haptophyta | ||
| coccolithophorids | 225 | Bown et al. (2004) |
a
A claim for 600 Myr old ‘lichen-like’ fossils (Yuan et al. 2005) is doubly confusing. Lichens are large fungi that cultivate cyanobacteria within their tissues. These fossils are entirely different; cyanobacteria (less likely green algae) are permeated by filaments so slender that they are probably actinobacteria not fungi; analogy with actinobacterial endophytes of cereal plants is more apposite (Conn & Franco 2004; Tian et al. 2004).