TABLE 1. Data source of 35 species of Czekanowskiales.
| No. | Species Name | References |
| 1 | Czekanowskia chinensis | Sun et al., 2009 |
| 2 | Czekanowskia shiguaiensis | Liu, 2016 |
| 3 | Czekanowskia elegans | Li et al., 1988 |
| 4 | Czekanowskia pumlia | Li et al., 1988 |
| 5 | Czekanowskia nathorsti | Wu, 1999 |
| 6 | Czekanowskia speciosa | Li et al., 1988 |
| 7 | Czekanowskia stenophylla | Li et al., 1988 |
| 8 | Czekanowskia explicita | Mi et al., 1996 |
| 9 | Czekanowskia hartzi | Wu et al., 1980 |
| 10 | Czekanowskia rigida | Miao, 2006 |
| 11 | Czekanowskia setacea | Mi et al., 1996 |
| 12 | Czekanowskia shenmuensis | Qian et al., 1987 |
| 13 | Phoenicopsis angustifolia | Li, 2018 |
| 14 | Phoenicopsis speciosa | Qian et al., 1987 |
| 15 | Phoenicopsis xiwanensis | Zhou, 1984 |
| 16 | Phoenicopsis ordosensis | Li et al., 2014 |
| 17 | Phoenicopsis huolinheiana | Sun et al., 1987 |
| 18 | Phoenicopsis jus'huaensis | Sun et al., 1987 |
| 19 | Phoenicopsis uralensis | Huang, 2016 |
| 20 | Phoenicopsis daohugouensis | Huang et al., 2016 |
| 21 | Phoenicopsis jilinensis | Sun et al., 1987 |
| 22 | Phoenicopsis decorata | Li et al., 1988 |
| 23 | Phoenicopsis enissejensis | Wang, 1995 |
| 24 | Phoenicopsis mira | Li et al., 1988 |
| 25 | Phoenicopsis neimengensis | Wang et al., 2014 |
| 26 | Sphenarion parvum | Chen et al., 1988 |
| 27 | Sphenarion latifolia | Chen et al., 1984 |
| 28 | Sphenarion lineare | Wang, 1984 |
| 29 | Sphenarion dicrae | Li et al., 1988 |
| 30 | Sphenarion angusitae | Huang et al., 2017 |
| 31 | Solenites murrayana | Yan and Sun, 2004 |
| 32 | Solenites haojiagouensis | Yang et al., 2018 |
| 33 | Solenites orientalis | Sun et al., 2001 |
| 34 | Solenites baishanensis | Li et al., 2015 |
| 35 | Solenites gracilis | Li et al., 2015 |
TABLE 2. Traits of Czekanowskiales and their types. MAC = Macro traits, Cuticular = Cuticular traits, Q = Quantitative traits, M = Qualitative traits.
| No. | Traits | Type |
| 0 | Leaf cluster length (or lobe length) (mm) | MAC; Q |
| 1 | Leaf cluster width (mm) | MAC; Q |
| 2 | Leaf cluster aspect ratio | MAC; Q |
| 3 | Lobe width (mm) | MAC; Q |
| 4 | Lobe aspect ratio | MAC; Q |
| 5 | The number of lobes | MAC; Q |
| 6 | The number of dichotomies | MAC; Q |
| 7 | Angle between the most lateral lobes (°) | MAC; Q |
| 8 | The number of veins | MAC; Q |
| 9 | Lobe shape: Linear, Thin linear, Narrow wedge, Wide wedge, Narrow band | MAC; M |
| 10 | Shape of lobe apex: Cuspate, Blunt tip, Round, Blunt round, Truncate | MAC; M |
| 11 | Leaf veins types: Unapparent, Parallel venation | MAC; M |
| 12 | Short shoot: Scaly, Scaly bud | MAC; M |
| 13 | Arrangement of upper epidermal cells: Linear, Irregular | Cuticular; M |
| 14 | Shape of upper epidermal cells: Long rectangle, Polygonal, Elongated | Cuticular; M |
| 15 | Surface ornamentation of upper epidermal cells: Striped, Ridged stripes, Papillate, Partial thickening, None | Cuticular; M |
| 16 | Anticlinal wall of upper epidermis cells: Straight, Straight and slightly curved | Cuticular; M |
| 17 | Area of upper epidermal cells (μm2) | Cuticular; Q |
| 18 | Aspect ratio of upper epidermal cells | Cuticular; Q |
| 19 | Arrangement of lower epidermal cells: Linear, Irregular | Cuticular; M |
| 20 | Shape of lower epidermal cells: Long rectangle, Polygonal, Elongated | Cuticular; M |
| 21 | Surface ornamentation of lower epidermal cells: Striped, Ridged stripes, Papillate, Partial thickening, None | Cuticular; M |
| 22 | Anticlinal wall of lower epidermis cells: Straight, Straight and slightly curved | Cuticular; M |
| 23 | Area of lower epidermal cells (μm2) | Cuticular; Q |
| 24 | Aspect ratio of lower epidermal cells | Cuticular; Q |
| 25 | Leaf stomatal type: Double-sided stomatal, Lower stomatal | Cuticular; M |
| 26 | Arrangement of stomatal apparatus: Linear, Irregular | Cuticular; M |
| 27 | Shape of the stomatal apparatus: Oval, Round, Long hexagon | Cuticular; M |
| 28 | Area of stomatal complex (μm2) | Cuticular; Q |
| 29 | Aspect ratio of the stomatal complex | Cuticular; Q |
| 30 | The number of subsidiary cells | Cuticular; Q |
| 31 | Surface ornamentation of subsidiary cells: Papillate, Thickening, None | Cuticular; M |
TABLE 3. Schematic table of label encoding and one-hot encoding.
| Trait Variables | Label Encoding | One-hot Encoding | ||
| A | B | C | ||
| A | 0 | 1 | 0 | 0 |
| B | 1 | 0 | 1 | 0 |
| C | 2 | 0 | 0 | 1 |
