Table 1. Character state scores for patellar form in Palaeognathae, Neognathae and Hesperornithiformes, following the scores 0–4 described in the Methods.
Basal outgroups to these taxa (e.g., Apsaravis, Yixianornis, Yanornis, Enantiornithes, other extinct birds) lack a patella (Hou, 1997; Clarke & Norell, 2002; Clarke, Zhou & Zhang, 2006; Zhou, Clarke & Zhang, 2008; Wang et al., 2013). Scores for taxa above the genus level were gauged by comparisons of multiple taxa within that clade and the polarity of characters within it (using published phylogenies as cited in the main text), where variation existed.
| Taxon | Patellar form (character state) |
|---|---|
| Hesperornithiformes | Proximodistally elongate crest (4) |
| Neoaves | Small flake of bone (1) |
| Galloanserae | Rounded nodule (2) |
| Struthio (ostriches) | Large rectangular block with articular surfaces mediolaterally (3) |
| Rheiidae (rheas) | No data (?) |
| Tinamiformes (tinamous) | Small flake of bone (1) |
| Casuarius (cassowaries) | Absent (0) |
| Dromaius (emus) | Absent (0) |
| Dinornithiformes (moas) | Absent (0) |
| Apteryx (kiwis) | Small flake of bone (1) |
| Aepyornithiformes (elephant birds) | No data (?) |