|Basic info||Taxonomic history||Classification||Relationships|
|Morphology||Ecology and taphonomy||External Literature Search||Age range and collections|
If no rank is listed, the taxon is considered an unranked clade in modern classifications. Ranks may be repeated or presented in the wrong order because authors working on different parts of the classification may disagree about how to rank taxa.
|E. Hitchcock 1848||Heel elongated, apparently extending to the tarsal joint, quite narrow, making an impression as deep as the toes with its anterior part. Fourth toe procee ding at right angles from the heel behind the roots of the toes, resembling the spur on some of the gallinaceous birds.|