1: the same or 25% greater than the length of the femur
2: more than 25% the length of the femur
Modified: a new state 1 was added because some taxa, e.g., Yanornis martini, have a skull longer than the femur but less than 25% of the length of this bone.
Character 855: Postantral wall of the maxilla posteriorly extended (Novas et al., 2009)
Character 856:Striations on the crowns of the teeth (Gianechini et al., 2011)
Striations on the crowns are considered as two or more longitudinal furrows on the labial and/or lingual surface. Isolated furrows, as those observed in Sinornithosaurus millenii, are not considered as striations.
Character 883: A pair of extremely elongated pennaceous feathers (e.g. PRPFs)
Character 884: Egg geometry
2: asymmetric with modern avian outline
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