The Early Eocene bird Gallinuloides wyomingensis - a stem group representative of Galliformes

We identified a second, perfectly preserved skeleton of the earliest known galliform bird, Gallinuloides wyomingensis Eastman. The new specimen clearly shows that G. wyomingensis does not belong to crown group Galliformes as assumed by earlier authors. In particular, the primitive presence of a deeply excavated, concave facies articularis scapularis at the coracoid precludes the inclusion of G. wyomingensis into crown group Galliformes. Gallinuloides wyomingensis is morphologically very similar to Paraortygoides messelensis Mayr, a nearly contemporaneous galliform from Messel, Germany. The exclusive presence of stem group galliform birds in pre−Oligocene deposits does not support the Gondwanan origin of Galliformes as evidenced by the Southern Hemisphere distribution of basal crown group members (Megapodiidae and Cracidae).