Appendices of basal Anseriformes from the early Paleogene of North America and Europe

We describe nearly complete skeletons of basal Anseriformes from the
Latest Paleocene to the early Eocene of North America and Europe.
Collectively, these birds appear to be representative of anseriforms near
the divergence of Anhimae and Anseres, but their exact positions relative
to these clades remains uncertain. A new family, Anachronornithidae nov.
fam., is erected on the basis of one of these, Anachronornis anhimops nov.
gen., nov. gen. et sp., to which the others cannot be confidently
assigned. The new fossils augment a growing collection of early
Pan-Anseriformes, which in their diversity do not paint an unambiguous
picture of phylogeny or character state evolution on the path to or within
crown-Anseriformes. Anachronornis nov. gen. is similar in some aspects of
both cranial and postcranial anatomy to other well-represented early
Paleogene Anseriformes and members of Anseres, such as Presbyornis
Wetmore, 1926. However, it exhibits a more landfowl-like bill, like that
of Anhimae and unlike the spatulate bill of Anseres. Additional specimens
of similar basal Anseriformes of uncertain affinities from the early
Eocene of North America and Europe further complicate interpretation of
character state polarity due to the mosaicism of primitive and derived
characters they exhibit.