Sapeornis and other Mesozoic Birds

[Ralph Miller <ralph.miller@alumni.usc.edu>]

A label in the exhibit, "Dinosaurs: Ancient Fossils, New Discoveries" (see
http://www.amnh.org/exhibitions/dinosaurs/diorama/specieslist.php), reads:

"Sapeornis chaoyangensis
largest-known Mesozoic bird"

I know that this is incorrect, as the flightless _Gargantuavis_ was about
the size of an ostrich. 

So is _Sapeornis_ the largest known FLYING Mesozoic bird?  
The largest known EARLY Mesozoic bird?  
The Mesozoic bird with the best press agent?  Or what? 

Ralph W. Miller III
Docent at the California Academy of Sciences
Dinosaur and Fossil Education
Member of the Society of Vertebrate Paleontology