| Songzia heidangkouensis|
| Songziidae (but see text)
LianHai Hou, 1990|
Eogruidae, Gruiformes, Ludiortyx, Idiornithidae, Zhongyuanus
LianHai Hou. 1990. An Eocene bird from Songzi, Hubei province. Vertebrata PalAsiatica 28(1):34-42
Min Wang, Gerald Mayr, Jiangyong Zhang & Zhonghe Zhou, 2012. Two New Skeletons of the Enigmatic, Rail-like Avian Taxon Songzia Hou, 1990 (Songziidae) from the Early Eocene of China. Alcheringa 36: 487-499
Songzia is a genus of gruiform bird related to rails. It lived in the Eocene epoch. Though many families traditionally assigned to the Gruiformes do not seem to actually belong there, this is apparently not the case with this animal. Its fossils have been found in Songzi county (Hubei Province People's Republic of China).
Two species are known and have been named Songzia heidangkouensis and Songzia acutunguis. However, the names for the first species, genus and family have been first published in a newsletter and only subsequently in a scientific journal that fulfils the ICZN's requirements for publishing new scientific names. Hence, they are often considered nomina nuda, after it was published in a scientific journal it was valid.