Cathayornis

Cathayornis
Temporal range: Early Cretaceous, 120 Ma
↓
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Subclass: †Enantiornithes
Superorder: †Euenantiornithes
Order: †Cathayornithiformes
Family: †Cathayornithidae
Genus: †Cathayornis
Zhou, Jin & Zhang, 1992
Type species
†Cathayornis yandica
Zhou et al., 1992
Species
  • †C. yandica Zhou et al., 1992
  • †C. caudatus? Hou, 1997
  • †C. aberransis? Hou et al., 2002
  • †"C." chabuensis Li et al., 2008

Cathayornis is a genus of enantiornithine bird from the Jiufotang Formation of Liaoning, People's Republic of China and, in the case of the possible species C. chabuensis, from the Jingchuan Formation of Inner Mongolia.

Contents

Description and species

Zhou and Hou (2001) distinguished Cathayornis from the similar Sinornis by the former's larger size, a shorter, straighter, finger number I, with a slightly longer claw (ungual), the absence of an atitrochanter, and other features. The type and possibly only species is Cathayornis yandica.[1]

Other species – C. aberransis,[2] C. chabuensis[3] and C. caudatus[4] – have been described. However, their validity and/or assignment to the genus Cathayornis has been questioned in subsequent evaluations. Jingmai O'Connor and Gareth Dyke (2010) found that many of the supposedly distinct features of C. aberransis (such as the base of a crest on the skull) had been inaccurately described, casting doubt on the few remaining features separating it from C. yandica, and suggested that further study was needed to determine its validity.[5] Similarly, C. caudatus was so named for its supposedly bony tail lacking a pygostyle, and was further differentiated by its small size. O'Connor and Dyke re-examined the specimen and showed that the specimen is in fact only slightly smaller than the type specimen of C. yandica, and that a normal enantiornithine tail with a pygostyle is clearly visible in one of the fossil slabs, parts of the hip bones having been mistaken for unfused tail vertebrae. O'Connor and Dyke therefore considered C. caudatus a nomen dubium.[5] On the other hand, C. chabuenis is clearly distinct from C. yandica and cannot be assigned to the cathayornithiformes, so it most likely represents a new genus.[5]

Classification

Paul Sereno et al., in 2002, considered Cathayornis a junior synonym of Sinornis. They interpreted the anatomies of the two as very similar and sharing key autapomorphies of the pygostyle.[6]

The first thorough review of Sinornis and Cathayornis was published by Jingmai O'Connor and Gareth Dyke in 2010. O'Connor and Dyke concluded that despite the earlier opinion of Sereno and colleagues, the two birds were not synonyms and in fact differ in several clear ways, including different proportions in the wing claws and digits, differences in the pelvis, and size of the pygostyle.[5]

References

  1. ^ Zhou, Zhonghe, Hou and Lianhai. (2001). "The Discovery and Study of Mesozoic Birds in China." In Chiappe, L. and Witmer, L. (eds.), Mesozoic Birds: Above the Heads of Dinosaurs. 2001: University of California Press.
  2. ^ Hou, Zhou, Zhang and Gu, (2002). Mesozoic birds from western Liaoning in China. ISBN 7-5381-3392-5. 120 pp.
  3. ^ Li, J., Li, Z., Zhang, Y., Zhou, Z., Bai, Z., Zhang, L. and Ba, T. (2008). "A new species of Cathayornis from the Lower Cretaceous of Inner Mongolia, China and its stratigraphic significance." Acta Geologica Sinica, 82(6): 1115-1123.
  4. ^ Hou, 1997. Mesozoic Birds of China. Phoenix Valley Bird Park, Lugu Hsiang, Taiwan. 221 pp.
  5. ^ a b c d O'Connor, J. and Dyke, G. (2010). "A reassessment of Sinornis santensis and Cathayornis yandica (Aves: Enantiornithes)." Records of the Australian Museum, 62: 7-20. doi:10.3853/J.0067-1975.62.2010.1540
  6. ^ Sereno, Rao and Li, (2002). "Sinornis santensis (Aves: Enantiornithes) from the Early Cretaceous of Northeastern China." Pp 184-208. in Chiappe and Witmer (eds.), Mesozoic Birds – Above the Heads of Dinosaurs. Berkeley: University of California Press

External links