Qiliania, GRAFFINI, 2011

Ji, Shu-An, Atterholt, Jessie, O, Jingmai K., Connor, Lamanna, Matthew C., Harris, Jerald D., Li, Da-Qing, You, Hai-Lu & Dodson, Peter, 2011, A new, three-dimensionally preserved enantiornithine bird (Aves: Ornithothoraces) from Gansu Province, north-western China, Zoological Journal of the Linnean Society 162 (1), pp. 201-219 : 215

PALAEOECOLOGY OF QILIANIA

Several recent studies (e.g. Hopson, 2001; Glen & Bennett, 2007) have used ecomorphological data from modern birds to propose methods for generating palaeoecological inferences for extinct avians based on the morphologies of these taxa as preserved in their fossils. One such method ( Hopson, 2001) involves the use of non-ungual pedal phalangeal proportions, in which specific patterns of non-ungual phalangeal proximodistal length are hypothesized to be indicative of particular lifestyles (e.g. an avian pes in which the non-ungual phalanges progressively increase in length distally is proposed to be indicative of perching). Qiliania , however, exhibits no clear trends in non-ungual phalangeal length; therefore, robust inferences cannot be made regarding the habits of this enantiornithine based on the morphology of its non-ungual phalanges alone.

Avian pedal ungual morphology, especially the curvature of such unguals [e.g. the ‘claw angle’ of Glen & Bennett (2007)], has also been used as a proxy for palaeoecology. Following the methods of Glen & Bennett (2007), we measured the ‘claw angle’ of the third pedal ungual of Qiliania at approximately 95°. The Changma taxon therefore resides, although somewhat ambiguously, within the groups that Glen & Bennett (2007) designated as ‘predominantly ground foragers’ and ‘predominantly arboreal foragers ’ niches that today are dominated by Columbiformes (doves and pigeons) and Cuculiformes (cuckoos and allies). Qiliania was therefore perhaps an Early Cretaceous analogue of these extant ecological generalists.

Interestingly, however, Dyke & Nudds (2008) noted that the pelvic limb proportions of many enantiornithine taxa differ significantly from those of extant avians. It is therefore reasonable to expect that the pedal morphology of at least some enantiornithines might fall outside of the range exhibited by modern birds as well. If so, and if Qiliania was one such taxon, then this might explain the difficulty we have encountered in attempting to reconstruct the palaeoecology of this form using the proportions of its nonungual pedal phalanges, as well as our inability to easily ‘shoehorn’ the taxon into one of the proposed ecological categories of Glen & Bennett (2007) based on the curvature of its pedal unguals. In conclusion, we follow Dyke & Nudds (2008) in considering the possibility that the morphologies and palaeoecologies of Qiliania , and at least some other enantiornithines, may not be directly comparable to those of modern birds.