Research 
Dissertation Project:
Enantiornithines, the ‘opposite birds,’ are a group of Mesozoic birds with a relatively short scientific history. Since the group was first recognized as the fourth known “subclass” of birds in the 1980’s (Walker 1981), more than 50 species have been named, and specimens have been collected from every continent with the exception of Antarctica (Chiappe and Walker 2002). These primitive birds comprised a major component of Cretaceous avifaunas, coexisting with other groups of birds, both more primitive and advanced. These birds lived in a variety of environments ranging from lacustrine, desert, and near shore (Chiappe and Walker 2002). Enantiornithines occupy a considerable size range, from very small, sparrow-sized taxa to taxa the size of a turkey vulture (Chiappe and Walker 2002). The diversity of the group is reflected by the development of numerous diverse feeding and locomotor specializations (Hou et al. 2004). Enantiornithines are the first group of birds to undergo a large-scale radiation; despite their short history, they are more taxonomically diverse than any other group of birds in the Mesozoic. They dominated the avian component of most Cretaceous faunas making their subsequent extinction at the end of the Cretaceous perplexing. Researching these primitive birds has the potential to of contribute to our understanding of the larger picture of early avian evolution as a whole.
My research aims to better understand the evolutionary history and relationships of the Enantiornithes through:
- A systematic revision of the numerous fragmentary taxa
- Conducting a species level cladistic analysis of all known enantiornithines
- Interpreting the resulting phylogenetic hypotheses to better understand the evolutionary history of the group in terms of size, ecology, and acquisition of morphological traits
- Using new knowledge of molecular signals within Aves to correlate nodes within the cladogram with major developmental events
- Providing detailed and well illustrated descriptions drawings for poorly described or previously unknown taxa and specimens
- Creating comprehensive reviews of topics such as feather diversity, tail morphology, pneumaticity, and other morphological systems, as well as life history and habitat within Enantiornithes in search of possible correlations
This knowledge will be integrated into broader impact research issues such as studies regarding avian flight, the origin of birds, and the selectivity of the end-Cretaceous extinction, as well as help us better understand Mesozoic life and the conditions in which organisms survived, diversified, and in the case of Enantiornithes, radiated.
Current Projects
Wang, X-R, O'Connor, JK, DNHM et al. New enantiornithine from Liaoning. Yea, ANOTHER one.
O'Connor JK and Chiappe LM. Review of enantiornithine skull morphology.
Chiappe LM, O'Connor JK, DNHM et al. New hongshanornithid.
Zhang Y-G, Zhou Z-H and O'Connor JK. PCA of the tarsometatarsus of Mesozoic birds.