Which groups did the initial analysis by Xu et al. suggest Xiaotingia grouped closely with, excluding traditional birds?
Answer
Archaeopteryx, Dromaeosauridae, and Troodontidae
The initial phylogenetic analysis conducted by Xu and colleagues when introducing *Xiaotingia* in 2011 resulted in a grouping that significantly challenged prior assumptions about avian evolution. Their findings placed *Xiaotingia* in close association with *Archaeopteryx*, as well as the Dromaeosauridae and the Troodontidae families. Crucially, this specific grouping explicitly excluded other dinosaurian groups that had sometimes been classified traditionally as birds under different phylogenetic definitions, leading to widespread popular reports questioning the status of *Archaeopteryx* itself under their defined parameters.
Related Questions
Roughly when did Xiaotingia zhengi exist based on Bathonian and Oxfordian stages?What was the estimated total length of the diminutive Xiaotingia?Which anatomical marker suggests Xiaotingia sat closer to the Deinonychosaurs branch?For which paleontologist was the specific epithet zhengi of Xiaotingia zhengi an honorific?What is the designation for the almost complete type specimen of Xiaotingia that includes the skull?How is the diet of Xiaotingia zhengi categorized by paleontologists?Besides the head and body, where else was Xiaotingia clearly covered in feathers?What capability might be suggested by the femur (84 mm) being longer than the humerus (71 mm) in Xiaotingia?Which groups did the initial analysis by Xu et al. suggest Xiaotingia grouped closely with, excluding traditional birds?From which geological formation in China was the specimen of Xiaotingia likely recovered?