Which grouping did the initial 2011 analysis controversially position *Xiaotingia* and *Anchiornis* within?
Answer
Archaeopterygidae
The initial phylogenetic analysis conducted in 2011 regarding *Xiaotingia* proposed a classification that had significant implications for the definition of Aves (birds). This analysis placed both *Xiaotingia* and *Anchiornis* within the family Archaeopterygidae. This placement led to a controversial suggestion at the time: if a strict definition of Aves was enforced, *Archaeopteryx* itself might subsequently be excluded from the bird group. This uncertainty stems from *Xiaotingia*'s mosaic anatomy, possessing traits shared by both birds and their non-avian dinosaurian cousins.
Related Questions
What is the holotype specimen ID for *Xiaotingia* found in the Tiaojishan Formation?Who was the genus name *Xiaotingia* chosen to honor regarding the holotype specimen?During which geologic interval did *Xiaotingia* live, estimated around 165 to 153 million years ago?What modern bird is *Xiaotingia*'s estimated size comparable to, given its small stature?What specific type of feather impressions were noted on the tibia and metatarsus of *Xiaotingia*?How did the femur length compare to the humerus length in *Xiaotingia*'s potentially flight-related arm structure?Which superorder assignment consistently includes *Xiaotingia* within the hierarchy leading to birds?Which grouping did the initial 2011 analysis controversially position *Xiaotingia* and *Anchiornis* within?Which clade did Senter et al. (2012) suggest *Xiaotingia* was the most primitive member of in a revised analysis?What evolutionary concept describes the acquisition of bird traits independently across several closely related lineages like those in the Yanliao Biota?What cranial feature does *Xiaotingia*'s shallow snout align it morphologically closer to, rather than basal avialans like *Jeholornis*?