Acheroraptor

Classification[edit]
The phylogenetic position of Acheroraptor was explored by Evans et al. (2013) using several data matrices. Both specimens of Acheroraptor were coded as a single taxon into Turner et al. (2012) data matrix, an extensive phylogenetic analysis of theropods that focuses on maniraptorans. Acheroraptor was recovered as a member of the clade containing Eudromaeosauria and Microraptorinae, confirming its referral to the Dromaeosauridae, and possibly to Eudromaeosauria. Within that clade, however, most taxa were recovered in a large polytomy, due to the limited codings available for Acheroraptor.

Evans et al. (2013) also coded the specimens of Acheroraptor (together and separately) into an updated version of the smaller, dromaeosaur-specific dataset from Longrich and Currie (2009). Velociraptor osmolskae and Balaur bondoc were added, Itemirus was excluded (following its identification as a tyrannosauroid by Miyashita and Currie (2009)), and following Turner et al. (2012) the codings for Adasaurus mongoliensis were separated into these based on the holotype from the Nemegt Formation, and these based on IGN 100/23 from the Bayanshiree Formation. Several characters were also rescored and modified, and two maxillary characters were added to the matrix from Turner et al. (2012). This analysis yielded a more resolved topology, placing Acheroraptor in a relatively basal position within the Velociraptorinae, which was otherwise found to include only Asian dromaeosaurids. The cladogram below shows the phylogenetic position of Acheroraptor following this analysis.