Xu et al. 2009
described a new genus, Anchiornis huxleyi IVPP V14378 (the holotype), along with LPM-B00169A, BMNHC PH828 as referred specimens), from the Late Jurassic of China. Two of these (Fig. 1) were added to the large reptile tree (LRT, 1315 taxa, subset Fig. 2). They nest in the LRT in the clade traditionally considered Troodontidae, between Velociraptor and Archaeopteryx. (Note other traditional troodontids, like Sinornithoides and Sauronithoides, do not nest in this pre-bird clade, but within the Haplocheirus clade.
a paper by Pei et al. 2017 described “new specimens of Anchiornis huxleyi“. Two of these (Fig. 1) were also added to the LRT (subset in Fig. 2).
In the LRT
only two of the four tested Anchiornis specimens nested together (one was the holotype). That means the two other specimens were originally mislabeled. Moreover, a specimen attributed to a separate genus, Jinfengopteryx, nests with the holotype of Anchiornis and a referred specimen.
So do a few of the referred specimens need to be renamed? Perhaps so. Beyond the distinctly different skulls (Fig. 1), various aspects of the post-crania are also divergent.
(Xu and Zhang 2005; IVPP V 12721, Fig. 3) is a fossil theropod foot with long stiff feathers from the Middle or Late Jurassic, 164mya.
According to Wikipedeia
“Pedopenna was originally classified as a paravian, the group of maniraptoran dinosaurs that includes both deinonychosaurs and avialans (the lineage including modern birds), but some scientists have classified it as a true avialan more closely related to modern birds than to deinonychosaurs.”
The first step
in figuring out what Pedopenna is, is to create a clear reconstruction (Fig. 4). Only then will we be able to score the pedal elements in the LRT.
and despite the relatively few pedal traits, the LRT is able to nest Pedopenna between and among the several Anchiornis specimens (Fig. 5). Specifically it nests between the holotype IVPP specimen and the LPM specimen. So is Pedopenna really Anchiornis? Or do all these taxa, other than the holotype, need their own generic names?
Earlier we looked at the development of foot feathers to aid in stability in pre-birds and other bird-like taxa just learning to flap and fly, convergent with uropatagia in pre-volant pterosaur ancestors.
A note to Anchiornis workers:
Try to test all your specimens in a phylogenetic analysis for confirmation, refutation or modification of the above recovery. Pei et al. considered all the specimens conspecific. They are not conspecific, as one look at their skulls alone (Fig. 1) will tell the casual observer.
Pei R, Li Q-G, Meng Q-J, Norell MA and Gao K-Q 2017. New specimens of Anchiornis huxleyi (Theropoda: Paraves) from the Late Jurassic of Northeastern China. Bulletin of the American Museum of Natural History 411:66pp.
Xu X, Zhao Q, Norell M, Sullivan C, Hone D, Erickson G, Wang X, Han F and Guo Y 2009. A new feathered maniraptoran dinosaur fossil that fills a morphological gap in avian origin. Chinese Science Bulletin 54 (3): 430–435. doi:10.1007/s11434-009-0009-6
Xu X and Zhang F 2005. A new maniraptoran dinosaur from China with long feathers on the metatarsus. Naturwissenschaften. 92 (4): 173–177. doi:10.1007/s00114-004-0604-y.