Anchiornis and feather molting 2025

From the publicity (linked below)
“A new study led by a researcher from the School of Zoology and the Steinhardt Museum of Natural History at Tel Aviv University examined dinosaur fossils preserved with their feathers and found that these dinosaurs had lost the ability to fly. According to the researchers, this is an extremely rare finding that offers a glimpse into the functioning of creatures that lived 160 million years ago, and their impact on the evolution of flight in dinosaurs and birds.”

After analysis
in the large reptile tree (LRT, 2340 taxa), Anchiornis is a feathered pre-bird four nodes more primitive than Solnhofen birds and unable to flap due to its short, squarish coracoids.

Xu et al 2009 described Anchiornis and did not consider it a bird.
Kiat et al 2025 did not include the word ‘coracoid’ in their text. Their study focused on molt patterns, which differ among volant and non-volant taxa.

Kiat et al reported,
“we built two cladograms based on the tree used by Kiat and O’Connor (2024) representing the evolutionary relationships of paravians (including Neornithes), encompassing about 160 million years, including three Mesozoic taxa: Anchiornis, Microraptor and Confuciusornithiformes. Although findings regarding molt strategy have been published for an additional Mesozoic bird, Archaeopteryx, these findings remain disputed⁷⁴, and therefore, this taxon was not included in our analysis.”

“Two alternative cladograms were required because of the uncertainty regarding the phylogenetic position of Anchiornis, as either a non-avian avialan or a non-avian deinonychosaur. Neornithine evolutionary relationships are based on an
analysis of global bird diversity and the BirdTree project and revised based
on more recent avian phylogeny.”

These are all genomic analyses, so they have maor flaws and do not include fossil taxa. That’s why Kiat et al reported the cherry-picked fossil taxa they somehow added.

Anchiornis huxleyi
(Xu et al. 2009, Late Jurassic, Oxfordian, 34 cm, holotype: IVPP V14378) was originally and correctly identified as a proto-bird. Derived from a sister to Jinfengopteryx, Anchiornis is basal to Aurornis. It has large wing feathers, long leg feathers and short tail feathers, plus a crest of feathers over its head and plumage covering the body.

References
Kiat Y and O’Connor JK 2024. Functional constraints on the number and
shape of flight feathers. Proc. Natl Acad. Sci. USA 121, e2306639121.
Kiat, Y., Wang, X., Zheng, X. et al. 2025. Wing morphology of Anchiornis huxleyi and the evolution of molt strategies in paravian dinosaurs. Commun Biol 8, 1633 (2025). https://doi.org/10.1038/s42003-025-09019-2
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

wiki/Anchiornis

Publicity
The dinosaur that forgot to fly