December 2021 updates to the bird subset of the LRT

Housekeeping
to the large reptile tree (LRT, 2024+ taxa; subset Fig. 2) moved a few birds around in the last few days. More taxa and a critical review of earlier inductee scores recovered better matches (Fig. 1). Here (Fig. 2) are several novel insights into this trait-based phylogenetic analysis of birds and their extinct ancestors going back at least to the Late Jurassic.

Psophia, the trumpeter, now nests with Chauna, the screamer.
Note the tiny bump on the medial edge of manual digit 1 on Psophia evolves to become the otherwise unique, sharp, defensive spur on Chauna (Fig. 1).

Rhynochetos, the kagu, a traditional flightless enigma taxon
now nests with Megapodius, the scrubfowl. Both are from islands near Australia. Rhynochetos has been a long-running problem for the LRT, and other studies, hopefully finally resolved.

As before, nine Solnhofen birds are included.
They still nest apart from one another (Fig. 2), documenting an earlier radiation than the Late Jurassic. Workers should include all nine, rather than just one traditional Archaeopteryx. The Solnhofen birds are not congeneric (Fig. 4).

The last common ancestor of all living birds,
Archaeorhynchus, lived during the Early Cretaceous, documenting an earlier radiation of basal-most crown birds than the K-Pg boundary.

As before, this trait-based test
(Fig. 2) does not recover a topology that matches genomic (gene-based) studies. The LRT documents a ladder-like or ivy-like branching in the bird clade, rather than a more bushy pattern with larger earlier diverging branches. Thus derived taxa need evolutionary time to appear and basal taxa probably had their genesis closer in time to Early Cretaceous Iteravis (Fig. 3) and Archaeorhynchus at the base of crown birds.

The bird subset of the LRT had its genesis
a decade ago with the ostrich, Struthio, and the chicken, Gallus. Earlier errors were often multiplied until rectified in a continuing process that can only handle a few mismatched taxa at a time. In other words, I am learning something new every day, and these I share with you.

Why did it take so long to better understand bird phylogeny?
Because modern bird phylogenies depend on gene-based scores, the trait-based LRT is plowing into unknown territories. Skull fusion in the beak and cranium led to earlier misunderstandings, clarified only after seeing hundreds of genera (Fig. 2). The work is never done. The LRT is not perfect, but better with every revision.

The ability to quickly view several skeletons and skulls
with color segregated elements on twin monitors made this complex job much simpler. So did relying on the feedback from color-coded branches on the MacClade software tree. Perhaps now you can see now why trait-based bird studies were not done with such a wide gamut of extant and extinct taxa prior to the advent of the computer. Pen and ink outlines on crushed skeletons over a wide gamut of taxa are not as helpful in comparative anatomy. Here identifying every bit of every maxilla with transparent green in Photoshop has been more helpful than a traditional set of arrows and abbreviations. Here the ability to repair earlier misinterpretations proved to be essential, not only for the taxonomist in study mode, but also for transmitting data to readers when conclusions are presented.

This bird subset of the LRT appears to be a novel hypothesis of interrelationships.
If not please provide prior citations so I can promote them here. Do not send gene studies.

References
http://reptileevolution.com/reptile-tree.htm