Revised December 13, 2021 with new scores and a revised LRT.
The spark for this blogpost:
A reader considered the nesting of the sandgrouse Pterocles with the horned screamer, Anhima, a mismatch. And it is a mismatch in terms of size, color, feet, legs, etc. It is also a mismatch in the revised large reptile tree (LRT, 2018 taxa, Fig. 1). Pterocles nests with pigeons. Anhima, the screamer, nests with Psophia, the trumpeter.
Earlier I only had skull data (Fig. 4) for the genus Pterocles (Figs. 1–3) and with that heretically nested Pterocles, the sand grouse, with Anhima, the screamer (Fig. 2). Sand grouse have traditionally been nested with pigeons and chickens, or between pigeons and chickens (Shufeldt 1901).
Back in 1901
Shufeldt reported, “the sand grouse constitute a small assemblage of forms, related on one hand to the gallinaceous (chicken-like) birds, and on the other to the pigeons.”
Shufeldt RW 1901. On the systematic position of the sand grouse (Pterocles: Syrrhaptes). The American Naturalist 35 (409):11–16.