According to Worthy et al. 2016
“Numerous phalanges are known for Sylviornis neocaledoniae. While no articulated material is known, the collection reveals that this bird had the usual digital formula of 2:3:4:5 for digits I to IV as shown in a composite set (Fig 11, here Fig. 1) assembled based on matching size of the elements from The Pocket, in Cave B.”
Sylviornis neocaledoniae (Poplin 1980, recently extinct) was originally considered a ratite, then a megapode, then a stem chicken (Gallus), not quite a meter in length. Here it nests at the base of the hook-beaked predatory birds between Sagittarius and Cariama. The premaxilla forms a crest. The narrow rostrum is mobile relative to the wide cranium. We looked at Sylviornis earlier here.
On a similar note…
I found this skeleton of Phoenicopterus, the flamingo (Fig. 3), with its toes switched on this unknown museum mount. The preparators should have mounted digit 2 medially and digit 4 laterally.
Poplin F 1980. Sylviornis neocaledoniae n. g., n. sp. (Aves), ratite éteint de la Nouvelle-Calédonie. Comptes Rendus de l’Académie des Sciences, Série D (in French). 290: 691–694.
Worthy TH et al. 2016. Osteology Supports a Stem-Galliform Affinity for the Giant Extinct Flightless Bird Sylviornis neocaledoniae (Sylviornithidae, Galloanseres). PLoS ONE 11(3): e0150871. doi:10.1371/journal.pone.0150871