Navaornis, Rhynchotus, Eudromia, Casuarius and Rhea

Navaornis hestia (Chiappe et al 2024, Late Cretaceous) was originally considered a toothless enantiornithine. Here it nests among the tinamous, basal to the larger flightless palaeognaths.

Rhea americana (Linneaus 1758; extant) is the largest rhea of South America. The juvenile has a large thumb claw and unfused fingers. Derived from Megapodius, Rhea is basal to the tinamous and the cassowary (below).

Rhynchotus maculicollis (Temminck 1815, Gray 1867) is a genus from the Tinamidae, or tinamous. Here it nests basal to the much larger Struthio and Casuarius as one of the most primitive of all living birds, transitional to all other extant birds. So here Rhynchotus is a basal ratite, not a tinamou. It prefers to run, but can still fly. Note the long legs and small feet.

Eudromia elegans (Saint-Hiliaire 1832) is the elegant crested tinamou from South America. Not a strong flier, this tinamou hunts and escapes on foot.

Casuarius casuarius (Brisson 1760; up to 2m tall) The extant cassowary is one of the few birds with a bony crest or casque on its head. Derived from a tinamou like Rhynchotus, this flightless omnivore feeds mainly on fruit, shoots and small seeds. The crest shape variws with the individual. Females are larger and more brightly colored. The manus is a fused (undifferentiated) vestige.

Chiappe LM et al (4 co-authors) 1983. Fossil basicranium claried the origin of the avian central nervous system and inner ear. Proceedings of the Royal Society B: Biological Science 289.

Chiappe LM et al (6 co-authors) 2024. Cretaceous bird from Brazil informs the evolution of the avian skull and brain. Nature https://doi.org/10.1038/s41586-024-08114-4

Cracraft J 1981. Toward a phylogenetic classification of the recent birds of the world (Class Aves).Auk98: 681–714.

Geoffroy Saint-Hilaire I 1851. [Note sur les onze espèces nouvelles do Trochilidés de M. Bourcier.] Compt. Rend. de l'Acad. Sci 32:188.

Lambrecht K 1928. Palaeotis weigelti n. g. sp., eine fossil trappe aus der mitteleozanen Braunkohle des Geiseltales. Jahrbuch hallesch. Verband., Halle, n.s., 7:11.

Linnaeus C 1758. Systema naturæ per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata.

Mayr G 2004. Morphological evidence for sister group relationship between flamingos (Aves: Phoenicopteridae) and grebes (Podicipedidae). Zoological Journal of the Linnean Society. 140 (2): 157–169. doi:10.1111/j.1096-3642.2003.00094.x. ISSN 0024-4082.

Milne-Edwards A 1863. Mémoire sur la distribution géologique des oiseaux fossiles et description de quelques espèces nouvelles. Annales des Sciences Naturelles (in French). 4 (20): 132–176.

Milne-Edwards, A 1867-1871. Recherches anatomiques et paleontologiques pour servir a l’histoire des oiseaux fos- siles de la France (Paris, G. Masson).

Temminck 1815. Histoire naturelle generale des pigeons et des gallinaces.
Accompagne de planches anatomiques. 3: 552–747

wiki'Navaornis
wiki/Rhynchotus
wiki/Cassowary
wiki/Elegant_crested_tinamou