Bird from the Na Duong Formation (Eocene of Vietnam) (1 Viewer)

[albertonykus]

Massonne, T., M. Böhme, and G. Mayr (2022)
A tarsometatarsus from the upper Eocene Na Duong Basin—the first Palaeogene fossil bird from Vietnam
Alcheringa (advance online publication)
doi: 10.1080/03115518.2022.2126010

Knowledge of the Palaeogene avifauna of East Asia is scarce, and only a few fossils have been described thus far. A tarsometatarsus from the upper Eocene Na Duong Basin represents the first Palaeogene fossil bird from Vietnam. The fossiliferous sediments in the Na Duong Basin originated from an aquatic ecosystem but also yielded terrestrial animal and plant remains suggesting a dense forest habitat surrounding an ancient lake. In accordance, the Na Duong Basin tarsometatarsus is compared with extant aquatic, terrestrial and arboreal bird species, but because of diagenetic compression and fragmentary preservation, it is difficult to classify the bone. Nevertheless, the specimen exhibits a distinctive morphology and is potentially referable to an endemic neognath unknown from other Palaeogene localities outside of Vietnam.

 

[Fred Ruhe]

Systematic palaeontology

Aves Linnaeus, 1758
Neognathae incertae sedis

Referred material. GPIT-PV-122865, a partial right tarsometatarsus

Locality, unit and age. Layer 80 of the Na Duong coal mine in northern Vietnam (2142.20N, 10658.60E); Na Duong Formation (Na Duong Basin), late Bartonian to Priabonian (late Eocene), 39–35 Ma (Böhme et al. 2013).

Fred


Figure. 1. Neognathae incertae sedis (GPIT-PV-122865). Tarsometatarsus in A, B, dorsal view; C, D, plantar view; E, F, cross-section of the proximal end of the shaft; G, H, distal view; I, J, enlargement of the distal end in dorsal view; K, L, enlargement of the distal end in plantar view. Abbreviations: bw, bone wall; fmt1, fossa metatarsi 1; fvd, foramen vasculare distale; mt, metatarsale; se, sulcus extensorius; tm, trochlea metatarsi. Scale bar ¼ 5 mm.