Thursday, September 21, 2017

[PaleoOrnithology • 2017] Late Pleistocene Songbirds of Liang Bua (Flores, Indonesia); The First Fossil Passerine Fauna Described from Wallacea


Figure 3: Late Pleistocene passerines from Liang Bua.
 (A) Left tarsometatarsus of Philemon sp. (LB-Av-740), (B) left tarsometatarsus of P. buceroides (NMNH 347688); (C) right femur of Philemon sp.(LB-Av-795), (D) right femur of P. buceroides (NMNH 347688); (E) right tibiotarsus of cf. Philemon (LB-Av-857), (F) right tibiotarsus of P. buceroides (NMNH 347688), (G) left tibiotarsus (LB-Av-726) of cf. Philemon, (H) right tibiotarsus (LB-Av-775) cf. Philemon;
(I) right humerus of Rhipidura sp. (LB-Av-762), (J) right humerus of R. albicollis (NMNH 620568);
 (K) distal fragment of right humerus of Corvus cf. macrorhynchos (LB-Av-856), (L) right humerus of C. macrorhynchos (NMNH 641775); (M) right scapula of Corvus cf. macrorhynchos (LB-Av-766), (N) right scapula of C. macrorhynchos (NMNH 641775).
 (scale bars 1 cm) DOI: 10.7717/peerj.3676

Abstract

Background
Passerines (Aves: Passeriformes) dominate modern terrestrial bird communities yet their fossil record is limited. Liang Bua is a large cave on the Indonesian island of Flores that preserves Late Pleistocene–Holocene deposits (∼190 ka to present day). Birds are the most diverse faunal group at Liang Bua and are present throughout the stratigraphic sequence.

Methods
We examined avian remains from the Late Pleistocene deposits of Sector XII, a 2 × 2 m area excavated to about 8.5 m depth. Although postcranial passerine remains are typically challenging to identify, we found several humeral characters particularly useful in discriminating between groups, and identified 89 skeletal elements of passerines.

Results
At least eight species from eight families are represented, including the Large-billed Crow (Corvus cf. macrorhynchos), the Australasian Bushlark (Mirafra javanica), a friarbird (Philemon sp.), and the Pechora Pipit (Anthus cf. gustavi).

Discussion
These remains constitute the first sample of fossil passerines described in Wallacea. Two of the taxa no longer occur on Flores today; a large sturnid (cf. Acridotheres) and a grassbird (Megalurus sp.). Palaeoecologically, the songbird assemblage suggests open grassland and tall forests, which is consistent with conditions inferred from the non-passerine fauna at the site. Corvus cf. macrorhynchos, found in the Homo floresiensis-bearing layers, was likely part of a scavenging guild that fed on carcasses of Stegodon florensis insularis alongside vultures (Trigonoceps sp.), giant storks (Leptoptilos robustus), komodo dragons (Varanus komodoensis), and probably H. floresiensis as well.


Hanneke J.M. Meijer​, Rokus Awe Due​, Thomas Sutikna, Wahyu Saptomo, Jatmiko, Sri Wasisto, Matthew W. Tocheri and Gerald Mayr. 2017. Late Pleistocene Songbirds of Liang Bua (Flores, Indonesia); The First Fossil Passerine Fauna Described from Wallacea.
 PeerJ. 5: e3676.  DOI: 10.7717/peerj.3676

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