Anatomy and Flight Performance of the Early Enantiornithine Bird Protopteryx fengningensis (2 Viewers)

[Fred Ruhe]

A paper I forgot to mention:

Luis M. Chiappe, Liu Di, Francisco J. Serrano, Zhang Yuguang & Qingjin Meng, 2020

Anatomy and Flight Performance of the Early Enantiornithine Bird Protopteryx fengningensis: Information from New Specimens of the Early Cretaceous Huajiying Formation of China.

The Anatomical Record 303(4): 716-731
doi: https://doi/10.1002/ar.24322
https://anatomypubs.onlinelibrary.wiley.com/doi/10.1002/ar.24322

Free pdf: https://anatomypubs.onlinelibrary.wiley.com/doi/pdf/10.1002/ar.24322


Abstract:

The Early Cretaceous (131 Million Years Ago) Protopteryx fengningensisis one of the oldest and most primitive enantiornithine birds; however, knowledge of its anatomy has largely been limited to the succinct description of two specimens (holotype and paratype). This study describes two new specimensof P. fengningensis preserving most of the skeleton and plumage, and it therefore adds significantly to understanding the morphology of this important spe-cies and the character evolution of enantiornithine birds. The well-preserved plumage of these specimens also affords a quantitative assessment of the flight performance of P. fengningensis. Our aerodynamic considerations indicate that this early enantiornithine was capable of intermittent flight (bounding or flap-gliding), thus marking the earliest occurrence of suchenergy-saving aerial strategy.


Enjoy,

Fred

 

[Fred Ruhe]

Systematic Paleontology

Aves Linnaeus, 1758.
Pygostylia Chiappe, 2002.
Ornithothoraces Chiappe, 1995.E
nantiornithes Walker, 1981.
Protopteryx fengningensis Zhang and Zhou, 2000.

Holotype. IVPP V11665, nearly complete skeleton con-tained in two slabs (Fig. 1)

Referred specimens.

IVPP V11884, nearly comlete skeleton contained in two slabs. IVPP V11884 was identified as the paratype by Zhang and Zhou (2000)—this specimen was incorrectly listed as the holotype in Zhang and Zhou’s (2000) Fig. 3. BMNHC Ph 1060 and BMNHC Ph 1158, these two new specimens are also conained in two slabs (Figs. 2 and 3). They are articulatedand complete, preserving much of their plumage. An incomplete specimen (BMNHC Ph 1424) contained in two slabs from Weichang County (Hebei Province) may also be assignable to this species; none the less, this specimen requires further preparation and study.

Geographic and stratigraphic provenance.

All documented specimens come from the Sichakou locality in Fengning County, northern Hebei Province, northeastern China (Fig. 1) (if BMNHC Ph 1424 were to be confirmed as belonging to P. fengningensis, it would slightly extend the geographic range of this species to the northernmost por-tion of Hebei Province). All the Sichakou specimens were recovered from shales interbedded in fluviolacustrine sequence rich in pyroclastics sediments (Jin et al., 2008). While the Sichakou locality is currently interpreted as being contained within the Huajiying Formation, it was formerly regarded as belonging to the younger Yixian Formation (see Zhang and Zhou, 2000). The age of the Huajiying Formation has been estimated as approximately 131 MYA (Jin et al., 2008), corresponding to the Hauterivian Epoch of the Cretaceous.

Emended diagnosis.

Medium-sized enantiornithinewith the following combination of traits: long and bowed proximal phalanx of alular digit (alular digit/major metacarpal length ratio is 0.84, much greater than in other enantiornithines from the Huajiying Formation); proximal phalanx of major digit considerably shorter than intermediate phalanx of same digit; coracoid with small procoracoid process; coracoid with a hooked sternolateral process; V-shaped caudal margin of sternum devoid of medial trabeculae; caudoventrally projected cranioventral corner of ilium; ischium almost as long as pubis; metatarsal I has approximately 25% the length of the metatarsus.

Fred


Fig. 1. Holotype of P. fengningensis (IVPP V1165) and map indicating the Sichakou locality in Fengning County (northern Hebei Province, northeastern China), where all documented specimens of this species
come from.



Fig. 2. BMNHC Ph 1060, a new referred specimen of P. fengningensis. Main slab (A, BMNHC Ph 1060a) and counterslab (B, BMNHC Ph 1060b). Inset in (A) highlights details of primary remiges and their rachises photographed under ultraviolet illumination. Abbreviations: co, coracoid; f, femur; h, humerus; mc, metacarpus; mt, metatarsus; of, ornamental feathers; pu, pubis; py, pygost

yle; r, radius; st, sternum; ti, tibia; u, ulna.