O tecido mole do Jeholopterus e a estrutura da membrana da asa do pterossauro

The soft tissue of Jeholopterus (Pterosauria, Anurognathidae, Batrachognathinae) and the structure of the pterosaur wing membrane

Alexander W. A. Kellner1,*, Xiaolin Wang2,*, Helmut Tischlinger3, Diogenes de Almeida Campos4, David W. E. Hone2 and Xi Meng2,5

- Author Affiliations

1Setor de Paleovertebrados, Museu Nacional/UFRJ, Quinta da Boa Vista s/n., São Cristóvão, Rio de Janeiro 20940-040, Brazil

2Key Laboratory of Evolutionary Systematics of Vertebrates, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, PO Box 643, Beijing 100044, People's Republic of China

3Tannenweg 16, 85134 Stammham, Germany

4Museu de Ciências da Terra/DNPM, Avenve Pasteur 404, Urca, Rio de Janeiro 22290-240, Brazil

5Graduate University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China

*Authors for correspondence (kellner@mn.ufrj.br, xlinwang@263.net).

Abstract

The soft tissue preserved in the holotype (IVPP V12705) of Jeholopterus ningchengensis from the Daohugou Bed (Late Jurassic or Early Cretaceous) of China is described in detail. The plagiopatagium can be divided into the distal, comparatively more rigid actinopagatium and a proximal, more tensile tenopatagium. The actinopatagium extends from the wing finger to the articulation between the humerus and the forearm, and shows the presence of at least three layers containing actinofibrils. In each layer, the actinofibrils are parallel to subparallel, but this direction diverges from layer to layer. When distinct layers of actinofibrils are superimposed (owing to taphonomic compression), a reticular pattern is generated. The presence of layers with differently oriented actinofibrils is widespread in this pterosaur. A well-developed integumental covering formed by fibres (here named pycnofibres) that are thicker than the actinofibrils is present. Ungual sheaths that extend the length of the pedal and manual claws of this taxon are also observed. Although the understanding of the mechanical properties of the wing membrane is hampered by the lack of knowledge regarding the composition of the actinofibrils, the configuration observed in Jeholopterus might have allowed subtle changes in the membrane tension during flight, resulting in more control of flight movements and the organization of the wing membrane when the animal was at rest.

Pterosauria soft tissue wing membrane Jeholopterus Daohugou Bed China

Footnotes

One contribution to a Special Issue ‘Recent advances in Chinese palaeontology’.
Received May 17, 2009.
Accepted June 22, 2009.
© 2009 The Royal Society

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