Pterorhynchus

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Pterorhynchus
Temporal range:
Ma
Skeletal reconstruction showing known material
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Order: Pterosauria
Clade:
Darwinoptera
Genus: Pterorhynchus
Czerkas & Ji, 2002
Type species
Pterorhynchus wellnhoferi
Czerkas & Ji, 2002

Pterorhynchus ("wing snout") is an extinct

China
.

The genus was named in 2002 by

Stephen Czerkas and Ji Qiang. The type species is Pterorhynchus wellnhoferi. The genus name is derived from Greek pteron, "wing" and rhynchos, "snout", in reference to the tall crest on the head. The specific name honours the German pterosaur researcher Peter Wellnhofer
.

The genus is based on holotype CAGS02-IG-gausa-2/M 608 (earlier DM 608). It was found in Chifeng in the Daohugou Beds. According to Ji Pterorhynchus belongs to the Yanliao Biota from the Haifanggou Formation of the Callovian; Lü Junchang in 2007 ascribed it to the somewhat later Tiaojishan Formation of the same stage.

Description

The only known specimen had an elongated skull 11.8 centimetres (4.6 in) long, a long tail and a

rhamphorhynchoid" tails, and a head crest with both a low bony base and a large keratin
extension; the latter feature is unusual in "rhamphorhynchoids" (i.e. basal pterosaurs), the fossils of which do not often show head crests. The front part of the extension continued the leading margin of the bone base, extending at quite a sharp angle; it finally curved back to the base of the skull in a rounded curve. The crest covered the posterior two thirds of the head, showed the presence of minute oval scales and was reinforced by a dozen ridges running parallel to the rounded trailing edge. At the base a vertical pattern was visible, interpreted as corresponding to the original camouflage colour patterning. The describers ascribed a primarily aerodynamic function to the crest, which is reflected in the genus name.

Hair-like

pycnofibers covered the body, and tiny tufts of fibers also covered portions of the wing membrane. These were described as pinnate, with many strands arising from a single base (similar to the calamus of the down feathers in birds), and seen as corresponding to the hypothetical Stage II in the evolution of feathers. This would suggest that pterosaur pycnofibres and dinosaur feathers were homologous.[2] Later researchers—in a detailed study of pterosaur integument—recognized distinct tufts of fibers, but did not find evidence for the reported diamond-shaped patterns supposedly formed by these tufts when they examined the published photographs. However, they disagreed with the interpretation that the small nodules at the bases of some tufts were similar to a calamus, because they did not appear to be hollow.[3]

Classification

The scientists who first studied it assigned Pterorhynchus to the

See also

References

  1. .
  2. .
  3. ^ Kellner, A.W.A., Wang, X., Tischlinger, H., Campos, D.A., Hone, D.W.E., Meng, X. 2010. The Soft-Tissue of Jeholopterus (Pterosauria, Anurognathidae, Batrachognathinae) and the Structure of the Pterosaur Wing Membrane. Proc. R. Soc. B. Vol. 277:321–329.
  4. ^ .
  5. .

External links