Jeholopterus

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Jeholopterus Fossil range: Middle Jurassic?
Skeletal reconstruction of Jeholopterus ningchengensis.
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Sauropsida Order: Pterosauria Suborder: Rhamphorhynchoidea Family: Anurognathidae Genus: Jeholopterus Wang et al., 2002
Species
J. ninchengensis Wang et al., 2002 (type)

Jeholopterus was a small anurognathid pterosaur from the Daohugou Beds of northeastern China (of uncertain age, possibly Middle Jurassic or Early Cretaceous), preserved with hair and skin impressions, and named after its place of discovery, Jehol in China.

The type, and only known, species is Jeholopterus ninchengensis, based on a nearly complete specimen (IVPP V12705) from the Daohugou beds of Ningcheng County in the Neimongol (Inner Mongolia) Autonomous Region of China.^[1] The specimen is crushed into a slab and counterslab pair, so that parts of the specimen are preserved on one side of a split stone and some on the other. This includes exquisite preservation of carbonized skin fibers and, arguably, "hair" or "protofeathers." The fibers are preserved around the body of the specimen in a "halo." Wing tissue is preserved, though its extent is questionable, including the points of attachment to the legs (or if it attached to the legs at all).

As an anurognathid, Jeholopterus is notable for its unusual skull, which was wider than it was long, with a very broad mouth. The wings of Jeholopterus show evidence that they attached to the ankle, according to Wang et al., who also argue that it had a short tail, a feature seen in other anurognathids but unusual for "rhamphorhynchoid" pterosaurs. Wang et al. cited the presence of a fringe of hair in the region of the tail to infer the presence of a short tail. However, a subsequent study by Dalla Vecchia argued that gleaning any information about the tail is impossible, given that the tail is "totally absent" in the fossil.^[2]

Contents 1 Alternative interpretations 2 See Also 3 References 4 External links

[edit] Alternative interpretations

Though he never examined the fossil himself, advertising artist David Peters has popularized his idiosyncratic opinions about Jeholopterus and other pterosaurs widely on the internet. In general he finds and illustrates hosts of ornamental features and even multiple embryos although no other researchers have ever confirmed his findings. By manipulating downloaded images of Jeholopterus in the computer art program Photoshop, David Peters (2003) reported that he discovered an unusual suite of soft-tissue remains, including a horse-like tail Peters speculated may have been used as a fly sweeper/distractor, as well as a long fly lure (similar to that of the anglerfish) protruding from the head, and a fin or series of fins along the back. Peters also reported that he had found "rattlesnake-like fangs", and these, along with what he described as a rattle-snake-like mandible, buttressed palate, "surgically-sharp" unguals, robust limbs and other characters suggested that Jeholopterus was a vampire pterosaur adapted to plunging fangs into tough hide, then rotating the skull forward locking the fangs beneath the hide to improve adhesion. The small teeth of the lower jaw would not have penetrated but squeezed the wound like a pliers.^[3] Prominent pterosaur researcher Chris Bennett has described Peters' findings as "fantasy" and has vehemently denounced his methodology.^[4]

Contrary to the work of Peters, however, when looking at the crushed, flattened, and disfigured holotype skull of Jeholopterus (see above), it is not possible to be precise about fine features aside from general shapes of some of the larger bones. The skull is preserved in dorsal view, so that the palate (and thus the precise arrangement, shape, and size of the teeth) are obscured, along with details of the palate, and the shape and aspect of the cranial bones in lateral view. This is a caution for all skeletal reconstructions made from crushed specimens. Even high quality photos are probably inadequate evidence when compared to the dissecting microscopes used by actual paleontologists.^[4][3]

One succinct example is this: A bone identified by Peters as a portion of a long, fang - like, tooth is most likely; 1) two juxtaposed teeth, lying one atop the other, 2) a long bone broken at the end, or 3) a single tooth broken along the crown.

[edit] See Also

Longisquama

[edit] References

[edit] External links

• Discussion of the validity and uses of computer tracing techniques, from the Dinosaur Mailing List