Aurorazhdarcho
Aurorazhdarcho | |
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Specimen formerly referred to Pterodactylus longirostris, Muséum national d'histoire naturelle in Paris | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Order: | †Pterosauria |
Suborder: | †Pterodactyloidea |
Family: | † Aurorazhdarchidae
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Genus: | †Aurorazhdarcho Frey, Meyer & Tischlinger, 2011 |
Species: | †A. micronyx
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Binomial name | |
†Aurorazhdarcho micronyx (Meyer, 1856)
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Synonyms | |
List
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Aurorazhdarcho is an
History
First discovery
A specimen, originally classified as
The Pester Exemplar consists of a jumbled and partially dis-articulated juvenile pterosaur skeleton lacking a skull. Because of this, and the unusual (and at the time totally unknown) anatomy of pterosaurs, the specimen was originally misidentified as a
In 1856,
Discovery of adult specimen
In 1999, amateur paleontologist Peter Kaszmekat uncovered a fossil of a pterosaur in the Blumenberg Quarry, 3 kilometers (1.9 mi) northwest of
The
In 2013, Bennett compared the holotype specimen of Aurorazhdarcho primordius to the specimens of the species "Pterodactylus" micronyx (named by Christian Erich Hermann von Meyer in 1856). He found that some of the supposed distinguishing features of A. primordius, such as length of the metacarpal IV equal to the length of the radius and ulna, or first wing finger phalanx being the longest element in the wing, are in fact also present in the skeletons of the specimens of "P." micronyx; in addition, limb proportions in the holotype specimen of A. primordius matched those of "P." micronyx. Bennett concluded that Aurorazhdarcho primordius and "Pterodactylus" micronyx are in fact conspecific; he retained Aurorazhdarcho as a genus distinct from Pterodactylus, but he considered the specific epithet primordius to be a junior synonym of the epithet micronyx.[3]
As noted by Bennett, the taxonomy of Aurorazhdarcho micronyx is further complicated by the author's earlier suggestion[4] that "Pterodactylus" micronyx specimens are in fact juveniles of Gnathosaurus subulatus, which if confirmed would make the former a junior synonym of the latter. G. subulatus is only known from the holotype incomplete mandible and the isolated skull;[3] this makes comparison difficult, because skulls are only known in small, juvenile specimens of A. micronyx, while the large specimens, including NMB Sh 110, lack it. Thus, Bennett stated that until a large specimen with an associated skull and skeleton is discovered, which would make it possible to establish or reject the synonymy of Gnathosaurus and Aurorazhdarcho, the genus Aurorazhdarcho should be used to contain the species A. micronyx.[3]
Additional likely synonyms of P. micronyx are Pterodactylus nettecephaloides and P. redenbacheri. While both of these names are older than A. micronyx, Olshevsky in 1991 considered them
Description
Aurorazhdarcho was a relatively small pterosaur. The combined elements of a single wing of the type specimen have the extended length of 537.8 millimeters (21.17 in). The impressions indicate the head was elongated with the eye socket in a high position. The snout might have carried a high, rounded, crest. The impression of the neck is relatively short and shows signs of a throat pouch.[1]
The shoulder girdle was by the describers reconstructed with a low shoulder joint. The legs were relatively long with the
As mentioned before, the skull is only known in small, juvenile specimens. The skull was elongate, with its superior margin markedly concave upward, and slender, elongated rostrum. Its jaws had up to 18 closely spaced, long, gently curving teeth per jaw side. The anterior teeth were angled anteriorly, while the posterior teeth were shorter and more upright. The upper and lower teeth interlocked; according to Bennett (2013) they formed a basket for sieving food items from water,[3] though the lack of a pumping mechanism suggests a function more akin to spoonbill jaws, wading with the jaws open and closing them when catching individual prey, much as in other ctenochasmatoids.[6]
Phylogeny
Aurorazhdarcho was by the describers assigned to the
The describers rejected the use of a
Bennett in 2013, based on the analysis of all known specimens of Aurorazhdarcho micronyx and taking its short neck and pedal morphology into account, considered this species to be a ctenochasmatid.[3]
Below is a
Ctenochasmatoidea |
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See also
References
- ^ .
- ^ a b c Ősi, A., Prondvai, E., & Géczy, B. (2010). The history of Late Jurassic pterosaurs housed in Hungarian collections and the revision of the holotype of Pterodactylus micronyx Meyer 1856 (a ‘Pester Exemplar’). Geological Society, London, Special Publications, 343(1), 277–286.
- ^ .
- .
- ^ Olshevsky, G. (1991). "A revision of the parainfraclass Archosauria Cope, 1869, excluding the advanced Crocodylia" (PDF). Mesozoic Meanderings (2). Archived from the original (PDF) on August 19, 2018. Retrieved January 5, 2013.
- ISBN 0691150613.
- doi:10.1144/SP455.12.