| Aurorazhdarcho Temporal range: Late Jurassic, 150 Ma |
|
|---|---|
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Order: | †Pterosauria |
| Suborder: | †Pterodactyloidea |
| Superfamily: | †Azhdarchoidea |
| Genus: | †Aurorazhdarcho Frey, Meyer & Tischlinger, 2011 |
| Species: | †A. primordius |
| Binomial name | |
| Aurorazhdarcho primordius Frey, Meyer & Tischlinger, 2011 |
|
Aurorazhdarcho is an extinct genus of azhdarchoid pterosaur known from the Late Jurassic of Bavaria, southern Germany.[1]
Contents |
In 1999 amateur paleontologist Peter Katschmekat uncovered a fossil of a pterosaur in the Blumenberg Quarry, three kilometres northwest of Eichstätt, in layers of the Solnhofen limestone. The fossil was prepared by Gerd Stübener and acquired by the Swiss Naturhistorisches Museum Basel. Based on the specimen, the type species Aurorazhdarcho primordius was named and described by Eberhard Frey, Christian A. Meyer and Helmut Tischlinger in 2011. The generic name is derived from Latin aurora, "dawn" and Kazakh Azhdarcho, the name of a mythical dragon. The specific name means "primordial" or "the very first" in Latin.[1]
The holotype of Aurorazhdarcho, NMB Sh 110, was found in the Upper Eichstätt Formation dating to the early Tithonian stage of the Late Jurassic, 150 million years ago. It consists of a nearly complete skeleton, three-dimensionally preserved on a single slab with the counterplate having been removed, lacking the skull and neck. However, the head and neck are present as impressions, movement of these elements on the bottom of the lagoon the carcass descended on leaving a natural mould covered by organic remains in the form of calcium phosphate flakes made visible by the UV-photography of Tischlinger. That the head and neck are now absent is explained by the animal being killed by a partially failed attack by a predator, almost ripping off these parts, after which the body quickly sank. Subsequent bloating would then have caused the head to drift away. The individual was probably subadult and, as indicated by the fusion of the ischiopubes in the pelvis, a male as it lacks a wide birth canal.[1]
Aurorazhdarcho was a relatively small pterosaur. The combined elements of a single wing of the type specimen have the extended length of 537.8 millimetres. 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 shinbone over a third longer than the thighbone. In the wing the metacarpals were very elongated, the fourth metacarpal being longer than the lower arm. The first to fourth phalanges of the wing finger have the respective length of 119, 70.8, 50.8 and 50.6 millimetres.[1]
Aurorazhdarcho was by the describers assigned to the Azhdarchoidea and placed in a new family, the Protazhdarchidae, of which it is the only named member. It would then be the oldest known azhdarchoid with the dubious exception of the "Doratorhynchus" material.[1]
The describers rejected the use of a cladistic analysis to establish the phylogeny. Using the comparative method they found that Aurorazhdarcho was closest in proportions to the ctenochasmatid Ctenochasma elegans, a species also known from the Solnhofen, but they concluded that Aurorazhdarcho belonged to the Azhdarchoidea because it shared certain evolutionary key adaptations with that group, the most decisive of which they considered to be the low shoulder joint. The position of the shoulder joint with Ctenochasma could not be established but the describers assumed it was higher because of the closer relation of that taxon with Pterodactylus.[1]