Lancrăm near Sebeș-Glod in Transylvania at the SbG-B site uncovered the remains of a pterosaur. He donated these to the Erdélyi Múzeum, of the Societății Muzeului Ardelean (Transylvanian Museum Society). Subsequent excavations by Vremir discovered additional bones of the same individual animal and were added by him to the collection of the Babeș-Bolyai University.[1]
In 2013, Vremir,
PLoS ONE without an accompanying printed version; it nevertheless validly names the taxon under the new rules of the ICZN.[1]
The
metacarpal; the upper part of the first phalanx of the wing finger; the lower part of the second phalanx; a lower phalanx of one of the other fingers and a number of undetermined fragments. The Babeș-Bolyai University material is included within this enumeration and is not indicated by a separate inventory number. Generally the quality of the bones is poor with much of the outer cortex broken or eroded and internal structures present as (impressions of) natural molds. The fossils have not been completely flattened, preserving three-dimensionality, but compression has caused some distortion. The carcass had probably by flooding been deposed on its back in mud near a riverbank. Afterwards it was exposed to the air, weathering and being scavenged as proven by circular bite-marks inflicted by the conical teeth of some member of the Crocodyliformes. Later covered by a thin layer of dirt, it was damaged by beetles and termites.[1]
The authors noted that from the same Romanian layers the related giant form Hatzegopteryx is known; the known fossil material from both genera does not overlap. The authors considered an identity to be unlikely because the much smaller EME VP 312 seems to represent an adult individual.[1]
Description
Silhouette restoration showing the known remains in whiteLife restoration
Eurazhdarcho is a medium-sized
azhdarchid. The authors estimated its wingspan at 3 meters (9.8 ft), extrapolating from an estimated length for the fourth metacarpal of about 25 centimeters (9.8 in).[1]
The authors established some distinctive traits, all present in the cervical vertebrae. The third neck vertebra has three-quarters of the length of the fourth vertebra, whereas 60 percent would be normal with azhdarchids. The necks of the
neural arch are small and placed in a low position.[1]
Phylogeny
Eurazhdarcho was by the authors assigned to the Azhdarchidae, based on the method of
phylogenetic analysis of the Pterosauria, where it was recovered within the family Azhdarchidae.[2] Their cladogram
The area where Eurazhdarcho was found, in the Upper Cretaceous was localized on the
titanosaur Magyarosaurus. This terrestrial fauna suggests that Eurazdarcho was not a coastal piscivore catching fish on the wing, affirming the "superstork" model for azhdarchids, in which they are terrestrial stalkers snatching small prey animals while walking on all fours.[1]
Map of azhdarchid sites with size distinction
If Eurazhdarcho was indeed distinct from Hatzegopteryx, its discovery implies the presence of two azhdarchid forms in the Hațeg fauna, the one gigantic, the other medium-sized. This suggests a
Quetzalcoatlus northropi but also a smaller Quetzalcoatlus sp. and the azhdarchoid represented by specimen TMM 42489-2. The Two Medicine Formation fauna from the Campanian of Montana includes the smaller Montanazhdarcho minor, with a wingspan of 2.5 meters (8 ft 2 in), but also fragments of larger forms with a span of 8 meters (26 ft). In the coeval Dinosaur Park Formation of Canada the smaller specimen RTMP 92.83 was discovered with a wingspan of 5 to 6 meters (16 to 20 ft) but also the large specimen PMA P.80.16.1367 indicating a wingspan of about 10 meters (33 ft) wide.[1][failed verification
