Aurorazhdarcho primordius NMB Sh 110 (Frey, Meyer and Tischlinger 2011) reported on a pterosaur that has been known for several years. The authors erected a new family, the Protazhdarchidae and attributed the specimen to the Azhdarchoidea, based on the low glenoid (shoulder joint). No phylogenetic analysis was published. Here, following phylogenetic analysis, along with Wellnhofer's no. 13, Eopteranodon and Eoazhdarcho, Aurorazhdarcho nests at the base of Pteranodon + Nyctosaurus, far from any azhdarchids despite overall appearances.
Apparently without a skull and cervicals, Aurorazhdarcho preserves a faint skull-like patch of golden flakes seen in ultraviolet light. Above, the abstract tracing above the reconstruction of Aurorazhdarcho was taken from this amorphous area. The gray skull and cervicals are a best guess reconstruction. Apparent rows of no. 13-like teeth are barely visible, but let's not put too much stock in those. I don't know what to make of all the curved lines, including a highly curved mandible. Did the fossil soften up before burial? The rest of it did not. Did they get washed away before burial, leaving only drifting impressions? Good question. No answer.
The authors did not make mention of the missing disc-like pedal phalanges (p3.2, p4.2, p4.3) typically found in pterosaurs of this grade, nor did they illustrate them. If the disc-like phalanges were fused to the larger phalanges, or had just disappeared (as in higher cynodonts), that would be news that was apparently overlooked.
Aurorazhdarcho may have had the skinniest legs of all pterosaurs (but see Raeticodactylus for more gracile wings). Compared to its sisters Aurorazhdarcho was more gracile in the wings as well.
The sternal complex is quite large and broad in Aurorazhdarcho and its sisters.
Male or Female? Juvenile or Mature?
Frey, Meyer and Tischlinger (2011) reported, "The partial fusion of the glenoideal suture of the scapulocoracoid and the near complete co-ossification of the olecranon process with the basal wing finger phalanx suggests a late juvenile or subadult individual (cf. Bennett 1993; Frey and Martill 1998)." Unfortunately, these are phylogenetic characters, as we learned earlier. As lizards, pterosaurs don't follow archosaur bone growth patterns (Maisano 2004).
Frey, Meyer and Tischlinger (2011) also reported, "We suggest here that a ventrally open pelvis lacking a puboischiadic symphysis would be indicative for a female because of the wide pelvic apperture would serve as an egg passage (Unwin 2006). Those pterosauria with a tightly fused puboischiadic symphysis and a narrow pelvic aperture like NMB Sh 110 are likely to have been males."
Unfortunately the ventrally open/closed pelvis is also a phylogenetic character. The symphysis is a trait shared with sisters. Fusion of the pubis and ischium occurs in Eopteranodon. |
