Beginning in the 1980s, several fragmentary bones of azhdarchid pterosaurs were discovered in rocks of the Upper Cretaceous Bostobe Formation of southwestern Kazakhstan. In 2007 Alexander Averianov assigned many of them to a new genus and species, Aralazhdarcho bostobensis. The name honors the Aral Sea and the formation.
Aralazhdarcho is known from fragmentary skull bones from the cheek region and adjacent parts of the lower jaw, some fragmentary neck and torso vertebrae, part of one scapula, a portion of the second phalanx of the left wing finger, and a fragment of a left femur.
The neck vertebrae include rear portions of the axis and the front portion of the 5th or 6th vertebra. Both vertebrae are very fragmentary, but clearly from an azhdarchid. The mid-neck vertebra serves as the holotype specimen for Aralazhdarcho. Like other azhdarchids, its overall shape is like a flattened spool. The neural canal is tall and elliptical, and one small pneumatic pore is present on either side of the neural canal.
The skull fragments, scapula, wing finger phalanx, and femur all show similarities to other azhdarchids. The size of Aralazhdarcho is difficult to determine, but comparisons to other azhdarchids suggest that it was a smaller animal, with a wingspan of about 3 meters (10 feet).
The Bostobe formation was formed in an estuary environment about 80 million years ago. At the time, much of Europe was covered by shallow seas. The adjacent continental landmass to the north was temperate to semi-arid. The Bostobe formation is home to a number of dinosaurs including fragmentary theropods from at least four families, and the ornithopods Aralosaurus and Batyrosaurus. Azhdarchids were hunters of terrestrial prey, and Aralazhdarcho may have hunted on land or perhaps the shore of the estuary.
Azhdarchidae