Kyrgyzsaurus bukhanchenkoi (Alifanov and Kurochkin 2011) considered it the most archaic representative of the family Drepanosauridae (which they wrongly attributed to the Archosauromorpha).
Unfortunately, Alifanov and Kurochkin (2011) did not test their find against a wider gamut of taxa. Alifanov and Kurochkin (2011) also misidentified several bones.
Kyrgyzsaurus is small fenestrasaur with a 1-inch long very open skull and an elongated neck with parallelogram-shaped centra. The scapula is elongated and robust, as in Longisquama. The coracoid is quadrant-shaped, as in other basal fenestrasaurs starting with Cosesaurus. The rostrum was so short that the naris began over the premaxilla, unlike other fenestrasaurs. The skull was shorter than the cervicals, as in Sharovipteryx.
Even though the forelimbs are missing, the elongated scapula and stemmed coracoid are identical to those found in Langobardisaurus and Cosesaurus through pterosaurs. Earlier we discussed how these were different than those of quadrupedal tritosaur lizards and that birds, bats and pterosaurs all have a similar morphology for flapping.
The Madygen Formation also yielded Sharovipteryx and Longisquama, so this is confirmed as the birthplace of the pterosaurs.
Alifanov and Kurochkin (2011) misidentified the dorsal scapula as a single high neural spine. They thought the lower jaw was shorter than the upper at their tips. The occiput was overlooked as it sits on top of the parietal. What they considered the occiput are the first two cervical vertebrae. What they considered the occipital condyle is the posterior cervical vertebrae 2 extending below cervical 3, as in all the other cervical vertebrae and as in pterosaurs and other fenestrasaurs. What they considered broken maxilla is the sclerotic ring. What they considered the sclerotic ring is the squamosal and the postorbital. What they considered the arch of the hypoglossal apparatus is the main portion of the quadrate together with the much thinner hyoid. Their quadrate is the pterygoid process of the quadrate. Their maxilla is actually the ectopalatine (ectopterygoid + palatine). It might have tiny teeth. Their nasal is the ascending process of the premaxilla. The more slender thoracic spine is the ventral stem of a displaced coracoid. The lacrimals and prefrontals were overlooked entirely. |
