A rather poorly-known rock formation from Kazakhstan, the best fossil from this area is that of Sordes pilosus.
Sordes is a rhamphorhynchid pterosaur from the Oxfordian to the Kimmeridgian Stages of the Late Jurassic about 155 million years ago.
This genus is the first known for having properly preserved outlines of wing membranes and furry pycnofibers. Another pterosaur from the formation is the anurognathid Batracognathus.
Neither of these genera was very big, around 60 to 75 centimeters across in terms of wingspan.
They both probably ate insects, of which there are plenty in the Karabastau.
Another animal from the area is Karaurus, a salamander.
The other vertebrate from this formation is Karatausuchus, an atoposaur. Atoposaurs are a family of small, terrestrial crocodylomorphs that existed throughout the Jurassic and Cretaceous Periods.
The genus is probably known for soft tissue remains and a few juvenile specimens.