In contrast to 213, no terrigenous influx.
Corals rare in reefs, but abundant on platform.

Four reef mountains (shikhans) in area. From N-S:
Yuaktau
Kushtau
Shakhtau
Tratau
Surface outcrop thickness 250-300 m. Well data > 500 m.
Main reef builders: Tubiphytes, Palaeoaplysina, bryozoans, rare corals and other algae.
35 species of algae
2 species of stromatolites
3 species of sponges
80 species of bryozoans
30 species of corals.

Reefs (also in subsurface with steep eastern slopes (45-50°) and gentle western slopes (5-12°).

Abstract of ref. 1565:
In the geological record, paleontological taxa of uncertain affinity are receiving increasing attention in order to provide paleoecological data for paleoenvironment reconstructions. The present study deals with the taxon Tubiphytes and analyses some of its synecologic interactions, its role played in influencing community structure and its suspected affinity. Tubiphytes is an important skeletal framework element that occurs in several Lower Permian reef mounds of southern Urals (Russia). Tubiphytes acted as an incrusting, a binding organism and a support for others organisms both in Tratau and Nizhni-Irginsk reef mounds. Tubiphytes is constituted of a dark meshwork, microlaminated, and developed around an internal cavity. Thus, this taxon is restricted to the surrounding envelop. Three morphotypes have been recognized within these buildups, according to the shape and characteristics of their surrounding envelops. Therefore, the internal cavity of Tubiphytes can be represented by a sparitic hole or a preserved organic structure. Two assemblages of Tubiphytes with others organisms can be proved in the Uralian reef mounds: the combination of Tubiphytes with bryozoan zooecial and foraminifer structures. 