Dwarf fauna from the Lower Carboniferous of Jingtai, Gansu, China

A dwarf fauna is found from the Lower Carboniferous of Jingtai, Gansu, which is mainly composed of corals, brachiopods, bryozoans and crionoids. The fossils are all small sized, usually only several millimeters. The diameters of the coral fossils are 2.5~11.0 mm and most are less than 6.0 mm. In the brachiopods, the length or the width of the smallest specimens is only 3.0 mm and the sum of the length and the width of over 50% of them is less than 11.0 mm. This assemblage is believed neither a catastrophic death group, nor a transported shell accumulation, but a specific fauna whose growth retarded because of some unusual living conditions.