The genus Acrostichides Fontaine is divided into two subgenera, Acrostichides and Lazaripteris, on the basis of material from the terminal Permian of Siberia. The subgenus Acrostichides comprises four groups of species. ...
The first description of the stratotype of the Ust'-Kel'ter Horizon with its specific characteristics is given. A new stratigraphic unit, the Marininskii Horizon, is distinguished and substantiated, and its stratotype is ...
The validity of the genus Acrostichides Fontaine is argued on the basis of the material from the uppermost Permian of Siberia and the Triassic of China and Iran. The genus and species diagnoses are emended.
The analyzed materials obtained by editorial preparation of a new map series, scale 1 : 1 000 000, and generalization of earlier data show that, contrary to prevailing opinions, the Middle to Upper Carboniferous deposits ...