The analysis of coal-petrology and geochemistry were carried out for Devonian cutinite coal in Luquan Region

Yunnan

so that abundant tetracyclic diterpanoid with the skeletons of phyllocladene and kaurene were determined

but the contents of pristane and phytane were very little or nothing. According to paleoplant study

the coal-forming materials were mainly the short plants of Psilopsid and Lycoposida. It is inferred that the tetracyclic diterpanes were not derived from the resinites which were considered from gymnospermous

but may derived from pteridophytes or non-cyclic isoprenoid alkanes that were reformed by bacteria. This will be further studied in thermo-simulation of organic matter.