Abstract: With a careful study of the external forms and the cuticles of the fossil leaves, a species of Thinafeldia, which was collected from Langdai, Liuzhi County of Guizhou Province, has been identified as T. rhomboidalis Ett. Compare with two other species T. alethopteroides Sze and T. laxa Sze found in Yanchang Formation, Northern Shaanxi, which showed very similar external form (no cuticle structure) of T. rhomboidalis, therefore it is appropriate to clarify them as T. rhomboidalis. As for the genus Thinnfeldia, based on the study of Chinese material, the author set forth her opinion that Thianfeldia should be a separate genus instead of merging into the genus of Pachypteris as has been clarified by many palaeobotanists.

Key words: Thinnfeldia rhomboidalis, Thinnfeldia alethopteroides, Thinnfeldia laxa, Pachypteris, Late Triassic